From jryan at caminofx.org  Fri Dec  1 07:35:19 2006
From: jryan at caminofx.org (Jared Ryan)
Date: Fri, 1 Dec 2006 07:35:19 -0600 (CST)
Subject: [Gmecm] TBI conversion
In-Reply-To: <20061130.225005.280.0.bcroe@juno.com>
References: <20061130.225005.280.0.bcroe@juno.com>
Message-ID: <Pine.LNX.4.63.0612010734090.23253@kingfisher.caminofx.org>

I believe that is correct.  I had to change the MAP sensor when I 
converted my CCC El Camino to TBI.  I used one specified for a full-size 
pickup.  The CCC carburetor system also had a barometric pressure sensor 
under the dashboard behind the glove box, separate from the MAP sensor.

On Thu, 30 Nov 2006, bcroe at juno.com wrote:

> My understanding is EFI cars have true MAP sensors, but
> CCC engines have a sensor referenced to air pressure (as
> opposed to absolute zero pressure), is that right?
>
> Bruce Roe
>
> 30 Nov 06  davesnothereman at netscape.net writes:
>>
>>  -----Original Message-----
>>  From: dunvegan at sbcglobal.net
>>  To: gmecm at diy-efi.org
>>  Sent: 30 Nov 06 11:59 AM
>
>>    * MAP sensor (this is still an outstanding question, will
>> probabally have to acquire correct one) My sources show
>> a valid 90 TBI 305 P/U part # as  OEM to be 16137939 but
>> the parts houses show it to be 16137039, so am a little
>> puzzled here.
>>
>> You almost have to try to get a wrong MAP sensor.  Any of
>> the TBI V8 vehicles will supply one which will work.
>
>> Zaphod
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>


From william.lucke at highspeedlink.net  Fri Dec  1 11:31:25 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Fri, 01 Dec 2006 12:31:25 -0500
Subject: [Gmecm] Re: Gmecm Digest, Vol 22, Issue 1
Message-ID: <457066ED.9050402@highspeedlink.net>

Dual use coolant sensor info: http://theherd.com/articles/lt4_temp.html
(single sensor for both gauge and ECM)


Will


> Date: Thu, 30 Nov 2006 12:12:43 -0600 (CST)
> From: Jared Ryan <jryan at caminofx.org>
> Subject: RE: [Gmecm] TBI conversion
> To: gmecm at diy-efi.org
> Message-ID:
> 	<Pine.LNX.4.63.0611301211550.21658 at kingfisher.caminofx.org>
> Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
> 
> A Chevy V-8 has two coolant sensors.  There is one on the intake manifold, 
> in or near the thermostat housing.  That is for the ECM.  There is another 
> one in the driver-side cylinder head.  That is for the gauge in the 
> dashboard.  They are totally separate.
> 
> On Thu, 30 Nov 2006, Steve Ravet wrote:


From dunvegan at sbcglobal.net  Fri Dec  1 11:55:29 2006
From: dunvegan at sbcglobal.net (Rick McLeod)
Date: Fri, 1 Dec 2006 09:55:29 -0800 (PST)
Subject: [Gmecm] Re: Gmecm Digest, Vol 22, Issue 1
Message-ID: <20061201175529.83497.qmail@web80511.mail.yahoo.com>

Cool!!!!!!!!!!

solves the problem, thanks for sticking your 2c worth, much appreciated.


----- Original Message ----
From: William Lucke <william.lucke at highspeedlink.net>
To: gmecm at diy-efi.org
Sent: Friday, December 1, 2006 11:31:25 AM
Subject: [Gmecm] Re: Gmecm Digest, Vol 22, Issue 1


Dual use coolant sensor info: http://theherd.com/articles/lt4_temp.html
(single sensor for both gauge and ECM)


Will


> Date: Thu, 30 Nov 2006 12:12:43 -0600 (CST)
> From: Jared Ryan <jryan at caminofx.org>
> Subject: RE: [Gmecm] TBI conversion
> To: gmecm at diy-efi.org
> Message-ID:
>     <Pine.LNX.4.63.0611301211550.21658 at kingfisher.caminofx.org>
> Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
> 
> A Chevy V-8 has two coolant sensors.  There is one on the intake manifold, 
> in or near the thermostat housing.  That is for the ECM.  There is another 
> one in the driver-side cylinder head.  That is for the gauge in the 
> dashboard.  They are totally separate.
> 
> On Thu, 30 Nov 2006, Steve Ravet wrote:
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm

From jryan at caminofx.org  Fri Dec  1 12:28:24 2006
From: jryan at caminofx.org (Jared Ryan)
Date: Fri, 1 Dec 2006 12:28:24 -0600 (CST)
Subject: [Gmecm] TBI and EFE
Message-ID: <Pine.LNX.4.63.0612011221320.23705@kingfisher.caminofx.org>

Do TBI engines typically need the EFE ThermAC setup to run smoothly in 
cold weather?

I have an El Camino that has a heat stove on the passenger side, but I 
recently changed to a Camaro air cleaner that puts the snorkel on the 
driver side (this fits MUCH better with my Camaro serpentine belt setup). 
I will need to put a heat stove on the left-side exhaust manifold in order 
to use the ThermAC.

I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help. 
It made a BIG difference in cold-weather running when I had the QuadraJet 
carburetor, and TBI is also a wet-manifold system.

The reason I ask is that the temperature has dropped into the 30s F, which 
is cold for Houston, TX, and the idle is a little rough.  However, the 
cold weather moved in on the same day I removed and cleaned the IAC valve. 
It is entirely possible I just need to reset the minimum-air setting and 
the idle will smooth out.

Off-idle performance has been perfect, just a little bit of a rough idle 
since it turned cold.  I will do the IAC reset this afternoon, but I still 
wonder if making the ThermAC operational will help a lot.

I notice that the TBI intake manifolds no longer have the exhaust 
crossover under the carburetor/throttle body mounting pad.

I hear a lot about ThermAC, like "It only closes in *really* cold weather. 
When I had it set up properly with the QuadraJet, it would close at least 
a little bit on sunny warm spring days!  It would open quickly, but it 
didn't only work on very cold days, for sure.  On very cold days, like 
what we have here, it often wouldn't ever open completely.


From dunvegan at sbcglobal.net  Fri Dec  1 12:49:49 2006
From: dunvegan at sbcglobal.net (Rick McLeod)
Date: Fri, 1 Dec 2006 10:49:49 -0800 (PST)
Subject: [Gmecm] TBI and EFE
Message-ID: <20061201184949.65883.qmail@web80507.mail.yahoo.com>

J, even on my TPI's that are a 'dry' manifold, there is a TB pre-heat w/ a water passage bypass from the cooling system, I disconnect it in summer, but it makes a big difference in city drivability if not connected in winter!

I'd recommend having it, maybe you remember the old VW's w/ the carb preheat tubes from the past, they had a weighted flap that could be 'locked' open in summer, but the owners manual recommended not doing that 9 months out of the year, yes the cold/cool ones, I've seen ICE form on the carby in them!

Humid cool cliamate, like Houston when temp dips, I'll bet you're icing up a little, doesn't take much!


----- Original Message ----
From: Jared Ryan <jryan at caminofx.org>
To: gmecm at diy-efi.org
Sent: Friday, December 1, 2006 12:28:24 PM
Subject: [Gmecm] TBI and EFE


Do TBI engines typically need the EFE ThermAC setup to run smoothly in 
cold weather?

I have an El Camino that has a heat stove on the passenger side, but I 
recently changed to a Camaro air cleaner that puts the snorkel on the 
driver side (this fits MUCH better with my Camaro serpentine belt setup). 
I will need to put a heat stove on the left-side exhaust manifold in order 
to use the ThermAC.

I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help. 
It made a BIG difference in cold-weather running when I had the QuadraJet 
carburetor, and TBI is also a wet-manifold system.

The reason I ask is that the temperature has dropped into the 30s F, which 
is cold for Houston, TX, and the idle is a little rough.  However, the 
cold weather moved in on the same day I removed and cleaned the IAC valve. 
It is entirely possible I just need to reset the minimum-air setting and 
the idle will smooth out.

Off-idle performance has been perfect, just a little bit of a rough idle 
since it turned cold.  I will do the IAC reset this afternoon, but I still 
wonder if making the ThermAC operational will help a lot.

I notice that the TBI intake manifolds no longer have the exhaust 
crossover under the carburetor/throttle body mounting pad.

I hear a lot about ThermAC, like "It only closes in *really* cold weather. 
When I had it set up properly with the QuadraJet, it would close at least 
a little bit on sunny warm spring days!  It would open quickly, but it 
didn't only work on very cold days, for sure.  On very cold days, like 
what we have here, it often wouldn't ever open completely.
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm

From jryan at caminofx.org  Fri Dec  1 13:06:42 2006
From: jryan at caminofx.org (Jared Ryan)
Date: Fri, 1 Dec 2006 13:06:42 -0600 (CST)
Subject: [Gmecm] TBI and EFE
In-Reply-To: <20061201184949.65883.qmail@web80507.mail.yahoo.com>
References: <20061201184949.65883.qmail@web80507.mail.yahoo.com>
Message-ID: <Pine.LNX.4.63.0612011303060.23785@kingfisher.caminofx.org>

I've never actually seen a carburetor ice, but I don't doubt that it can 
happen.  It just doesn't freeze that often here - but it would only take 
once to cause a problem for me.

This is going to be my project this weekend.  The temperature is flirting 
dangerously with freezing in the early mornings.  Thankfully, the 
relatively humidity is low for once.

On Fri, 1 Dec 2006, Rick McLeod wrote:

> J, even on my TPI's that are a 'dry' manifold, there is a TB pre-heat w/ a water passage bypass from the cooling system, I disconnect it in summer, but it makes a big difference in city drivability if not connected in winter!

I'd recommend having it, maybe you remember the old VW's w/ the carb preheat tubes from the past, they had a weighted flap that could be 'locked' open in summer, but the owners manual recommended not doing that 9 months out of the year, yes the cold/cool ones, I've seen ICE form on the carby in them!

Humid cool cliamate, like Houston when temp dips, I'll bet you're icing up a little, doesn't take much!


----- Original Message ----
From: Jared Ryan <jryan at caminofx.org>
To: gmecm at diy-efi.org
Sent: Friday, December 1, 2006 12:28:24 PM
Subject: [Gmecm] TBI and EFE


Do TBI engines typically need the EFE ThermAC setup to run smoothly in 
cold weather?

I have an El Camino that has a heat stove on the passenger side, but I 
recently changed to a Camaro air cleaner that puts the snorkel on the 
driver side (this fits MUCH better with my Camaro serpentine belt setup). 
I will need to put a heat stove on the left-side exhaust manifold in order 
to use the ThermAC.

I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help. 
It made a BIG difference in cold-weather running when I had the QuadraJet 
carburetor, and TBI is also a wet-manifold system.

The reason I ask is that the temperature has dropped into the 30s F, which 
is cold for Houston, TX, and the idle is a little rough.  However, the 
cold weather moved in on the same day I removed and cleaned the IAC valve. 
It is entirely possible I just need to reset the minimum-air setting and 
the idle will smooth out.

Off-idle performance has been perfect, just a little bit of a rough idle 
since it turned cold.  I will do the IAC reset this afternoon, but I still 
wonder if making the ThermAC operational will help a lot.

I notice that the TBI intake manifolds no longer have the exhaust 
crossover under the carburetor/throttle body mounting pad.

I hear a lot about ThermAC, like "It only closes in *really* cold weather. 
When I had it set up properly with the QuadraJet, it would close at least 
a little bit on sunny warm spring days!  It would open quickly, but it 
didn't only work on very cold days, for sure.  On very cold days, like 
what we have here, it often wouldn't ever open completely.
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>


From jryan at caminofx.org  Fri Dec  1 13:42:01 2006
From: jryan at caminofx.org (Jared Ryan)
Date: Fri, 1 Dec 2006 13:42:01 -0600 (CST)
Subject: [Gmecm] TBI and EFE
In-Reply-To: <20061201184949.65883.qmail@web80507.mail.yahoo.com>
References: <20061201184949.65883.qmail@web80507.mail.yahoo.com>
Message-ID: <Pine.LNX.4.63.0612011340320.23840@kingfisher.caminofx.org>

I just did a little reading on carburetor icing - perhaps it is happening 
a little bit, even though the ambient air is above freezing.  Hmmm.

I notice that it starts instantly cold and runs pretty well overall.  It's 
just a rough idle when it has warmed up that is bothering me.

On Fri, 1 Dec 2006, Rick McLeod wrote:

> J, even on my TPI's that are a 'dry' manifold, there is a TB pre-heat w/ a water passage bypass from the cooling system, I disconnect it in summer, but it makes a big difference in city drivability if not connected in winter!

I'd recommend having it, maybe you remember the old VW's w/ the carb preheat tubes from the past, they had a weighted flap that could be 'locked' open in summer, but the owners manual recommended not doing that 9 months out of the year, yes the cold/cool ones, I've seen ICE form on the carby in them!

Humid cool cliamate, like Houston when temp dips, I'll bet you're icing up a little, doesn't take much!


----- Original Message ----
From: Jared Ryan <jryan at caminofx.org>
To: gmecm at diy-efi.org
Sent: Friday, December 1, 2006 12:28:24 PM
Subject: [Gmecm] TBI and EFE


Do TBI engines typically need the EFE ThermAC setup to run smoothly in 
cold weather?

I have an El Camino that has a heat stove on the passenger side, but I 
recently changed to a Camaro air cleaner that puts the snorkel on the 
driver side (this fits MUCH better with my Camaro serpentine belt setup). 
I will need to put a heat stove on the left-side exhaust manifold in order 
to use the ThermAC.

I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help. 
It made a BIG difference in cold-weather running when I had the QuadraJet 
carburetor, and TBI is also a wet-manifold system.

The reason I ask is that the temperature has dropped into the 30s F, which 
is cold for Houston, TX, and the idle is a little rough.  However, the 
cold weather moved in on the same day I removed and cleaned the IAC valve. 
It is entirely possible I just need to reset the minimum-air setting and 
the idle will smooth out.

Off-idle performance has been perfect, just a little bit of a rough idle 
since it turned cold.  I will do the IAC reset this afternoon, but I still 
wonder if making the ThermAC operational will help a lot.

I notice that the TBI intake manifolds no longer have the exhaust 
crossover under the carburetor/throttle body mounting pad.

I hear a lot about ThermAC, like "It only closes in *really* cold weather. 
When I had it set up properly with the QuadraJet, it would close at least 
a little bit on sunny warm spring days!  It would open quickly, but it 
didn't only work on very cold days, for sure.  On very cold days, like 
what we have here, it often wouldn't ever open completely.
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>


From Terminal_Crazy at sand-hill.freeserve.co.uk  Fri Dec  1 14:04:47 2006
From: Terminal_Crazy at sand-hill.freeserve.co.uk (Terminal Crazy)
Date: Fri, 01 Dec 2006 20:04:47 +0000 (GMT)
Subject: [Gmecm] TBI and EFE
In-Reply-To: <Pine.LNX.4.63.0612011340320.23840@kingfisher.caminofx.org>
References: <20061201184949.65883.qmail@web80507.mail.yahoo.com>
	<Pine.LNX.4.63.0612011340320.23840@kingfisher.caminofx.org>
Message-ID: <4e8e8fa97cTerminal_Crazy@sand-hill.freeserve.co.uk>

On 01 Dec, Jared Ryan <jryan at caminofx.org> wrote:
> I just did a little reading on carburetor icing - perhaps it is
> happening a little bit, even though the ambient air is above freezing. 
> Hmmm.

> I notice that it starts instantly cold and runs pretty well overall. 
> It's  just a rough idle when it has warmed up that is bothering me.

My '78 305 & 350 had a Holley 600cfm with the choke mechanism removed and a
aluminium street scoop. In cold damp weather, it would idle / drive rough
if driven straight away for upto 20 minutes or so. Letting it idle for 3/4
minutes then stopping it for a  minute always made it run sweet. I always
attributed this to carb icing but never actually knew if this for sure.

-- 
Mitch - 1995 Z28 LT1 M6          terminal_crazy at sand-hill.freeserve.co.uk
Lancashire England          http://www.sand-hill.freeserve.co.uk/terminal_crazy/



From jryan at caminofx.org  Fri Dec  1 14:23:35 2006
From: jryan at caminofx.org (Jared Ryan)
Date: Fri, 1 Dec 2006 14:23:35 -0600 (CST)
Subject: [Gmecm] TBI and EFE
In-Reply-To: <4e8e8fa97cTerminal_Crazy@sand-hill.freeserve.co.uk>
References: <20061201184949.65883.qmail@web80507.mail.yahoo.com>
	<Pine.LNX.4.63.0612011340320.23840@kingfisher.caminofx.org>
	<4e8e8fa97cTerminal_Crazy@sand-hill.freeserve.co.uk>
Message-ID: <Pine.LNX.4.63.0612011418100.23911@kingfisher.caminofx.org>

It still idles rough after driving at 65 mph for 30 miles.  It is, 
however, sucking in air from right behind the driver-side headlight, so 
the intake air is effectively at ambient temperature.  It isn't getting 
the benefit of intake air heated by the radiator.

I am using a 195-degree thermostat, incidentally.  The ECM is a 1228746 
with an unmodified '89 9C1 Caprice 350 chip.

I'll see if resetting the minimum air helps any, but after your response 
and Rick's I bet I need that heat stove to make it run sweet.

On Fri, 1 Dec 2006, Terminal Crazy wrote:

> On 01 Dec, Jared Ryan <jryan at caminofx.org> wrote:
>> I just did a little reading on carburetor icing - perhaps it is
>> happening a little bit, even though the ambient air is above freezing.
>> Hmmm.
>
>> I notice that it starts instantly cold and runs pretty well overall.
>> It's  just a rough idle when it has warmed up that is bothering me.
>
> My '78 305 & 350 had a Holley 600cfm with the choke mechanism removed and a
> aluminium street scoop. In cold damp weather, it would idle / drive rough
> if driven straight away for upto 20 minutes or so. Letting it idle for 3/4
> minutes then stopping it for a  minute always made it run sweet. I always
> attributed this to carb icing but never actually knew if this for sure.
>
> -- 
> Mitch - 1995 Z28 LT1 M6          terminal_crazy at sand-hill.freeserve.co.uk
> Lancashire England          http://www.sand-hill.freeserve.co.uk/terminal_crazy/
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>


From Steve.Ravet at arm.com  Fri Dec  1 16:43:15 2006
From: Steve.Ravet at arm.com (Steve Ravet)
Date: Fri, 1 Dec 2006 16:43:15 -0600
Subject: [Gmecm] Re: Gmecm Digest, Vol 22, Issue 1
Message-ID: <DBB2E4C4173F1749B6C743414061178301795079@NASDAQ.usa.Arm.com>

 

> -----Original Message-----
> From: gmecm-bounces at diy-efi.org 
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of William Lucke
> Sent: Friday, December 01, 2006 11:31 AM
> To: gmecm at diy-efi.org
> Subject: [Gmecm] Re: Gmecm Digest, Vol 22, Issue 1
> 
> Dual use coolant sensor info: 
> http://theherd.com/articles/lt4_temp.html
> (single sensor for both gauge and ECM)
> 

Forgot about that, but it reminds me that vortec pickups ('96-'99, and
probably ever since then) use an all-in-one oil pressure sender with
both switch and analog output.

--steve



From lwester at lincsat.com  Fri Dec  1 17:54:07 2006
From: lwester at lincsat.com (Programmer)
Date: Fri, 1 Dec 2006 16:54:07 -0700
Subject: [Gmecm] TBI and EFE
References: <20061201184949.65883.qmail@web80507.mail.yahoo.com>
	<Pine.LNX.4.63.0612011303060.23785@kingfisher.caminofx.org>
Message-ID: <004601c715a4$02578b20$0200a8c0@WESTER2>

For icing--all you need is the correct pressure drop across the throttle 
plates and humidity levels that contribute.
I've seen idling TBI trucks with frost on the blades at 48F.

Lyndon. (Canuckian)...

----- Original Message ----- 
From: "Jared Ryan" <jryan at caminofx.org>
To: <gmecm at diy-efi.org>
Sent: Friday, December 01, 2006 12:06 PM
Subject: Re: [Gmecm] TBI and EFE


> I've never actually seen a carburetor ice, but I don't doubt that it can 
> happen.  It just doesn't freeze that often here - but it would only take 
> once to cause a problem for me.
>
> This is going to be my project this weekend.  The temperature is flirting 
> dangerously with freezing in the early mornings.  Thankfully, the 
> relatively humidity is low for once.
>
> On Fri, 1 Dec 2006, Rick McLeod wrote:
>
>> J, even on my TPI's that are a 'dry' manifold, there is a TB pre-heat w/ 
>> a water passage bypass from the cooling system, I disconnect it in 
>> summer, but it makes a big difference in city drivability if not 
>> connected in winter!
>
> I'd recommend having it, maybe you remember the old VW's w/ the carb 
> preheat tubes from the past, they had a weighted flap that could be 
> 'locked' open in summer, but the owners manual recommended not doing that 
> 9 months out of the year, yes the cold/cool ones, I've seen ICE form on 
> the carby in them!
>
> Humid cool cliamate, like Houston when temp dips, I'll bet you're icing up 
> a little, doesn't take much!
>
>
> ----- Original Message ----
> From: Jared Ryan <jryan at caminofx.org>
> To: gmecm at diy-efi.org
> Sent: Friday, December 1, 2006 12:28:24 PM
> Subject: [Gmecm] TBI and EFE
>
>
> Do TBI engines typically need the EFE ThermAC setup to run smoothly in 
> cold weather?
>
> I have an El Camino that has a heat stove on the passenger side, but I 
> recently changed to a Camaro air cleaner that puts the snorkel on the 
> driver side (this fits MUCH better with my Camaro serpentine belt setup). 
> I will need to put a heat stove on the left-side exhaust manifold in order 
> to use the ThermAC.
>
> I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help. 
> It made a BIG difference in cold-weather running when I had the QuadraJet 
> carburetor, and TBI is also a wet-manifold system.
>
> The reason I ask is that the temperature has dropped into the 30s F, which 
> is cold for Houston, TX, and the idle is a little rough.  However, the 
> cold weather moved in on the same day I removed and cleaned the IAC valve. 
> It is entirely possible I just need to reset the minimum-air setting and 
> the idle will smooth out.
>
> Off-idle performance has been perfect, just a little bit of a rough idle 
> since it turned cold.  I will do the IAC reset this afternoon, but I still 
> wonder if making the ThermAC operational will help a lot.
>
> I notice that the TBI intake manifolds no longer have the exhaust 
> crossover under the carburetor/throttle body mounting pad.
>
> I hear a lot about ThermAC, like "It only closes in *really* cold weather. 
> When I had it set up properly with the QuadraJet, it would close at least 
> a little bit on sunny warm spring days!  It would open quickly, but it 
> didn't only work on very cold days, for sure.  On very cold days, like 
> what we have here, it often wouldn't ever open completely.
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm 



From davida1 at hiwaay.net  Fri Dec  1 18:13:54 2006
From: davida1 at hiwaay.net (David Allen)
Date: Fri, 1 Dec 2006 18:13:54 -0600
Subject: [Gmecm] TBI and EFE
References: <Pine.LNX.4.63.0612011221320.23705@kingfisher.caminofx.org>
Message-ID: <00d401c715a6$c293a980$91c8a5a6@yancey.com>

  Made absolutely no noticable difference on my TBI-equipped 305.  Re-designing the snorkel to have a larger inlet, and switching to a taller A/F element made a great improvement in high RPM power.  The idling and starting was uneffected.
  Car has been run in Minnesota in February without problems.  The ECM has an air temp sensor in the air box and it seems to do quite well at compensating for the cold-air intake.
   Good luck,
David



----- Original Message ----- 
From: "Jared Ryan" <jryan at caminofx.org>
To: <gmecm at diy-efi.org>
Sent: Friday, December 01, 2006 12:28 PM
Subject: [Gmecm] TBI and EFE


> Do TBI engines typically need the EFE ThermAC setup to run smoothly in 
> cold weather?
> 
> I have an El Camino that has a heat stove on the passenger side, but I 
> recently changed to a Camaro air cleaner that puts the snorkel on the 
> driver side (this fits MUCH better with my Camaro serpentine belt setup). 
> I will need to put a heat stove on the left-side exhaust manifold in order 
> to use the ThermAC.
> 
> I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help. 
> It made a BIG difference in cold-weather running when I had the QuadraJet 
> carburetor, and TBI is also a wet-manifold system.
> 
> The reason I ask is that the temperature has dropped into the 30s F, which 
> is cold for Houston, TX, and the idle is a little rough.  However, the 
> cold weather moved in on the same day I removed and cleaned the IAC valve. 
> It is entirely possible I just need to reset the minimum-air setting and 
> the idle will smooth out.
> 
> Off-idle performance has been perfect, just a little bit of a rough idle 
> since it turned cold.  I will do the IAC reset this afternoon, but I still 
> wonder if making the ThermAC operational will help a lot.
> 
> I notice that the TBI intake manifolds no longer have the exhaust 
> crossover under the carburetor/throttle body mounting pad.
> 
> I hear a lot about ThermAC, like "It only closes in *really* cold weather. 
> When I had it set up properly with the QuadraJet, it would close at least 
> a little bit on sunny warm spring days!  It would open quickly, but it 
> didn't only work on very cold days, for sure.  On very cold days, like 
> what we have here, it often wouldn't ever open completely.
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>


From bcroe at juno.com  Fri Dec  1 19:30:08 2006
From: bcroe at juno.com (bcroe at juno.com)
Date: Fri, 1 Dec 2006 19:30:08 -0600
Subject: [Gmecm] Gmecm Digest, Vol 22, Issue 1
Message-ID: <20061201.193416.1144.1.bcroe@juno.com>

I used a spare amplifier in my 79 ECU to drive a temp 
gauge.  But it was messy to hook up, gauge didn't work 
when I was switching ECUs.  Probably not a great idea.

Bruce Roe

1 Dec 2006 William Lucke <william.lucke at highspeedlink.net> writes:
> Dual use coolant sensor info: 
> http://theherd.com/articles/lt4_temp.html
> (single sensor for both gauge and ECM)

> Will

> > Date: 30 Nov 06 
> > From: Jared Ryan <jryan at caminofx.org>
> > Subject: RE: [Gmecm] TBI conversion
> > To: gmecm at diy-efi.org
> > Message-ID:
> > 
> 	<Pine.LNX.4.63.0611301211550.21658 at kingfisher.caminofx.org>
> > Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
> > 
> > A Chevy V-8 has two coolant sensors.  There is one on 
> > the intake manifold, in or near the thermostat housing.  
> > That is for the ECM.  There is another one in the driver-side 
> > cylinder head.  That is for the gauge in the 
> > dashboard.  They are totally separate.


From clare at snyder.on.ca  Fri Dec  1 21:39:13 2006
From: clare at snyder.on.ca (Clare Snyder)
Date: Fri, 1 Dec 2006 22:39:13 -0500
Subject: Subject: Re: [Gmecm] TBI and EFE
Message-ID: <001301c715c3$6fcab4b0$6901a8c0@snyderxp>

> Message: 2
> Date: Fri, 1 Dec 2006 10:49:49 -0800 (PST)
> From: Rick McLeod <dunvegan at sbcglobal.net>
> Subject: Re: [Gmecm] TBI and EFE
> To: gmecm at diy-efi.org
> Message-ID: <20061201184949.65883.qmail at web80507.mail.yahoo.com>
> Content-Type: text/plain; charset=ascii
>
> J, even on my TPI's that are a 'dry' manifold, there is a TB pre-heat w/ a 
> water passage bypass from the cooling system, I disconnect it in summer, 
> but it makes a big difference in city drivability if not connected in 
> winter!
>
> I'd recommend having it, maybe you remember the old VW's w/ the carb 
> preheat tubes from the past, they had a weighted flap that could be 
> 'locked' open in summer, but the owners manual recommended not doing that 
> 9 months out of the year, yes the cold/cool ones, I've seen ICE form on 
> the carby in them!

I used to drive a 1949 VW in Zambia, Central Africa - and I would on 
occaision even get carb ice THERE at 5500 feet ASL. Carb ice and vapour lock 
on the same day!!! 



From davesnothereman at netscape.net  Sat Dec  2 09:31:42 2006
From: davesnothereman at netscape.net (davesnothereman at netscape.net)
Date: Sat, 02 Dec 2006 10:31:42 -0500
Subject: [Gmecm] TBI and EFE
In-Reply-To: <Pine.LNX.4.63.0612011221320.23705@kingfisher.caminofx.org>
References: <Pine.LNX.4.63.0612011221320.23705@kingfisher.caminofx.org>
Message-ID: <8C8E43E1A413AB3-F94-2BA6@MBLK-M16.sysops.aol.com>

 
 The TBI trucks w/ 7747 expect intake air temp around 90 deg F or greater.  The intake air heater is calibrated for this temp.  Most folks with older tbi trucks don't seem to know / care.  In an area where 10 year old trucks are rotted out due to salt, snow, and humidity it's not uncommon to see the few left running with no heat stove left on the manifold and no tube connected to the snorkel.
 
The question you need to answer is "How good is good enough?"  I have open element air cleaners on my truck which used to run in temps well below zero without causing any issues which I can remember.
 
The old carby 2.8 S10's had an electrically heated grid under the carb to prevent icing.  A 15-20 mile drive at highway speed at 50 deg temps could cause enough restriction to bring vehicle speed below 30 mph if the heater was inoperative.
 
Zaphod
 
-----Original Message-----
From: jryan at caminofx.org
To: gmecm at diy-efi.org
Sent: Fri, 1 Dec 2006 1:28 PM
Subject: [Gmecm] TBI and EFE


Do TBI engines typically need the EFE ThermAC setup to run smoothly in cold weather? 
 
I have an El Camino that has a heat stove on the passenger side, but I recently changed to a Camaro air cleaner that puts the snorkel on the driver side (this fits MUCH better with my Camaro serpentine belt setup). I will need to put a heat stove on the left-side exhaust manifold in order to use the ThermAC. 
 
I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help. It made a BIG difference in cold-weather running when I had the QuadraJet carburetor, and TBI is also a wet-manifold system. 
 
The reason I ask is that the temperature has dropped into the 30s F, which is cold for Houston, TX, and the idle is a little rough. However, the cold weather moved in on the same day I removed and cleaned the IAC valve. It is entirely possible I just need to reset the minimum-air setting and the idle will smooth out. 
 
Off-idle performance has been perfect, just a little bit of a rough idle since it turned cold. I will do the IAC reset this afternoon, but I still wonder if making the ThermAC operational will help a lot. 
 
I notice that the TBI intake manifolds no longer have the exhaust crossover under the carburetor/throttle body mounting pad. 
 
I hear a lot about ThermAC, like "It only closes in *really* cold weather. When I had it set up properly with the QuadraJet, it would close at least a little bit on sunny warm spring days! It would open quickly, but it didn't only work on very cold days, for sure. On very cold days, like what we have here, it often wouldn't ever open completely. 
_______________________________________________ 
Gmecm mailing list 
Gmecm at diy-efi.org 
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm 
Main WWW page: http://www.diy-efi.org/gmecm 
________________________________________________________________________
Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading spam and email virus protection.


From davesnothereman at netscape.net  Sat Dec  2 09:38:00 2006
From: davesnothereman at netscape.net (davesnothereman at netscape.net)
Date: Sat, 02 Dec 2006 10:38:00 -0500
Subject: [Gmecm] TBI conversion
In-Reply-To: <20061130.225005.280.0.bcroe@juno.com>
References: <20061130.225005.280.0.bcroe@juno.com>
Message-ID: <8C8E43EFB487792-F94-2BD0@MBLK-M16.sysops.aol.com>

 
 
 
-----Original Message-----
From: bcroe at juno.com
To: gmecm at diy-efi.org
Sent: Thu, 30 Nov 2006 11:09 PM
Subject: [Gmecm] TBI conversion


My understanding is EFI cars have true MAP sensors, but 
CCC engines have a sensor referenced to air pressure (as 
opposed to absolute zero pressure), is that right?  

Bruce Roe

I don't believe this is universally true across all carbureted vehicles.  It's been a few years since I needed to remember Carby Car details, but I believe later CCC vehicles moved toward MAP sensors.
________________________________________________________________________
Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading spam and email virus protection.


From jay at vessels-clan.com  Sat Dec  2 10:00:11 2006
From: jay at vessels-clan.com (Jay Vessels)
Date: Sat, 02 Dec 2006 11:00:11 -0500
Subject: [Gmecm] TBI and EFE
In-Reply-To: <8C8E43E1A413AB3-F94-2BA6@MBLK-M16.sysops.aol.com>
References: <Pine.LNX.4.63.0612011221320.23705@kingfisher.caminofx.org>
	<8C8E43E1A413AB3-F94-2BA6@MBLK-M16.sysops.aol.com>
Message-ID: <4571A30B.5020501@vessels-clan.com>

Hi there!

> The question you need to answer is "How good is good enough?"  I have
> open element air cleaners on my truck which used to run in temps well
> below zero without causing any issues which I can remember.

I've got an open element air cleaner on my S-10 (2.8V6 TBI) and while it 
doesn't get driven much in the wintertime, I don't remember any issues 
with icing.  I'm not saying that it didn't happen but it didn't seem to 
cause any problems.  I also tend to be gentle to cold engines, so maybe 
I've just never demanded more from it than it could take.

The two biggest reasons I've got an open element, though, are because at 
the time it was easier to get than the stock air cleaner, and I was much 
younger and wanted the look ;)

It seems like a better choice is a heat stove + ducting to cold air from 
elsewhere.  That seems like it would give good cold weather performance 
and still let it run decently when icing isn't an issue.  Come to think 
of it, that's exactly what GM did... :)

I don't remember what Cadillac did exactly, but if I remember right my 
'89 Eldorado (4.5V8 DFI -- a TBI system with a different name) didn't 
have a heat stove.  It had a "hat" and ducting that ducted air from a 
remote air cleaner box to the TBI.  I don't remember a heat stove in 
that system.

> The old carby 2.8 S10's had an electrically heated grid under the
> carb to prevent icing.

Yup -- they had a heat stove, too, and ducting from the radiator support 
to the air cleaner.  The 2.8 V6 TBI setup had a heat stove but not EFE. 
  The intake manifold on those trucks has the heater hose dumping water 
into the intake immediately under the TBI mounting pad.  Not so good for 
keeping the air charge cold for power, but I'm sure it does a good job 
of keeping the TBI warmed up for cold weather driving.

Jay Vessels
1982 Chevrolet S-10 Sport, 2.8V6 TBI
1984 Chevrolet S-10 Blazer Sport, 2.8V6 (TBI pending)


From jay at vessels-clan.com  Sat Dec  2 10:05:56 2006
From: jay at vessels-clan.com (Jay Vessels)
Date: Sat, 02 Dec 2006 11:05:56 -0500
Subject: [Gmecm] TBI conversion
In-Reply-To: <8C8E43EFB487792-F94-2BD0@MBLK-M16.sysops.aol.com>
References: <20061130.225005.280.0.bcroe@juno.com>
	<8C8E43EFB487792-F94-2BD0@MBLK-M16.sysops.aol.com>
Message-ID: <4571A464.1010103@vessels-clan.com>

Hi there!

I *think* I've seen later model CCC cars ('86 Caprice 305 Q-jet
specifically) that had *both* but it's been 10 years since I looked at
one so I can't say for sure. I could easily be misremembering that.

I have never seen a GM EFI engine with a BARO sensor (a MAP sensor 
referenced to atmosphere). I can't say with certainty of course but I'd 
bet money all GM EFI systems starting in the '80s all have MAP sensors 
if they have anything at all.

Jay Vessels
1982 Chevrolet S-10 Sport, 2.8V6 TBI
1984 Chevrolet S-10 Blazer Sport, 2.8V6 (TBI pending)

davesnothereman at netscape.net wrote:
> 
> 
> 
> -----Original Message----- From: bcroe at juno.com To: gmecm at diy-efi.org
>  Sent: Thu, 30 Nov 2006 11:09 PM Subject: [Gmecm] TBI conversion
> 
> 
> My understanding is EFI cars have true MAP sensors, but CCC engines 
> have a sensor referenced to air pressure (as opposed to absolute zero
>  pressure), is that right?
> 
> Bruce Roe
> 
> I don't believe this is universally true across all carbureted 
> vehicles.  It's been a few years since I needed to remember Carby Car
>  details, but I believe later CCC vehicles moved toward MAP sensors.



From charles at taildragger.info  Sat Dec  2 11:11:49 2006
From: charles at taildragger.info (Charles McDowell)
Date: Sat, 2 Dec 2006 11:11:49 -0600
Subject: [Gmecm] TBI and EFE
In-Reply-To: <Pine.LNX.4.63.0612011340320.23840@kingfisher.caminofx.org>
Message-ID: <mailman.44.1191376416.4273.gmecm@diy-efi.org>

I definitely had carb ice on my old Edelbrock carb.  It doesn't need to be
below freezing, since the fast moving air in the carb makes it colder.  It
was worst for me around 35-40 degrees when it was very humid.  I could see
the frost on the butterflies choking it off at idle.  I had an open element.
There's a reason the factory pumped heat into the intake. 

-----Original Message-----
From: gmecm-bounces at diy-efi.org [mailto:gmecm-bounces at diy-efi.org] On Behalf
Of Jared Ryan
Sent: Friday, December 01, 2006 1:42 PM
To: gmecm at diy-efi.org
Subject: Re: [Gmecm] TBI and EFE

I just did a little reading on carburetor icing - perhaps it is happening a
little bit, even though the ambient air is above freezing.  Hmmm.

I notice that it starts instantly cold and runs pretty well overall.  It's
just a rough idle when it has warmed up that is bothering me.

On Fri, 1 Dec 2006, Rick McLeod wrote:

> J, even on my TPI's that are a 'dry' manifold, there is a TB pre-heat w/ a
water passage bypass from the cooling system, I disconnect it in summer, but
it makes a big difference in city drivability if not connected in winter!

I'd recommend having it, maybe you remember the old VW's w/ the carb preheat
tubes from the past, they had a weighted flap that could be 'locked' open in
summer, but the owners manual recommended not doing that 9 months out of the
year, yes the cold/cool ones, I've seen ICE form on the carby in them!

Humid cool cliamate, like Houston when temp dips, I'll bet you're icing up a
little, doesn't take much!


----- Original Message ----
From: Jared Ryan <jryan at caminofx.org>
To: gmecm at diy-efi.org
Sent: Friday, December 1, 2006 12:28:24 PM
Subject: [Gmecm] TBI and EFE


Do TBI engines typically need the EFE ThermAC setup to run smoothly in cold
weather?

I have an El Camino that has a heat stove on the passenger side, but I
recently changed to a Camaro air cleaner that puts the snorkel on the driver
side (this fits MUCH better with my Camaro serpentine belt setup). 
I will need to put a heat stove on the left-side exhaust manifold in order
to use the ThermAC.

I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help. 
It made a BIG difference in cold-weather running when I had the QuadraJet
carburetor, and TBI is also a wet-manifold system.

The reason I ask is that the temperature has dropped into the 30s F, which
is cold for Houston, TX, and the idle is a little rough.  However, the cold
weather moved in on the same day I removed and cleaned the IAC valve. 
It is entirely possible I just need to reset the minimum-air setting and the
idle will smooth out.

Off-idle performance has been perfect, just a little bit of a rough idle
since it turned cold.  I will do the IAC reset this afternoon, but I still
wonder if making the ThermAC operational will help a lot.

I notice that the TBI intake manifolds no longer have the exhaust crossover
under the carburetor/throttle body mounting pad.

I hear a lot about ThermAC, like "It only closes in *really* cold weather. 
When I had it set up properly with the QuadraJet, it would close at least a
little bit on sunny warm spring days!  It would open quickly, but it didn't
only work on very cold days, for sure.  On very cold days, like what we have
here, it often wouldn't ever open completely.
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm




From Terminal_Crazy at sand-hill.freeserve.co.uk  Sat Dec  2 02:44:44 2006
From: Terminal_Crazy at sand-hill.freeserve.co.uk (Terminal Crazy)
Date: Sat, 02 Dec 2006 08:44:44 +0000 (GMT)
Subject: [Gmecm] TBI and EFE
In-Reply-To: <Pine.LNX.4.63.0612011418100.23911@kingfisher.caminofx.org>
References: <20061201184949.65883.qmail@web80507.mail.yahoo.com>
	<Pine.LNX.4.63.0612011340320.23840@kingfisher.caminofx.org>
	<4e8e8fa97cTerminal_Crazy@sand-hill.freeserve.co.uk>
	<Pine.LNX.4.63.0612011418100.23911@kingfisher.caminofx.org>
Message-ID: <4e8ed53c72Terminal_Crazy@sand-hill.freeserve.co.uk>

On 01 Dec, Jared Ryan <jryan at caminofx.org> wrote:
> It still idles rough after driving at 65 mph for 30 miles.  It is, 
> however, sucking in air from right behind the driver-side headlight, so 
> the intake air is effectively at ambient temperature.  It isn't getting 
> the benefit of intake air heated by the radiator.

> I am using a 195-degree thermostat, incidentally.  The ECM is a 1228746 
> with an unmodified '89 9C1 Caprice 350 chip.

> I'll see if resetting the minimum air helps any, but after your response 
> and Rick's I bet I need that heat stove to make it run sweet.

Just try stopping the motor for 30 seconds or so after a short run and see
if it allows any heat to transfer. It always cleared up. It was also worse
in wet weather rather than just cold presumably due to the higher water
content in the air freezing up the carb.

HTH

-- 
Mitch - 1995 Z28 LT1 M6          terminal_crazy at sand-hill.freeserve.co.uk
Lancashire England          http://www.sand-hill.freeserve.co.uk/terminal_crazy/



From dennysweet at charter.net  Sat Dec  2 17:54:51 2006
From: dennysweet at charter.net (Denny)
Date: Sat, 2 Dec 2006 15:54:51 -0800
Subject: [Gmecm] TBI conversion
References: <20061130.225005.280.0.bcroe@juno.com><8C8E43EFB487792-F94-2BD0@MBLK-M16.sysops.aol.com>
	<4571A464.1010103@vessels-clan.com>
Message-ID: <000d01c7166d$42548470$2e02a8c0@dennyhuyir5nuj>

I know all the TBI units did, Also I beleive that the first port injection 
did on the little 4 cyl. cars



From Rexdina at aol.com  Sat Dec  2 20:09:06 2006
From: Rexdina at aol.com (Rexdina at aol.com)
Date: Sat, 2 Dec 2006 21:09:06 EST
Subject: [Gmecm] Carburetor Icing
Message-ID: <cfa.38a8de0.32a38bc2@aol.com>



From davida1 at hiwaay.net  Sat Dec  2 20:09:27 2006
From: davida1 at hiwaay.net (David Allen)
Date: Sat, 2 Dec 2006 20:09:27 -0600
Subject: [Gmecm] Carburetor Icing
References: <cfa.38a8de0.32a38bc2@aol.com>
Message-ID: <003901c71680$1368f8e0$0600a8c0@yancey.com>

Got a blank message?

----- Original Message ----- 
From: <Rexdina at aol.com>
To: <gmecm at diy-efi.org>
Sent: Saturday, December 02, 2006 8:09 PM
Subject: [Gmecm] Carburetor Icing


> 
>


--------------------------------------------------------------------------------


> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>


From Rexdina at aol.com  Sat Dec  2 20:13:29 2006
From: Rexdina at aol.com (Rexdina at aol.com)
Date: Sat, 2 Dec 2006 21:13:29 EST
Subject: [Gmecm] Carburetor Icing?
Message-ID: <412.f1fe5e0.32a38cc9@aol.com>



From Rexdina at aol.com  Sat Dec  2 20:16:39 2006
From: Rexdina at aol.com (Rexdina at aol.com)
Date: Sat, 2 Dec 2006 21:16:39 EST
Subject: [Gmecm] Carburetor Icing?
Message-ID: <c0f.a78b47f.32a38d87@aol.com>

Let's try this again!


From Rexdina at aol.com  Sat Dec  2 20:19:31 2006
From: Rexdina at aol.com (Rexdina at aol.com)
Date: Sat, 2 Dec 2006 21:19:31 EST
Subject: [Gmecm] Carburetor Icing?
Message-ID: <bda.9467432.32a38e33@aol.com>

I'm going to give up if this one doesn't come  through!


From Rexdina at aol.com  Sat Dec  2 20:23:07 2006
From: Rexdina at aol.com (Rexdina at aol.com)
Date: Sat, 2 Dec 2006 21:23:07 EST
Subject: [Gmecm] Emailing: nowthatscold
Message-ID: <cb7.530697c.32a38f0b@aol.com>

 
In a message dated 12/02/2006 6:04:18 P.M. Pacific Standard Time,  
rexdina at aol.com writes:

The  message is ready to be sent with the following file or link  attachments:
nowthatscold

Note: To protect against computer viruses,  e-mail programs may prevent 
sending or receiving certain types of file  attachments


 

From bcroe at juno.com  Sat Dec  2 20:25:35 2006
From: bcroe at juno.com (bcroe at juno.com)
Date: Sat, 2 Dec 2006 20:25:35 -0600
Subject: [Gmecm] TBI conversion
Message-ID: <20061202.202535.300.0.bcroe@juno.com>

Did what?  

2 Dec 2006  "Denny" <dennysweet at charter.net> writes:
> I know all the TBI units did, Also I beleive that the first port 
> injection did on the little 4 cyl. cars


From jryan at caminofx.org  Sun Dec  3 10:14:58 2006
From: jryan at caminofx.org (Jared Ryan)
Date: Sun, 3 Dec 2006 10:14:58 -0600
Subject: [Gmecm] TBI and EFE
In-Reply-To: <8C8E43E1A413AB3-F94-2BA6@MBLK-M16.sysops.aol.com>
References: <Pine.LNX.4.63.0612011221320.23705@kingfisher.caminofx.org>
	<8C8E43E1A413AB3-F94-2BA6@MBLK-M16.sysops.aol.com>
Message-ID: <dacef7ed167088c85d2cc356ccca722f@caminofx.org>

OK, here is what happened, from the beginning.  The exact sequence is  
important.

I discovered the busted fuel injector O-ring that was the cause of the  
too-rich problems I had been chasing since April.  (The lower O-ring on  
the left-side fuel injector was mashed, letting fuel under pressure  
down into the barrel).  I replaced that, and the engine ran perfectly.   
It idled very slow (at the target idle speed programmed into the ANLU  
chip, about 550 RPM) but very smooth.  Drivability was excellent.

Then, after a few days, I noticed it would sometimes idle faster than  
it had been.  It was still smooth, but about 1000 RPM.  It would flare  
up when I shifted out of drive into Park or Neutral and not come down  
as fast as it had.

All of the preceding is with the daytime highs in the mid-70s and lows  
in the 60s.  Warm weather.

Well, I wondered if the IAC valve might be sticking.  I took out the  
valve and cleaned it.  It wasn't very dirty, hardly any carbon, but I  
sprayed Gum-Out on it and also sprayed it in the passage on the  
throttle body.  I put the IAC valve back in.  I didn't drive it after  
doing this.  Later that night, the arctic blast came through (well, for  
Houston, TX; lows in the low 30s, highs in the 50s at the most).  Since  
the day I cleaned the IAC valve, it has not idled well.  It acts like  
it might be too rich, and it won't idle slower than about 700 RPM.

I've done the IAC reset, grounding the diagnostic pin to force the ECM  
to extend the IAC plunger fully, and the slowest I can get it to idle  
with the IAC valve unplugged is about 600, and it's rough.  It's rough  
with the IAC valve connected, both cold and hot, and it idles faster in  
Park or Neutral than in Drive.  In Drive it's right about at the target  
idle speed, but still rough, but it won't idle down when taken out of  
gear.

By "rough" I mean a bad smell from the tailpipes, car shaking, surging,  
having to really hold my foot on the brake to keep it still at a red  
light due to the surging.

So could I have damaged the IAC valve with the Gum-Out?

I broke the scientific method and changed two things at once (OK, so I  
can't control the weather), and now I don't know if I have an acting-up  
IAC valve, a fuel leak, or if it just doesn't like the chilled air.

The pintle of the IAC valve looks like it could possibly wear over time  
and not seal against the throttle body, with or without carbon buildup.

  ---> Jared Ryan <---
jryan at caminofx.org | http://www.caminofx.org

On Dec 2, 2006, at 9:31 AM, davesnothereman at netscape.net wrote:

>
>  The TBI trucks w/ 7747 expect intake air temp around 90 deg F or  
> greater.  The intake air heater is calibrated for this temp.  Most  
> folks with older tbi trucks don't seem to know / care.  In an area  
> where 10 year old trucks are rotted out due to salt, snow, and  
> humidity it's not uncommon to see the few left running with no heat  
> stove left on the manifold and no tube connected to the snorkel.
>
> The question you need to answer is "How good is good enough?"  I have  
> open element air cleaners on my truck which used to run in temps well  
> below zero without causing any issues which I can remember.
>
> The old carby 2.8 S10's had an electrically heated grid under the carb  
> to prevent icing.  A 15-20 mile drive at highway speed at 50 deg temps  
> could cause enough restriction to bring vehicle speed below 30 mph if  
> the heater was inoperative.
>
> Zaphod
>
> -----Original Message-----
> From: jryan at caminofx.org
> To: gmecm at diy-efi.org
> Sent: Fri, 1 Dec 2006 1:28 PM
> Subject: [Gmecm] TBI and EFE
>
>
> Do TBI engines typically need the EFE ThermAC setup to run smoothly in  
> cold weather?
>
> I have an El Camino that has a heat stove on the passenger side, but I  
> recently changed to a Camaro air cleaner that puts the snorkel on the  
> driver side (this fits MUCH better with my Camaro serpentine belt  
> setup). I will need to put a heat stove on the left-side exhaust  
> manifold in order to use the ThermAC.
>
> I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't  
> help. It made a BIG difference in cold-weather running when I had the  
> QuadraJet carburetor, and TBI is also a wet-manifold system.
>
> The reason I ask is that the temperature has dropped into the 30s F,  
> which is cold for Houston, TX, and the idle is a little rough.  
> However, the cold weather moved in on the same day I removed and  
> cleaned the IAC valve. It is entirely possible I just need to reset  
> the minimum-air setting and the idle will smooth out.
>
> Off-idle performance has been perfect, just a little bit of a rough  
> idle since it turned cold. I will do the IAC reset this afternoon, but  
> I still wonder if making the ThermAC operational will help a lot.
>
> I notice that the TBI intake manifolds no longer have the exhaust  
> crossover under the carburetor/throttle body mounting pad.
>
> I hear a lot about ThermAC, like "It only closes in *really* cold  
> weather. When I had it set up properly with the QuadraJet, it would  
> close at least a little bit on sunny warm spring days! It would open  
> quickly, but it didn't only work on very cold days, for sure. On very  
> cold days, like what we have here, it often wouldn't ever open  
> completely.
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> _______________________________________________________________________ 
> _
> Check Out the new free AIM(R) Mail -- 2 GB of storage and  
> industry-leading spam and email virus protection.
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>



From tl34ru at yahoo.com  Sun Dec  3 11:04:42 2006
From: tl34ru at yahoo.com (terry)
Date: Sun, 3 Dec 2006 09:04:42 -0800 (PST)
Subject: [Gmecm] TBI and EFE
In-Reply-To: <dacef7ed167088c85d2cc356ccca722f@caminofx.org>
Message-ID: <702269.41031.qm@web32501.mail.mud.yahoo.com>

Have you checked for a vacuum leak, how old is the
throttle body gskt.
It sounds like a vacuum leak which would cause the
idle
problem and the smell out the exhaust.
Have you check any engine data?
Terry
--- Jared Ryan <jryan at caminofx.org> wrote:

> OK, here is what happened, from the beginning.  The
> exact sequence is  
> important.
> 
> I discovered the busted fuel injector O-ring that
> was the cause of the  
> too-rich problems I had been chasing since April. 
> (The lower O-ring on  
> the left-side fuel injector was mashed, letting fuel
> under pressure  
> down into the barrel).  I replaced that, and the
> engine ran perfectly.   
> It idled very slow (at the target idle speed
> programmed into the ANLU  
> chip, about 550 RPM) but very smooth.  Drivability
> was excellent.
> 
> Then, after a few days, I noticed it would sometimes
> idle faster than  
> it had been.  It was still smooth, but about 1000
> RPM.  It would flare  
> up when I shifted out of drive into Park or Neutral
> and not come down  
> as fast as it had.
> 
> All of the preceding is with the daytime highs in
> the mid-70s and lows  
> in the 60s.  Warm weather.
> 
> Well, I wondered if the IAC valve might be sticking.
>  I took out the  
> valve and cleaned it.  It wasn't very dirty, hardly
> any carbon, but I  
> sprayed Gum-Out on it and also sprayed it in the
> passage on the  
> throttle body.  I put the IAC valve back in.  I
> didn't drive it after  
> doing this.  Later that night, the arctic blast came
> through (well, for  
> Houston, TX; lows in the low 30s, highs in the 50s
> at the most).  Since  
> the day I cleaned the IAC valve, it has not idled
> well.  It acts like  
> it might be too rich, and it won't idle slower than
> about 700 RPM.
> 
> I've done the IAC reset, grounding the diagnostic
> pin to force the ECM  
> to extend the IAC plunger fully, and the slowest I
> can get it to idle  
> with the IAC valve unplugged is about 600, and it's
> rough.  It's rough  
> with the IAC valve connected, both cold and hot, and
> it idles faster in  
> Park or Neutral than in Drive.  In Drive it's right
> about at the target  
> idle speed, but still rough, but it won't idle down
> when taken out of  
> gear.
> 
> By "rough" I mean a bad smell from the tailpipes,
> car shaking, surging,  
> having to really hold my foot on the brake to keep
> it still at a red  
> light due to the surging.
> 
> So could I have damaged the IAC valve with the
> Gum-Out?
> 
> I broke the scientific method and changed two things
> at once (OK, so I  
> can't control the weather), and now I don't know if
> I have an acting-up  
> IAC valve, a fuel leak, or if it just doesn't like
> the chilled air.
> 
> The pintle of the IAC valve looks like it could
> possibly wear over time  
> and not seal against the throttle body, with or
> without carbon buildup.
> 
>   ---> Jared Ryan <---
> jryan at caminofx.org | http://www.caminofx.org
> 
> On Dec 2, 2006, at 9:31 AM,
> davesnothereman at netscape.net wrote:
> 
> >
> >  The TBI trucks w/ 7747 expect intake air temp
> around 90 deg F or  
> > greater.  The intake air heater is calibrated for
> this temp.  Most  
> > folks with older tbi trucks don't seem to know /
> care.  In an area  
> > where 10 year old trucks are rotted out due to
> salt, snow, and  
> > humidity it's not uncommon to see the few left
> running with no heat  
> > stove left on the manifold and no tube connected
> to the snorkel.
> >
> > The question you need to answer is "How good is
> good enough?"  I have  
> > open element air cleaners on my truck which used
> to run in temps well  
> > below zero without causing any issues which I can
> remember.
> >
> > The old carby 2.8 S10's had an electrically heated
> grid under the carb  
> > to prevent icing.  A 15-20 mile drive at highway
> speed at 50 deg temps  
> > could cause enough restriction to bring vehicle
> speed below 30 mph if  
> > the heater was inoperative.
> >
> > Zaphod
> >
> > -----Original Message-----
> > From: jryan at caminofx.org
> > To: gmecm at diy-efi.org
> > Sent: Fri, 1 Dec 2006 1:28 PM
> > Subject: [Gmecm] TBI and EFE
> >
> >
> > Do TBI engines typically need the EFE ThermAC
> setup to run smoothly in  
> > cold weather?
> >
> > I have an El Camino that has a heat stove on the
> passenger side, but I  
> > recently changed to a Camaro air cleaner that puts
> the snorkel on the  
> > driver side (this fits MUCH better with my Camaro
> serpentine belt  
> > setup). I will need to put a heat stove on the
> left-side exhaust  
> > manifold in order to use the ThermAC.
> >
> > I assume it wouldn't be there (on '88-'92 TBI
> F-bodies) if it didn't  
> > help. It made a BIG difference in cold-weather
> running when I had the  
> > QuadraJet carburetor, and TBI is also a
> wet-manifold system.
> >
> > The reason I ask is that the temperature has
> dropped into the 30s F,  
> > which is cold for Houston, TX, and the idle is a
> little rough.  
> > However, the cold weather moved in on the same day
> I removed and  
> > cleaned the IAC valve. It is entirely possible I
> just need to reset  
> > the minimum-air setting and the idle will smooth
> out.
> >
> > Off-idle performance has been perfect, just a
> little bit of a rough  
> > idle since it turned cold. I will do the IAC reset
> this afternoon, but  
> > I still wonder if making the ThermAC operational
> will help a lot.
> >
> > I notice that the TBI intake manifolds no longer
> have the exhaust  
> > crossover under the carburetor/throttle body
> mounting pad.
> >
> > I hear a lot about ThermAC, like "It only closes
> in *really* cold  
> > weather. When I had it set up properly with the
> QuadraJet, it would  
> > close at least a little bit on sunny warm spring
> days! It would open  
> > quickly, but it didn't only work on very cold
> days, for sure. On very  
> > cold days, like what we have here, it often
> wouldn't ever open  
> > completely.
> > _______________________________________________
> > Gmecm mailing list
> > Gmecm at diy-efi.org
> > Subscribe:
> http://lists.diy-efi.org/mailman/listinfo/gmecm
> > Main WWW page: http://www.diy-efi.org/gmecm
> >
>
_______________________________________________________________________
> 
> > _
> > Check Out the new free AIM(R) Mail -- 2 GB of
> storage and  
> > industry-leading spam and email virus protection.
> > _______________________________________________
> > Gmecm mailing list
> > Gmecm at diy-efi.org
> > Subscribe:
> http://lists.diy-efi.org/mailman/listinfo/gmecm
> > Main WWW page: http://www.diy-efi.org/gmecm
> >
> 
> 
=== message truncated ===



 
____________________________________________________________________________________
Yahoo! Music Unlimited
Access over 1 million songs.
http://music.yahoo.com/unlimited


From dunvegan at sbcglobal.net  Sun Dec  3 11:20:44 2006
From: dunvegan at sbcglobal.net (Rick McLeod)
Date: Sun, 3 Dec 2006 09:20:44 -0800 (PST)
Subject: [Gmecm] TBI and EFE
Message-ID: <20061203172044.63126.qmail@web80505.mail.yahoo.com>

It appears the onset of the 'problem' was coincident w/ the work on the IAC valve. I'd suggest going back to that point and checking the re-assembly to ensure you have'nt compromised that part. Also, is there a base idle setup for the TBI similar to those on TPI, where you bottom out the IAC and then set minimum idle on the butterfly? The purpose of the IAC is not to control minimum idle speed, it's to control thngs like adding when in gear, AC on, and stall prevention when lifting the accel pedal. It's therefore crucial that the mininmum idle be setup correctly w/ the butterfly and the IAC bottomed out, and if there is icing on the butterfly that will affect setting minimum idle, but when running w/ the exception of other issues if the butterfly idle passage gets iced the computer and IAC should compensate by opening IAC to hunt for target idle speed. The surging I suspect is due to minimum idle being set too low or there being a leak somewhere in the idle circuit, or a
 'leaking' injector causing problems.
As for damaging the IAC, I have done what I think you described w/ cleaner on IACs before w/ no ill effects. I'd be more critical of having possibly damaging it by either bending it or getting something in the shaft passage that might have bound it up.
As for the rough idle you refer to, is that w/ the computer disabled from idle control, or with it all buttoned up?
I know my TPIs don't idle really smooth during the setup process, but not to the description you give.
If it is after setup and put back together, I'd have to suggest something else got disturbed during the process that you'd didn't notice.
Since you've worked on all the areas mentioned above, it sounds like going back through all the previously touched areas is in order, making sure everything is clean and not leaking or blocked. Hope this helps, and also hope you've a garage to work in during your artic blast.

BTW, we're about 20*F here in the KC area w/ about 50% humidity overnight, so enjoy your balmy Houston weather! 

Good luck, and btw thanks for the comments on my TBI conversion project, which I'm about 1/2 way through gathering all the goodies for, and your comments have helped steer that effort along.

cheers -rick

From herningg at hotmail.com  Sun Dec  3 18:29:22 2006
From: herningg at hotmail.com (Garrett Herning)
Date: Sun, 03 Dec 2006 19:29:22 -0500
Subject: [Gmecm] TBI and EFE
In-Reply-To: <dacef7ed167088c85d2cc356ccca722f@caminofx.org>
Message-ID: <BAY122-F2635A0BBC1278A148CC446D9DF0@phx.gbl>

You also may want to check the o2 sensor and make sure it still working 
properly after all that excess fuel. I have a wideband controller and sensor 
in my 95 TBI truck (simulating the narrow band signal) and have just run 
across where if the startup voltage is too low for too long on the 
controller, it shuts off and my o2 signal is basically non-exisitant... when 
that happens the ECM will try and adjust to whatever voltage it thinks it 
sees and it will idle all over, surge and loose power as you drive until it 
finally trips a code and goes into open loop. It takes quite a while to 
finally trip a code though....  Just my 2 cents! :)

Garrett Herning



>From: Jared Ryan <jryan at caminofx.org>
>Reply-To: gmecm at diy-efi.org
>To: gmecm at diy-efi.org
>Subject: Re: [Gmecm] TBI and EFE
>Date: Sun, 3 Dec 2006 10:14:58 -0600
>
>OK, here is what happened, from the beginning.  The exact sequence is  
>important.
>
>I discovered the busted fuel injector O-ring that was the cause of the  
>too-rich problems I had been chasing since April.  (The lower O-ring on  
>the left-side fuel injector was mashed, letting fuel under pressure  down 
>into the barrel).  I replaced that, and the engine ran perfectly.   It 
>idled very slow (at the target idle speed programmed into the ANLU  chip, 
>about 550 RPM) but very smooth.  Drivability was excellent.
>
>Then, after a few days, I noticed it would sometimes idle faster than  it 
>had been.  It was still smooth, but about 1000 RPM.  It would flare  up 
>when I shifted out of drive into Park or Neutral and not come down  as fast 
>as it had.
>
>All of the preceding is with the daytime highs in the mid-70s and lows  in 
>the 60s.  Warm weather.
>
>Well, I wondered if the IAC valve might be sticking.  I took out the  valve 
>and cleaned it.  It wasn't very dirty, hardly any carbon, but I  sprayed 
>Gum-Out on it and also sprayed it in the passage on the  throttle body.  I 
>put the IAC valve back in.  I didn't drive it after  doing this.  Later 
>that night, the arctic blast came through (well, for  Houston, TX; lows in 
>the low 30s, highs in the 50s at the most).  Since  the day I cleaned the 
>IAC valve, it has not idled well.  It acts like  it might be too rich, and 
>it won't idle slower than about 700 RPM.
>
>I've done the IAC reset, grounding the diagnostic pin to force the ECM  to 
>extend the IAC plunger fully, and the slowest I can get it to idle  with 
>the IAC valve unplugged is about 600, and it's rough.  It's rough  with the 
>IAC valve connected, both cold and hot, and it idles faster in  Park or 
>Neutral than in Drive.  In Drive it's right about at the target  idle 
>speed, but still rough, but it won't idle down when taken out of  gear.
>
>By "rough" I mean a bad smell from the tailpipes, car shaking, surging,  
>having to really hold my foot on the brake to keep it still at a red  light 
>due to the surging.
>
>So could I have damaged the IAC valve with the Gum-Out?
>
>I broke the scientific method and changed two things at once (OK, so I  
>can't control the weather), and now I don't know if I have an acting-up  
>IAC valve, a fuel leak, or if it just doesn't like the chilled air.
>
>The pintle of the IAC valve looks like it could possibly wear over time  
>and not seal against the throttle body, with or without carbon buildup.
>
>  ---> Jared Ryan <---
>jryan at caminofx.org | http://www.caminofx.org
>
>On Dec 2, 2006, at 9:31 AM, davesnothereman at netscape.net wrote:
>
>>
>>  The TBI trucks w/ 7747 expect intake air temp around 90 deg F or  
>>greater.  The intake air heater is calibrated for this temp.  Most  folks 
>>with older tbi trucks don't seem to know / care.  In an area  where 10 
>>year old trucks are rotted out due to salt, snow, and  humidity it's not 
>>uncommon to see the few left running with no heat  stove left on the 
>>manifold and no tube connected to the snorkel.
>>
>>The question you need to answer is "How good is good enough?"  I have  
>>open element air cleaners on my truck which used to run in temps well  
>>below zero without causing any issues which I can remember.
>>
>>The old carby 2.8 S10's had an electrically heated grid under the carb  to 
>>prevent icing.  A 15-20 mile drive at highway speed at 50 deg temps  could 
>>cause enough restriction to bring vehicle speed below 30 mph if  the 
>>heater was inoperative.
>>
>>Zaphod
>>
>>-----Original Message-----
>>From: jryan at caminofx.org
>>To: gmecm at diy-efi.org
>>Sent: Fri, 1 Dec 2006 1:28 PM
>>Subject: [Gmecm] TBI and EFE
>>
>>
>>Do TBI engines typically need the EFE ThermAC setup to run smoothly in  
>>cold weather?
>>
>>I have an El Camino that has a heat stove on the passenger side, but I  
>>recently changed to a Camaro air cleaner that puts the snorkel on the  
>>driver side (this fits MUCH better with my Camaro serpentine belt  setup). 
>>I will need to put a heat stove on the left-side exhaust  manifold in 
>>order to use the ThermAC.
>>
>>I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't  
>>help. It made a BIG difference in cold-weather running when I had the  
>>QuadraJet carburetor, and TBI is also a wet-manifold system.
>>
>>The reason I ask is that the temperature has dropped into the 30s F,  
>>which is cold for Houston, TX, and the idle is a little rough.  However, 
>>the cold weather moved in on the same day I removed and  cleaned the IAC 
>>valve. It is entirely possible I just need to reset  the minimum-air 
>>setting and the idle will smooth out.
>>
>>Off-idle performance has been perfect, just a little bit of a rough  idle 
>>since it turned cold. I will do the IAC reset this afternoon, but  I still 
>>wonder if making the ThermAC operational will help a lot.
>>
>>I notice that the TBI intake manifolds no longer have the exhaust  
>>crossover under the carburetor/throttle body mounting pad.
>>
>>I hear a lot about ThermAC, like "It only closes in *really* cold  
>>weather. When I had it set up properly with the QuadraJet, it would  close 
>>at least a little bit on sunny warm spring days! It would open  quickly, 
>>but it didn't only work on very cold days, for sure. On very  cold days, 
>>like what we have here, it often wouldn't ever open  completely.
>>_______________________________________________
>>Gmecm mailing list
>>Gmecm at diy-efi.org
>>Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>Main WWW page: http://www.diy-efi.org/gmecm
>>_______________________________________________________________________ _
>>Check Out the new free AIM(R) Mail -- 2 GB of storage and  
>>industry-leading spam and email virus protection.
>>_______________________________________________
>>Gmecm mailing list
>>Gmecm at diy-efi.org
>>Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>Main WWW page: http://www.diy-efi.org/gmecm
>>
>
>_______________________________________________
>Gmecm mailing list
>Gmecm at diy-efi.org
>Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>Main WWW page: http://www.diy-efi.org/gmecm

_________________________________________________________________
Share your latest news with your friends with the Windows Live Spaces 
friends module. 
http://clk.atdmt.com/MSN/go/msnnkwsp0070000001msn/direct/01/?href=http://spaces.live.com/spacesapi.aspx?wx_action=create&wx_url=/friends.aspx&mk



From perfdyn at cwnet.com  Mon Dec  4 01:28:26 2006
From: perfdyn at cwnet.com (Carl Rumberger)
Date: Sun, 3 Dec 2006 23:28:26 -0800
Subject: [Gmecm] TBI and EFE
References: <20061201184949.65883.qmail@web80507.mail.yahoo.com>
Message-ID: <039901c717b7$a4d699d0$0baf5142@D600m>

I have read a number of replies to your cold drivability issues that address throttle body icing. Though icing may indeed be a real concern, especially from a safety standpoint and may contribute to your cold run issues, it is at least equally possible the problem is related to the "747" TBI system not having any Intake Air Temp. (can you say air density) sensing. 

GM choose not to use IAT sensors in Pick-Up applications where the typical owner wasn't likely to be very picky about slight running issues . . . combined with the fact that in these engines the intake and coolant temperatures closely follow each other under most operating conditions (a coolant temp. sensor and single temp. table could substitute for both sensors and tables). 

The truth is these engines can be sensitive to cold intake air / lean A/F ratios. Of course the A/F: vs. Coolant Temp. table can be adjusted richer under cold operation but then you would likely run into slightly rich cold running when the weather turns warm. And yes a TAC system will tend to minimize intake air temp.(air density) variations. I have had the misfortune of tuning a TBI "747" conversion that the customer choose an Edelbrock Performer RPM Air Gap intake manifold combined with a cold air intake system on a Chev. 350 with a mild cam. Trying to get the fueling correct was frustrating not only because of the cold air system but with this intake manifold the changes in IAT no longer even remotely followed the changes to coolant temp.

It is also interesting to note that in those applications where GM thought the owners were more likely to be picky (Caprice / F body) they used a IAT sensor and the 1228746 ECU.


----- Original Message ----- From: Jared Ryan <jryan at caminofx.org>
To: gmecm at diy-efi.org
Sent: Friday, December 1, 2006 12:28:24 PM
Subject: [Gmecm] TBI and EFE


Do TBI engines typically need the EFE ThermAC setup to run smoothly in 
cold weather?

I have an El Camino that has a heat stove on the passenger side, but I 
recently changed to a Camaro air cleaner that puts the snorkel on the 
driver side (this fits MUCH better with my Camaro serpentine belt setup). 
I will need to put a heat stove on the left-side exhaust manifold in order 
to use the ThermAC.

I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help. 
It made a BIG difference in cold-weather running when I had the QuadraJet 
carburetor, and TBI is also a wet-manifold system.

The reason I ask is that the temperature has dropped into the 30s F, which 
is cold for Houston, TX, and the idle is a little rough.  However, the 
cold weather moved in on the same day I removed and cleaned the IAC valve. 
It is entirely possible I just need to reset the minimum-air setting and 
the idle will smooth out.

Off-idle performance has been perfect, just a little bit of a rough idle 
since it turned cold.  I will do the IAC reset this afternoon, but I still 
wonder if making the ThermAC operational will help a lot.

I notice that the TBI intake manifolds no longer have the exhaust 
crossover under the carburetor/throttle body mounting pad.

I hear a lot about ThermAC, like "It only closes in *really* cold weather. 
When I had it set up properly with the QuadraJet, it would close at least 
a little bit on sunny warm spring days!  It would open quickly, but it 
didn't only work on very cold days, for sure.  On very cold days, like 
what we have here, it often wouldn't ever open completely.
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm




From jryan at caminofx.org  Mon Dec  4 14:49:06 2006
From: jryan at caminofx.org (jryan at caminofx.org)
Date: Mon,  4 Dec 2006 14:49:06 -0600
Subject: [Gmecm] TBI and EFE
In-Reply-To: <039901c717b7$a4d699d0$0baf5142@D600m>
References: <20061201184949.65883.qmail@web80507.mail.yahoo.com>
	<039901c717b7$a4d699d0$0baf5142@D600m>
Message-ID: <20061204144906.av9ayvi1b0g04sg4@webmail.caminofx.org>

Well, once again, apparently I fail.

It turns out that the injector cover gasket was leaking.  I took a  
look at it with the air cleaner lid off, and I noticed that the  
left-side throttle plate was wet, but the right-side plate was dry,  
and the part of the gasket on the left side was glistening.  I have a  
dual-plane intake manifold (Edelbrock 3704), so one-half of the  
cylinders were getting a very rich mixture, while one-half were  
getting a lean mixture, apparently.

So I went to the parts store and got a TBI gasket kit, and I replaced  
everything I could without taking the throttle body off the manifold  
(no reason to suspect the base gasket).  I changed the injector  
O-rings, injector cover gasket, IAC valve gasket, etc.

I don't know if this is a best practice but I used petroleum jelly on  
the injector O-rings to try to protect them during installation, as I  
have mashed a lower O-ring in the past by accident, causing a  
super-rich running condition.

At any rate, I started it up and it ran fine, much smoother.  After it  
warmed up, I had to do the whole minimum-air reset procedure, because  
it idled much too fast (due to the mixture being much leaner).

For what it's worth, I actually do have an IAT sensor.  I have a  
strange hodgepodge of components.  The serpentine belt system, 1228746  
ECM and air cleaner are all from a Camaro.  The intake fits under the  
hood of the El Camino nicely and looks like it belongs there.

The other thing the 1228746 has that the '747 seems not to is a  
control for the vapor canister solenoid.  Cars seemed to have a  
solenoid, while pickups did not seem to.  This may also play into your  
thinking - truck owners may not be as sensitive to small variations as  
car owners.

It was 30 degrees F when I started out this morning, and it ran fine -  
no stumble, no rough idling, no black smoke (lotsa white stuff out the  
pipes though!), so apparently it is not critical to preheat the intake  
air.  With the Camaro air cleaner, duct and scoop, it's getting cold  
air from right behind the driver-side headlight, not heated by the  
engine compartment or radiator.

There is one small issue left, and this may be because I'm using the  
ANLU (9C1 350) PROM with a camshaft a little bigger than it was made  
for.  It idles very nicely at all times, very smooth, very close to  
the target speed set in the PROM, but it does something a little funny  
after I have been driving a while and I shift from OD/D to P.  The  
idle jumps up slightly due to the decreased load, then the tachometer  
needle does kind of a pendulum thing, going up and down about 100 RPM  
total.  After about five or six cycles, it stabilizes and stays at the  
set idle speed.  It only does this when shifting from OD/D to P, not  
from P to OD/D.

It acts like it's chasing the target idle speed, but it's such a small  
variation that many people might not notice it happening.  I wonder if  
I should get a scantool and watch the IAC counts, and try fine-tuning  
the throttle plate opening based on the IAC counts.

Thanks to everyone for all the advice.  I am enjoying learning how  
this system is really supposed to work, and starting to really enjoy  
driving the car.

Quoting Carl Rumberger <perfdyn at cwnet.com>:

> I have read a number of replies to your cold drivability issues that  
>  address throttle body icing. Though icing may indeed be a real   
> concern, especially from a safety standpoint and may contribute to   
> your cold run issues, it is at least equally possible the problem is  
>  related to the "747" TBI system not having any Intake Air Temp.  
> (can  you say air density) sensing.
>
> GM choose not to use IAT sensors in Pick-Up applications where the   
> typical owner wasn't likely to be very picky about slight running   
> issues . . . combined with the fact that in these engines the intake  
>  and coolant temperatures closely follow each other under most   
> operating conditions (a coolant temp. sensor and single temp. table   
> could substitute for both sensors and tables).
>
> The truth is these engines can be sensitive to cold intake air /   
> lean A/F ratios. Of course the A/F: vs. Coolant Temp. table can be   
> adjusted richer under cold operation but then you would likely run   
> into slightly rich cold running when the weather turns warm. And yes  
>  a TAC system will tend to minimize intake air temp.(air density)   
> variations. I have had the misfortune of tuning a TBI "747"   
> conversion that the customer choose an Edelbrock Performer RPM Air   
> Gap intake manifold combined with a cold air intake system on a   
> Chev. 350 with a mild cam. Trying to get the fueling correct was   
> frustrating not only because of the cold air system but with this   
> intake manifold the changes in IAT no longer even remotely followed   
> the changes to coolant temp.
>
> It is also interesting to note that in those applications where GM   
> thought the owners were more likely to be picky (Caprice / F body)   
> they used a IAT sensor and the 1228746 ECU.
>
>
> ----- Original Message ----- From: Jared Ryan <jryan at caminofx.org>
> To: gmecm at diy-efi.org
> Sent: Friday, December 1, 2006 12:28:24 PM
> Subject: [Gmecm] TBI and EFE
>
>
> Do TBI engines typically need the EFE ThermAC setup to run smoothly in
> cold weather?
>
> I have an El Camino that has a heat stove on the passenger side, but I
> recently changed to a Camaro air cleaner that puts the snorkel on the
> driver side (this fits MUCH better with my Camaro serpentine belt setup).
> I will need to put a heat stove on the left-side exhaust manifold in order
> to use the ThermAC.
>
> I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help.
> It made a BIG difference in cold-weather running when I had the QuadraJet
> carburetor, and TBI is also a wet-manifold system.
>
> The reason I ask is that the temperature has dropped into the 30s F, which
> is cold for Houston, TX, and the idle is a little rough.  However, the
> cold weather moved in on the same day I removed and cleaned the IAC valve.
> It is entirely possible I just need to reset the minimum-air setting and
> the idle will smooth out.
>
> Off-idle performance has been perfect, just a little bit of a rough idle
> since it turned cold.  I will do the IAC reset this afternoon, but I still
> wonder if making the ThermAC operational will help a lot.
>
> I notice that the TBI intake manifolds no longer have the exhaust
> crossover under the carburetor/throttle body mounting pad.
>
> I hear a lot about ThermAC, like "It only closes in *really* cold weather.
> When I had it set up properly with the QuadraJet, it would close at least
> a little bit on sunny warm spring days!  It would open quickly, but it
> didn't only work on very cold days, for sure.  On very cold days, like
> what we have here, it often wouldn't ever open completely.
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>





From cletrac at comcast.net  Mon Dec  4 17:06:19 2006
From: cletrac at comcast.net (cletrac at comcast.net)
Date: Mon, 04 Dec 2006 23:06:19 +0000
Subject: [Gmecm] P&H Nozzles
Message-ID: <120420062306.15015.4574A9EB00019E2500003AA722070210530C0E9D9B0A040C@comcast.net>

I'm looking for some help in finding an OE application for a 34 PPH peak and hold nozzle for a GM application. The plastic part of the body is gray and there are two numbers stamped on opposite the electrical connection. 1231 is on the left and 5235364 is on the right. The same nozle is sold by MSD under part number 2012.

Thank you

Dave

From captain_krill at yahoo.com  Mon Dec  4 21:29:01 2006
From: captain_krill at yahoo.com (Cowen)
Date: Mon, 4 Dec 2006 19:29:01 -0800 (PST)
Subject: [Gmecm] Stives, and the 2.8l EFE grid
Message-ID: <20061205032901.38303.qmail@web34304.mail.mud.yahoo.com>

Hello folks,
I'm not sure what conditions would cause icing in some
2.8s and not others, but I bought my 2.8 with a carb,
and I heard about how the ceramic comes off the grid
(mine was 20% gone when I looked).  I subsequently
removed the grid entirely, and had no problems driving
on extended ski trips through the Rockies, Idaho, and
up and down the Coast to Whistler and Vancouver's
local mountains.  Over 10 years, altitude, humidity,
and -26 deg temps over the Coquihalla (5,500 feet
highway) to ski in the interior have never caused any
problems.  Maybe the lower engine compartment profile
of the Cherokee (compared to a Blazer) keeps the carb
warmer?

Two winters in, I'm also having no problems with my
unheated Fiero throttle body now on the same engine -
no problems yet, even after a few ski trips to the
interior (3000 ft, -20).

I have experienced icing in an aircraft carb - not
fun!  But not in a car yet...

I doubt stoves make much difference to icing, and I
know the EFE grid was useless (and restrictive!) in my
Jeep!

Just my two cents. :)

**********************END TRANSMISSION**********************


 
____________________________________________________________________________________
Have a burning question?  
Go to www.Answers.yahoo.com and get answers from real people who know.


From Dave.Thomas at us.festo.com  Mon Dec  4 23:00:15 2006
From: Dave.Thomas at us.festo.com (Dave Thomas)
Date: Tue, 5 Dec 2006 00:00:15 -0500
Subject: [Gmecm] 1227747 ACSU promID  Idle Problems
Message-ID: <OF2C37E347.9CA9262E-ON8525723B.0019185A-8525723B.001B78A5@MAIL.DE.FESTO.NET>


I have a 1987 GMC V1500 4WD truck with a 700R4 transmission.  The Prom ID
is ACSU.  I have replaced the original engine with a GM Factory Crate
Replacement for VIN K engines.  All stock except for an Edelbrock EDL-3704
manifold.  I am having some problems with the idling of the engine and
stalling when put into gear.  I have noticed on a cold start that
everything seems to be fine with the exception of BLM of ~154.  As the unit
warms up to temperature, I notice the engine will start to reduce the idle
speed trying for a idle speed of ~625 rpm.  At this point the IAC counts
are hovering around 40 counts.  When I put the truck in gear, the IAC
counts start reducing along with the rpms until the rpm reaches ~525.  At
this point, the IAC counts are usually at 0.  When the vehicle is shifted
back into park or neutral, the idle will raise back up but the IAC counts
will remain at 0.  When the vehicle is put into gear the second time, the
engine will stall and die.  I have tried setting the minimum Idle on the
throttle body to allow the IAC to remain open, however 3-5 counts is the
best I have ever achieved but this did not correct the stalling.  Also, I
have tried the service procedure for checking minimum idle air at 425 rpms
in gear with the IAC unplugged.  I cannot achieve this number without the
vehicle stalling.  I have sprayed TBI cleaner around the intake manifold,
tbi gakset, all vacuum connections and I have not seen the idle raise
showing a vacuum leak.  Also, after stalling the vehicle is very hard to
start and keep running unless you rev the engine up above 1500 rpm and let
of the throttle very slowly.  Also, occasionally the engine will surge up
and down (50-100 rpms) but not too extreme.

We replaced the rotor, cap, wires, spark plugs, knock sensor, O2 sensor,
new EGR valve, PCV valve,  cleaned the throttle body, and all new gaskets
during the engine swap.  The MAP sensor, throttle position sensor, ignition
module, coil, EGR switch,  are from the old engine.  I have also swapped
the IAC motor with one that is known to be good with no change.  The
original engine was gunked up and not allowing the oil to flow back from
the head, after some time of running, oil would enter the exhaust valve
guides on the number 7 and 8 cylinders causing the spark plugs to foul.  I
haven't checked the back pressure from the exhaust system/ cat but it is
suspect.  I also plan to check the Fuel pressure to see if the unit is
functioning within specifications (9-13 psi).  I have ordered an updated
prom with the bin file AMUR which seems to be the latest eprom however I
don't  really expect this will fix the problem.

TPS = 0.66 volts at idle
Map at idle was in spec.

Everything seems to be working fine but obviously something is not.

Any information greatly appreciated,

David Thomas
Food & Packaging SBD Engineer
Festo Corporation
Phone: (704) 527-1427
Fax: (704) 527-7935
email: dave.thomas at us.festo.com



From red83brick at yahoo.com  Mon Dec  4 23:12:23 2006
From: red83brick at yahoo.com (Chris Reynolds)
Date: Mon, 4 Dec 2006 21:12:23 -0800 (PST)
Subject: [Gmecm] 1227747 ACSU promID  Idle Problems
In-Reply-To: <OF2C37E347.9CA9262E-ON8525723B.0019185A-8525723B.001B78A5@MAIL.DE.FESTO.NET>
Message-ID: <279202.77583.qm@web61024.mail.yahoo.com>

Remove the grounds from the engine, clean them, and make sure they are not producing too much resistance.  Also make certain that the ground strap was re-attached when the engine was installed.   EFI systems like well established grounds with low resistance.
   
  Is the new O2 sensor by chance a Bosch?   If so I would get my hands on a KNOWN GOOD AC DELCO unit.   Many of us on the DIY PROM board at Thirdgen.org have found that Bosch O2 sensor do not work well with the O2 sensor constants programmed into the GM ecms and the Proportional Gains that are meant to cause the Air/Fuel Ratio to cycle in closed loop is thrown out of whack.   That could even be severe enough to cause random stalling.   Does the problem occur in Open Loop or Closed Loop?

Dave Thomas <Dave.Thomas at us.festo.com> wrote:
  
I have a 1987 GMC V1500 4WD truck with a 700R4 transmission. The Prom ID
is ACSU. I have replaced the original engine with a GM Factory Crate
Replacement for VIN K engines. All stock except for an Edelbrock EDL-3704
manifold. I am having some problems with the idling of the engine and
stalling when put into gear. I have noticed on a cold start that
everything seems to be fine with the exception of BLM of ~154. As the unit
warms up to temperature, I notice the engine will start to reduce the idle
speed trying for a idle speed of ~625 rpm. At this point the IAC counts
are hovering around 40 counts. When I put the truck in gear, the IAC
counts start reducing along with the rpms until the rpm reaches ~525. At
this point, the IAC counts are usually at 0. When the vehicle is shifted
back into park or neutral, the idle will raise back up but the IAC counts
will remain at 0. When the vehicle is put into gear the second time, the
engine will stall and die. I have tried setting the minimum Idle on the
throttle body to allow the IAC to remain open, however 3-5 counts is the
best I have ever achieved but this did not correct the stalling. Also, I
have tried the service procedure for checking minimum idle air at 425 rpms
in gear with the IAC unplugged. I cannot achieve this number without the
vehicle stalling. I have sprayed TBI cleaner around the intake manifold,
tbi gakset, all vacuum connections and I have not seen the idle raise
showing a vacuum leak. Also, after stalling the vehicle is very hard to
start and keep running unless you rev the engine up above 1500 rpm and let
of the throttle very slowly. Also, occasionally the engine will surge up
and down (50-100 rpms) but not too extreme.

We replaced the rotor, cap, wires, spark plugs, knock sensor, O2 sensor,
new EGR valve, PCV valve, cleaned the throttle body, and all new gaskets
during the engine swap. The MAP sensor, throttle position sensor, ignition
module, coil, EGR switch, are from the old engine. I have also swapped
the IAC motor with one that is known to be good with no change. The
original engine was gunked up and not allowing the oil to flow back from
the head, after some time of running, oil would enter the exhaust valve
guides on the number 7 and 8 cylinders causing the spark plugs to foul. I
haven't checked the back pressure from the exhaust system/ cat but it is
suspect. I also plan to check the Fuel pressure to see if the unit is
functioning within specifications (9-13 psi). I have ordered an updated
prom with the bin file AMUR which seems to be the latest eprom however I
don't really expect this will fix the problem.

TPS = 0.66 volts at idle
Map at idle was in spec.

Everything seems to be working fine but obviously something is not.

Any information greatly appreciated,

David Thomas
Food & Packaging SBD Engineer
Festo Corporation
Phone: (704) 527-1427
Fax: (704) 527-7935
email: dave.thomas at us.festo.com

_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm


 
---------------------------------
Need a quick answer? Get one in minutes from people who know. Ask your question on Yahoo! Answers.

From Dave.Thomas at us.festo.com  Tue Dec  5 07:34:20 2006
From: Dave.Thomas at us.festo.com (Dave Thomas)
Date: Tue, 5 Dec 2006 08:34:20 -0500
Subject: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
Message-ID: <OF4F1647F9.6BCD380D-ON8525723B.004A7D40-8525723B.004A8DE5@MAIL.DE.FESTO.NET>




I have a 1987 GMC V1500 4WD truck with a 700R4 transmission.  The Prom ID
is ACSU.  I have replaced the original engine with a GM Factory Crate
Replacement for VIN K engines.  All stock except for an Edelbrock EDL-3704
manifold.  I am having some problems with the idling of the engine and
stalling when put into gear.  I have noticed on a cold start that
everything seems to be fine with the exception of BLM of ~154.  As the unit
warms up to temperature, I notice the engine will start to reduce the idle
speed trying for a idle speed of ~625 rpm.  At this point the IAC counts
are hovering around 40 counts.  When I put the truck in gear, the IAC
counts start reducing along with the rpms until the rpm reaches ~525.  At
this point, the IAC counts are usually at 0.  When the vehicle is shifted
back into park or neutral, the idle will raise back up but the IAC counts
will remain at 0.  When the vehicle is put into gear the second time, the
engine will stall and die.  I have tried setting the minimum Idle on the
throttle body to allow the IAC to remain open, however 3-5 counts is the
best I have ever achieved but this did not correct the stalling.  Also, I
have tried the service procedure for checking minimum idle air at 425 rpms
in gear with the IAC unplugged.  I cannot achieve this number without the
vehicle stalling.  I have sprayed TBI cleaner around the intake manifold,
tbi gakset, all vacuum connections and I have not seen the idle raise
showing a vacuum leak.  Also, after stalling the vehicle is very hard to
start and keep running unless you rev the engine up above 1500 rpm and let
of the throttle very slowly.  Also, occasionally the engine will surge up
and down (50-100 rpms) but not too extreme.

We replaced the rotor, cap, wires, spark plugs, knock sensor, O2 sensor,
new EGR valve, PCV valve,  cleaned the throttle body, and all new gaskets
during the engine swap.  The MAP sensor, throttle position sensor, ignition
module, coil, EGR switch,  are from the old engine.  I have also swapped
the IAC motor with one that is known to be good with no change.  The
original engine was gunked up and not allowing the oil to flow back from
the head, after some time of running, oil would enter the exhaust valve
guides on the number 7 and 8 cylinders causing the spark plugs to foul.  I
haven't checked the back pressure from the exhaust system/ cat but it is
suspect.  I also plan to check the Fuel pressure to see if the unit is
functioning within specifications (9-13 psi).  I have ordered an updated
prom with the bin file AMUR which seems to be the latest eprom however I
don't  really expect this will fix the problem.

TPS = 0.66 volts at idle
Map at idle was in spec.

Everything seems to be working fine but obviously something is not.

Any information greatly appreciated,

David Thomas
Food & Packaging SBD Engineer
Festo Corporation
Phone: (704) 527-1427
Fax: (704) 527-7935
email: dave.thomas at us.festo.com

_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm





From dunvegan at sbcglobal.net  Tue Dec  5 08:07:52 2006
From: dunvegan at sbcglobal.net (Rick McLeod)
Date: Tue, 5 Dec 2006 06:07:52 -0800 (PST)
Subject: [Gmecm] TBI and EFE
Message-ID: <20061205140752.48286.qmail@web80510.mail.yahoo.com>

J, good news. It was kinda as suspected, something amis from the work being done. Since you have an IAT sensor, it appears to be compensating adaqately, goodness.

I'd suspect a minor tweak on mechanical min idle will cure the hunt, you may have a sensitive setup that it's between counts for correct idle on the IAC and it's trying to settle, which mechanical min idle setting might correct, try just a little bit backed off of min idle to see if that cures it, or maybe add just the slightest bit.

Good luck, stay warm


----- Original Message ----
From: "jryan at caminofx.org" <jryan at caminofx.org>
To: gmecm at diy-efi.org
Sent: Monday, December 4, 2006 2:49:06 PM
Subject: Re: [Gmecm] TBI and EFE


Well, once again, apparently I fail.

It turns out that the injector cover gasket was leaking.  I took a  
look at it with the air cleaner lid off, and I noticed that the  
left-side throttle plate was wet, but the right-side plate was dry,  
and the part of the gasket on the left side was glistening.  I have a  
dual-plane intake manifold (Edelbrock 3704), so one-half of the  
cylinders were getting a very rich mixture, while one-half were  
getting a lean mixture, apparently.

So I went to the parts store and got a TBI gasket kit, and I replaced  
everything I could without taking the throttle body off the manifold  
(no reason to suspect the base gasket).  I changed the injector  
O-rings, injector cover gasket, IAC valve gasket, etc.

I don't know if this is a best practice but I used petroleum jelly on  
the injector O-rings to try to protect them during installation, as I  
have mashed a lower O-ring in the past by accident, causing a  
super-rich running condition.

At any rate, I started it up and it ran fine, much smoother.  After it  
warmed up, I had to do the whole minimum-air reset procedure, because  
it idled much too fast (due to the mixture being much leaner).

For what it's worth, I actually do have an IAT sensor.  I have a  
strange hodgepodge of components.  The serpentine belt system, 1228746  
ECM and air cleaner are all from a Camaro.  The intake fits under the  
hood of the El Camino nicely and looks like it belongs there.

The other thing the 1228746 has that the '747 seems not to is a  
control for the vapor canister solenoid.  Cars seemed to have a  
solenoid, while pickups did not seem to.  This may also play into your  
thinking - truck owners may not be as sensitive to small variations as  
car owners.

It was 30 degrees F when I started out this morning, and it ran fine -  
no stumble, no rough idling, no black smoke (lotsa white stuff out the  
pipes though!), so apparently it is not critical to preheat the intake  
air.  With the Camaro air cleaner, duct and scoop, it's getting cold  
air from right behind the driver-side headlight, not heated by the  
engine compartment or radiator.

There is one small issue left, and this may be because I'm using the  
ANLU (9C1 350) PROM with a camshaft a little bigger than it was made  
for.  It idles very nicely at all times, very smooth, very close to  
the target speed set in the PROM, but it does something a little funny  
after I have been driving a while and I shift from OD/D to P.  The  
idle jumps up slightly due to the decreased load, then the tachometer  
needle does kind of a pendulum thing, going up and down about 100 RPM  
total.  After about five or six cycles, it stabilizes and stays at the  
set idle speed.  It only does this when shifting from OD/D to P, not  
from P to OD/D.

It acts like it's chasing the target idle speed, but it's such a small  
variation that many people might not notice it happening.  I wonder if  
I should get a scantool and watch the IAC counts, and try fine-tuning  
the throttle plate opening based on the IAC counts.

Thanks to everyone for all the advice.  I am enjoying learning how  
this system is really supposed to work, and starting to really enjoy  
driving the car.

Quoting Carl Rumberger <perfdyn at cwnet.com>:

> I have read a number of replies to your cold drivability issues that  
>  address throttle body icing. Though icing may indeed be a real   
> concern, especially from a safety standpoint and may contribute to   
> your cold run issues, it is at least equally possible the problem is  
>  related to the "747" TBI system not having any Intake Air Temp.  
> (can  you say air density) sensing.
>
> GM choose not to use IAT sensors in Pick-Up applications where the   
> typical owner wasn't likely to be very picky about slight running   
> issues . . . combined with the fact that in these engines the intake  
>  and coolant temperatures closely follow each other under most   
> operating conditions (a coolant temp. sensor and single temp. table   
> could substitute for both sensors and tables).
>
> The truth is these engines can be sensitive to cold intake air /   
> lean A/F ratios. Of course the A/F: vs. Coolant Temp. table can be   
> adjusted richer under cold operation but then you would likely run   
> into slightly rich cold running when the weather turns warm. And yes  
>  a TAC system will tend to minimize intake air temp.(air density)   
> variations. I have had the misfortune of tuning a TBI "747"   
> conversion that the customer choose an Edelbrock Performer RPM Air   
> Gap intake manifold combined with a cold air intake system on a   
> Chev. 350 with a mild cam. Trying to get the fueling correct was   
> frustrating not only because of the cold air system but with this   
> intake manifold the changes in IAT no longer even remotely followed   
> the changes to coolant temp.
>
> It is also interesting to note that in those applications where GM   
> thought the owners were more likely to be picky (Caprice / F body)   
> they used a IAT sensor and the 1228746 ECU.
>
>
> ----- Original Message ----- From: Jared Ryan <jryan at caminofx.org>
> To: gmecm at diy-efi.org
> Sent: Friday, December 1, 2006 12:28:24 PM
> Subject: [Gmecm] TBI and EFE
>
>
> Do TBI engines typically need the EFE ThermAC setup to run smoothly in
> cold weather?
>
> I have an El Camino that has a heat stove on the passenger side, but I
> recently changed to a Camaro air cleaner that puts the snorkel on the
> driver side (this fits MUCH better with my Camaro serpentine belt setup).
> I will need to put a heat stove on the left-side exhaust manifold in order
> to use the ThermAC.
>
> I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help.
> It made a BIG difference in cold-weather running when I had the QuadraJet
> carburetor, and TBI is also a wet-manifold system.
>
> The reason I ask is that the temperature has dropped into the 30s F, which
> is cold for Houston, TX, and the idle is a little rough.  However, the
> cold weather moved in on the same day I removed and cleaned the IAC valve.
> It is entirely possible I just need to reset the minimum-air setting and
> the idle will smooth out.
>
> Off-idle performance has been perfect, just a little bit of a rough idle
> since it turned cold.  I will do the IAC reset this afternoon, but I still
> wonder if making the ThermAC operational will help a lot.
>
> I notice that the TBI intake manifolds no longer have the exhaust
> crossover under the carburetor/throttle body mounting pad.
>
> I hear a lot about ThermAC, like "It only closes in *really* cold weather.
> When I had it set up properly with the QuadraJet, it would close at least
> a little bit on sunny warm spring days!  It would open quickly, but it
> didn't only work on very cold days, for sure.  On very cold days, like
> what we have here, it often wouldn't ever open completely.
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>



_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm

From jryan at caminofx.org  Tue Dec  5 08:19:17 2006
From: jryan at caminofx.org (jryan at caminofx.org)
Date: Tue,  5 Dec 2006 08:19:17 -0600
Subject: [Gmecm] TBI and EFE
In-Reply-To: <20061205140752.48286.qmail@web80510.mail.yahoo.com>
References: <20061205140752.48286.qmail@web80510.mail.yahoo.com>
Message-ID: <20061205081917.wr0kh38ozocg0wog@webmail.caminofx.org>

Today was another cold morning (30 F) and it ran well.  (I know cold  
in Houston is not the same as in other parts of the country.   
Fortunately, when it freezes here, there is almost never  
precipitation.  Right now it's 38 with a dewpoint of 29, relative  
humidity 70%, which is more humid than it has been.)

I haven't been letting it idle and warm up at all in the mornings.  I  
just start it and go.  It comes up to operating temperature much  
faster in normal driving than idling, anyway.  Even so, with the iron  
block and heads, I'm on the freeway before it comes up to thermostat  
temperature.

This morning I noticed that when I parked at work and moved the  
gearshift from OD to P, the idle speed stayed high, about 1000 RPM.  I  
moved the lever back to OD, then back to P, and it settled down to the  
speed set in the PROM.  Could this be a misadjusted Park/Neutral  
switch?  I have seen this on occasion on this car, and it seems like  
every time, putting it back in gear and then back in park makes it  
settle down.

I'm actually very surprised at how well the 1989 9C1 PROM works,  
considering I'm using full-size pickup injectors, which to my  
understanding are 61 lb./hr. while the 9C1's might have been 68  
lb./hr.  When there are no fuel leaks at the throttle body (and I hope  
that is cured for good), the drivability is overall excellent.

Quoting Rick McLeod <dunvegan at sbcglobal.net>:

> J, good news. It was kinda as suspected, something amis from the   
> work being done. Since you have an IAT sensor, it appears to be   
> compensating adaqately, goodness.
>
> I'd suspect a minor tweak on mechanical min idle will cure the hunt,  
>  you may have a sensitive setup that it's between counts for correct  
>  idle on the IAC and it's trying to settle, which mechanical min  
> idle  setting might correct, try just a little bit backed off of min  
> idle  to see if that cures it, or maybe add just the slightest bit.
>
> Good luck, stay warm
>
>
> ----- Original Message ----
> From: "jryan at caminofx.org" <jryan at caminofx.org>
> To: gmecm at diy-efi.org
> Sent: Monday, December 4, 2006 2:49:06 PM
> Subject: Re: [Gmecm] TBI and EFE
>
>
> Well, once again, apparently I fail.
>
> It turns out that the injector cover gasket was leaking.  I took a
> look at it with the air cleaner lid off, and I noticed that the
> left-side throttle plate was wet, but the right-side plate was dry,
> and the part of the gasket on the left side was glistening.  I have a
> dual-plane intake manifold (Edelbrock 3704), so one-half of the
> cylinders were getting a very rich mixture, while one-half were
> getting a lean mixture, apparently.
>
> So I went to the parts store and got a TBI gasket kit, and I replaced
> everything I could without taking the throttle body off the manifold
> (no reason to suspect the base gasket).  I changed the injector
> O-rings, injector cover gasket, IAC valve gasket, etc.
>
> I don't know if this is a best practice but I used petroleum jelly on
> the injector O-rings to try to protect them during installation, as I
> have mashed a lower O-ring in the past by accident, causing a
> super-rich running condition.
>
> At any rate, I started it up and it ran fine, much smoother.  After it
> warmed up, I had to do the whole minimum-air reset procedure, because
> it idled much too fast (due to the mixture being much leaner).
>
> For what it's worth, I actually do have an IAT sensor.  I have a
> strange hodgepodge of components.  The serpentine belt system, 1228746
> ECM and air cleaner are all from a Camaro.  The intake fits under the
> hood of the El Camino nicely and looks like it belongs there.
>
> The other thing the 1228746 has that the '747 seems not to is a
> control for the vapor canister solenoid.  Cars seemed to have a
> solenoid, while pickups did not seem to.  This may also play into your
> thinking - truck owners may not be as sensitive to small variations as
> car owners.
>
> It was 30 degrees F when I started out this morning, and it ran fine -
> no stumble, no rough idling, no black smoke (lotsa white stuff out the
> pipes though!), so apparently it is not critical to preheat the intake
> air.  With the Camaro air cleaner, duct and scoop, it's getting cold
> air from right behind the driver-side headlight, not heated by the
> engine compartment or radiator.
>
> There is one small issue left, and this may be because I'm using the
> ANLU (9C1 350) PROM with a camshaft a little bigger than it was made
> for.  It idles very nicely at all times, very smooth, very close to
> the target speed set in the PROM, but it does something a little funny
> after I have been driving a while and I shift from OD/D to P.  The
> idle jumps up slightly due to the decreased load, then the tachometer
> needle does kind of a pendulum thing, going up and down about 100 RPM
> total.  After about five or six cycles, it stabilizes and stays at the
> set idle speed.  It only does this when shifting from OD/D to P, not
> from P to OD/D.
>
> It acts like it's chasing the target idle speed, but it's such a small
> variation that many people might not notice it happening.  I wonder if
> I should get a scantool and watch the IAC counts, and try fine-tuning
> the throttle plate opening based on the IAC counts.
>
> Thanks to everyone for all the advice.  I am enjoying learning how
> this system is really supposed to work, and starting to really enjoy
> driving the car.
>
> Quoting Carl Rumberger <perfdyn at cwnet.com>:
>
>> I have read a number of replies to your cold drivability issues that
>>  address throttle body icing. Though icing may indeed be a real
>> concern, especially from a safety standpoint and may contribute to
>> your cold run issues, it is at least equally possible the problem is
>>  related to the "747" TBI system not having any Intake Air Temp.
>> (can  you say air density) sensing.
>>
>> GM choose not to use IAT sensors in Pick-Up applications where the
>> typical owner wasn't likely to be very picky about slight running
>> issues . . . combined with the fact that in these engines the intake
>>  and coolant temperatures closely follow each other under most
>> operating conditions (a coolant temp. sensor and single temp. table
>> could substitute for both sensors and tables).
>>
>> The truth is these engines can be sensitive to cold intake air /
>> lean A/F ratios. Of course the A/F: vs. Coolant Temp. table can be
>> adjusted richer under cold operation but then you would likely run
>> into slightly rich cold running when the weather turns warm. And yes
>>  a TAC system will tend to minimize intake air temp.(air density)
>> variations. I have had the misfortune of tuning a TBI "747"
>> conversion that the customer choose an Edelbrock Performer RPM Air
>> Gap intake manifold combined with a cold air intake system on a
>> Chev. 350 with a mild cam. Trying to get the fueling correct was
>> frustrating not only because of the cold air system but with this
>> intake manifold the changes in IAT no longer even remotely followed
>> the changes to coolant temp.
>>
>> It is also interesting to note that in those applications where GM
>> thought the owners were more likely to be picky (Caprice / F body)
>> they used a IAT sensor and the 1228746 ECU.
>>
>>
>> ----- Original Message ----- From: Jared Ryan <jryan at caminofx.org>
>> To: gmecm at diy-efi.org
>> Sent: Friday, December 1, 2006 12:28:24 PM
>> Subject: [Gmecm] TBI and EFE
>>
>>
>> Do TBI engines typically need the EFE ThermAC setup to run smoothly in
>> cold weather?
>>
>> I have an El Camino that has a heat stove on the passenger side, but I
>> recently changed to a Camaro air cleaner that puts the snorkel on the
>> driver side (this fits MUCH better with my Camaro serpentine belt setup).
>> I will need to put a heat stove on the left-side exhaust manifold in order
>> to use the ThermAC.
>>
>> I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help.
>> It made a BIG difference in cold-weather running when I had the QuadraJet
>> carburetor, and TBI is also a wet-manifold system.
>>
>> The reason I ask is that the temperature has dropped into the 30s F, which
>> is cold for Houston, TX, and the idle is a little rough.  However, the
>> cold weather moved in on the same day I removed and cleaned the IAC valve.
>> It is entirely possible I just need to reset the minimum-air setting and
>> the idle will smooth out.
>>
>> Off-idle performance has been perfect, just a little bit of a rough idle
>> since it turned cold.  I will do the IAC reset this afternoon, but I still
>> wonder if making the ThermAC operational will help a lot.
>>
>> I notice that the TBI intake manifolds no longer have the exhaust
>> crossover under the carburetor/throttle body mounting pad.
>>
>> I hear a lot about ThermAC, like "It only closes in *really* cold weather.
>> When I had it set up properly with the QuadraJet, it would close at least
>> a little bit on sunny warm spring days!  It would open quickly, but it
>> didn't only work on very cold days, for sure.  On very cold days, like
>> what we have here, it often wouldn't ever open completely.
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>
>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>





From dunvegan at sbcglobal.net  Tue Dec  5 08:46:46 2006
From: dunvegan at sbcglobal.net (Rick McLeod)
Date: Tue, 5 Dec 2006 06:46:46 -0800 (PST)
Subject: [Gmecm] TBI and EFE
Message-ID: <20061205144646.8604.qmail@web80511.mail.yahoo.com>

Could this be a misadjusted Park/Neutral  
switch?

it could be either that or electrical noise/problem masking the ecm from reading that signal, but I'd diagnose by putting a switch in parallel, then when in position where it should be open, (if this is drive, be sure to fimrly plan foot on brake) close the switch and then open and see if it controls idle as expected. You very well may have a 'tired' P/N switch which on the age of vehicle is not out of realm of possiblity.

As for your other question about the jelly on o-rings, from my experience using it is an acceptable practice, usually the 'ooze' will be flushed away on the fuel/wet side and ingested through the engine w/ no mal consequense. The use of Silicone is not accpetable, though, as it can even ins small amounts cause degradation to the O2 sensor and I've herd of problems w/ Cat's but not nearly to the extent of the O2 sensor contamination. So, jelly is OK, silicone (which used to be my preference for seating rubber components in metal like radiator hoses, fuel hoses, and the like) has been replaced with the low-tech old timers solution. Don't use bearing grease though, it is not pure and has additives, where P-jelly is relatively pure. 

:-0 sometimes the obvious is not so!


----- Original Message ----
From: "jryan at caminofx.org" <jryan at caminofx.org>
To: gmecm at diy-efi.org
Sent: Tuesday, December 5, 2006 8:19:17 AM
Subject: Re: [Gmecm] TBI and EFE


Today was another cold morning (30 F) and it ran well.  (I know cold  
in Houston is not the same as in other parts of the country.   
Fortunately, when it freezes here, there is almost never  
precipitation.  Right now it's 38 with a dewpoint of 29, relative  
humidity 70%, which is more humid than it has been.)

I haven't been letting it idle and warm up at all in the mornings.  I  
just start it and go.  It comes up to operating temperature much  
faster in normal driving than idling, anyway.  Even so, with the iron  
block and heads, I'm on the freeway before it comes up to thermostat  
temperature.

This morning I noticed that when I parked at work and moved the  
gearshift from OD to P, the idle speed stayed high, about 1000 RPM.  I  
moved the lever back to OD, then back to P, and it settled down to the  
speed set in the PROM.  Could this be a misadjusted Park/Neutral  
switch?  I have seen this on occasion on this car, and it seems like  
every time, putting it back in gear and then back in park makes it  
settle down.

I'm actually very surprised at how well the 1989 9C1 PROM works,  
considering I'm using full-size pickup injectors, which to my  
understanding are 61 lb./hr. while the 9C1's might have been 68  
lb./hr.  When there are no fuel leaks at the throttle body (and I hope  
that is cured for good), the drivability is overall excellent.

Quoting Rick McLeod <dunvegan at sbcglobal.net>:

> J, good news. It was kinda as suspected, something amis from the   
> work being done. Since you have an IAT sensor, it appears to be   
> compensating adaqately, goodness.
>
> I'd suspect a minor tweak on mechanical min idle will cure the hunt,  
>  you may have a sensitive setup that it's between counts for correct  
>  idle on the IAC and it's trying to settle, which mechanical min  
> idle  setting might correct, try just a little bit backed off of min  
> idle  to see if that cures it, or maybe add just the slightest bit.
>
> Good luck, stay warm
>
>
> ----- Original Message ----
> From: "jryan at caminofx.org" <jryan at caminofx.org>
> To: gmecm at diy-efi.org
> Sent: Monday, December 4, 2006 2:49:06 PM
> Subject: Re: [Gmecm] TBI and EFE
>
>
> Well, once again, apparently I fail.
>
> It turns out that the injector cover gasket was leaking.  I took a
> look at it with the air cleaner lid off, and I noticed that the
> left-side throttle plate was wet, but the right-side plate was dry,
> and the part of the gasket on the left side was glistening.  I have a
> dual-plane intake manifold (Edelbrock 3704), so one-half of the
> cylinders were getting a very rich mixture, while one-half were
> getting a lean mixture, apparently.
>
> So I went to the parts store and got a TBI gasket kit, and I replaced
> everything I could without taking the throttle body off the manifold
> (no reason to suspect the base gasket).  I changed the injector
> O-rings, injector cover gasket, IAC valve gasket, etc.
>
> I don't know if this is a best practice but I used petroleum jelly on
> the injector O-rings to try to protect them during installation, as I
> have mashed a lower O-ring in the past by accident, causing a
> super-rich running condition.
>
> At any rate, I started it up and it ran fine, much smoother.  After it
> warmed up, I had to do the whole minimum-air reset procedure, because
> it idled much too fast (due to the mixture being much leaner).
>
> For what it's worth, I actually do have an IAT sensor.  I have a
> strange hodgepodge of components.  The serpentine belt system, 1228746
> ECM and air cleaner are all from a Camaro.  The intake fits under the
> hood of the El Camino nicely and looks like it belongs there.
>
> The other thing the 1228746 has that the '747 seems not to is a
> control for the vapor canister solenoid.  Cars seemed to have a
> solenoid, while pickups did not seem to.  This may also play into your
> thinking - truck owners may not be as sensitive to small variations as
> car owners.
>
> It was 30 degrees F when I started out this morning, and it ran fine -
> no stumble, no rough idling, no black smoke (lotsa white stuff out the
> pipes though!), so apparently it is not critical to preheat the intake
> air.  With the Camaro air cleaner, duct and scoop, it's getting cold
> air from right behind the driver-side headlight, not heated by the
> engine compartment or radiator.
>
> There is one small issue left, and this may be because I'm using the
> ANLU (9C1 350) PROM with a camshaft a little bigger than it was made
> for.  It idles very nicely at all times, very smooth, very close to
> the target speed set in the PROM, but it does something a little funny
> after I have been driving a while and I shift from OD/D to P.  The
> idle jumps up slightly due to the decreased load, then the tachometer
> needle does kind of a pendulum thing, going up and down about 100 RPM
> total.  After about five or six cycles, it stabilizes and stays at the
> set idle speed.  It only does this when shifting from OD/D to P, not
> from P to OD/D.
>
> It acts like it's chasing the target idle speed, but it's such a small
> variation that many people might not notice it happening.  I wonder if
> I should get a scantool and watch the IAC counts, and try fine-tuning
> the throttle plate opening based on the IAC counts.
>
> Thanks to everyone for all the advice.  I am enjoying learning how
> this system is really supposed to work, and starting to really enjoy
> driving the car.
>
> Quoting Carl Rumberger <perfdyn at cwnet.com>:
>
>> I have read a number of replies to your cold drivability issues that
>>  address throttle body icing. Though icing may indeed be a real
>> concern, especially from a safety standpoint and may contribute to
>> your cold run issues, it is at least equally possible the problem is
>>  related to the "747" TBI system not having any Intake Air Temp.
>> (can  you say air density) sensing.
>>
>> GM choose not to use IAT sensors in Pick-Up applications where the
>> typical owner wasn't likely to be very picky about slight running
>> issues . . . combined with the fact that in these engines the intake
>>  and coolant temperatures closely follow each other under most
>> operating conditions (a coolant temp. sensor and single temp. table
>> could substitute for both sensors and tables).
>>
>> The truth is these engines can be sensitive to cold intake air /
>> lean A/F ratios. Of course the A/F: vs. Coolant Temp. table can be
>> adjusted richer under cold operation but then you would likely run
>> into slightly rich cold running when the weather turns warm. And yes
>>  a TAC system will tend to minimize intake air temp.(air density)
>> variations. I have had the misfortune of tuning a TBI "747"
>> conversion that the customer choose an Edelbrock Performer RPM Air
>> Gap intake manifold combined with a cold air intake system on a
>> Chev. 350 with a mild cam. Trying to get the fueling correct was
>> frustrating not only because of the cold air system but with this
>> intake manifold the changes in IAT no longer even remotely followed
>> the changes to coolant temp.
>>
>> It is also interesting to note that in those applications where GM
>> thought the owners were more likely to be picky (Caprice / F body)
>> they used a IAT sensor and the 1228746 ECU.
>>
>>
>> ----- Original Message ----- From: Jared Ryan <jryan at caminofx.org>
>> To: gmecm at diy-efi.org
>> Sent: Friday, December 1, 2006 12:28:24 PM
>> Subject: [Gmecm] TBI and EFE
>>
>>
>> Do TBI engines typically need the EFE ThermAC setup to run smoothly in
>> cold weather?
>>
>> I have an El Camino that has a heat stove on the passenger side, but I
>> recently changed to a Camaro air cleaner that puts the snorkel on the
>> driver side (this fits MUCH better with my Camaro serpentine belt setup).
>> I will need to put a heat stove on the left-side exhaust manifold in order
>> to use the ThermAC.
>>
>> I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help.
>> It made a BIG difference in cold-weather running when I had the QuadraJet
>> carburetor, and TBI is also a wet-manifold system.
>>
>> The reason I ask is that the temperature has dropped into the 30s F, which
>> is cold for Houston, TX, and the idle is a little rough.  However, the
>> cold weather moved in on the same day I removed and cleaned the IAC valve.
>> It is entirely possible I just need to reset the minimum-air setting and
>> the idle will smooth out.
>>
>> Off-idle performance has been perfect, just a little bit of a rough idle
>> since it turned cold.  I will do the IAC reset this afternoon, but I still
>> wonder if making the ThermAC operational will help a lot.
>>
>> I notice that the TBI intake manifolds no longer have the exhaust
>> crossover under the carburetor/throttle body mounting pad.
>>
>> I hear a lot about ThermAC, like "It only closes in *really* cold weather.
>> When I had it set up properly with the QuadraJet, it would close at least
>> a little bit on sunny warm spring days!  It would open quickly, but it
>> didn't only work on very cold days, for sure.  On very cold days, like
>> what we have here, it often wouldn't ever open completely.
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>
>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>



_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm

From davida1 at hiwaay.net  Tue Dec  5 08:46:12 2006
From: davida1 at hiwaay.net (David Allen)
Date: Tue, 5 Dec 2006 08:46:12 -0600
Subject: [Gmecm] TBI and EFE
References: <20061205140752.48286.qmail@web80510.mail.yahoo.com>
	<20061205081917.wr0kh38ozocg0wog@webmail.caminofx.org>
Message-ID: <017901c7187c$20a82410$0600a8c0@yancey.com>

  It could be the IAC Steps Vs Coolant Temp table in the ECM calibration.
  When tuning my Nova, I could never get it to idle correctly until I lowered the values in the table locations near normal operating range. Symptoms were similar to yours. I have all the table entries in the normal operating temp range set to "63."
  The engine was only slightly modified but it was enough to affect the idle.
David

----- Original Message ----- 
From: <jryan at caminofx.org>
To: <gmecm at diy-efi.org>
Sent: Tuesday, December 05, 2006 8:19 AM
Subject: Re: [Gmecm] TBI and EFE


> Today was another cold morning (30 F) and it ran well.  (I know cold  
> in Houston is not the same as in other parts of the country.   
> Fortunately, when it freezes here, there is almost never  
> precipitation.  Right now it's 38 with a dewpoint of 29, relative  
> humidity 70%, which is more humid than it has been.)
> 
> I haven't been letting it idle and warm up at all in the mornings.  I  
> just start it and go.  It comes up to operating temperature much  
> faster in normal driving than idling, anyway.  Even so, with the iron  
> block and heads, I'm on the freeway before it comes up to thermostat  
> temperature.
> 
> This morning I noticed that when I parked at work and moved the  
> gearshift from OD to P, the idle speed stayed high, about 1000 RPM.  I  
> moved the lever back to OD, then back to P, and it settled down to the  
> speed set in the PROM.  Could this be a misadjusted Park/Neutral  
> switch?  I have seen this on occasion on this car, and it seems like  
> every time, putting it back in gear and then back in park makes it  
> settle down.
> 
> I'm actually very surprised at how well the 1989 9C1 PROM works,  
> considering I'm using full-size pickup injectors, which to my  
> understanding are 61 lb./hr. while the 9C1's might have been 68  
> lb./hr.  When there are no fuel leaks at the throttle body (and I hope  
> that is cured for good), the drivability is overall excellent.
> 
> Quoting Rick McLeod <dunvegan at sbcglobal.net>:
> 
>> J, good news. It was kinda as suspected, something amis from the   
>> work being done. Since you have an IAT sensor, it appears to be   
>> compensating adaqately, goodness.
>>
>> I'd suspect a minor tweak on mechanical min idle will cure the hunt,  
>>  you may have a sensitive setup that it's between counts for correct  
>>  idle on the IAC and it's trying to settle, which mechanical min  
>> idle  setting might correct, try just a little bit backed off of min  
>> idle  to see if that cures it, or maybe add just the slightest bit.
>>
>> Good luck, stay warm
>>
>>
>> ----- Original Message ----
>> From: "jryan at caminofx.org" <jryan at caminofx.org>
>> To: gmecm at diy-efi.org
>> Sent: Monday, December 4, 2006 2:49:06 PM
>> Subject: Re: [Gmecm] TBI and EFE
>>
>>
>> Well, once again, apparently I fail.
>>
>> It turns out that the injector cover gasket was leaking.  I took a
>> look at it with the air cleaner lid off, and I noticed that the
>> left-side throttle plate was wet, but the right-side plate was dry,
>> and the part of the gasket on the left side was glistening.  I have a
>> dual-plane intake manifold (Edelbrock 3704), so one-half of the
>> cylinders were getting a very rich mixture, while one-half were
>> getting a lean mixture, apparently.
>>
>> So I went to the parts store and got a TBI gasket kit, and I replaced
>> everything I could without taking the throttle body off the manifold
>> (no reason to suspect the base gasket).  I changed the injector
>> O-rings, injector cover gasket, IAC valve gasket, etc.
>>
>> I don't know if this is a best practice but I used petroleum jelly on
>> the injector O-rings to try to protect them during installation, as I
>> have mashed a lower O-ring in the past by accident, causing a
>> super-rich running condition.
>>
>> At any rate, I started it up and it ran fine, much smoother.  After it
>> warmed up, I had to do the whole minimum-air reset procedure, because
>> it idled much too fast (due to the mixture being much leaner).
>>
>> For what it's worth, I actually do have an IAT sensor.  I have a
>> strange hodgepodge of components.  The serpentine belt system, 1228746
>> ECM and air cleaner are all from a Camaro.  The intake fits under the
>> hood of the El Camino nicely and looks like it belongs there.
>>
>> The other thing the 1228746 has that the '747 seems not to is a
>> control for the vapor canister solenoid.  Cars seemed to have a
>> solenoid, while pickups did not seem to.  This may also play into your
>> thinking - truck owners may not be as sensitive to small variations as
>> car owners.
>>
>> It was 30 degrees F when I started out this morning, and it ran fine -
>> no stumble, no rough idling, no black smoke (lotsa white stuff out the
>> pipes though!), so apparently it is not critical to preheat the intake
>> air.  With the Camaro air cleaner, duct and scoop, it's getting cold
>> air from right behind the driver-side headlight, not heated by the
>> engine compartment or radiator.
>>
>> There is one small issue left, and this may be because I'm using the
>> ANLU (9C1 350) PROM with a camshaft a little bigger than it was made
>> for.  It idles very nicely at all times, very smooth, very close to
>> the target speed set in the PROM, but it does something a little funny
>> after I have been driving a while and I shift from OD/D to P.  The
>> idle jumps up slightly due to the decreased load, then the tachometer
>> needle does kind of a pendulum thing, going up and down about 100 RPM
>> total.  After about five or six cycles, it stabilizes and stays at the
>> set idle speed.  It only does this when shifting from OD/D to P, not
>> from P to OD/D.
>>
>> It acts like it's chasing the target idle speed, but it's such a small
>> variation that many people might not notice it happening.  I wonder if
>> I should get a scantool and watch the IAC counts, and try fine-tuning
>> the throttle plate opening based on the IAC counts.
>>
>> Thanks to everyone for all the advice.  I am enjoying learning how
>> this system is really supposed to work, and starting to really enjoy
>> driving the car.
>>
>> Quoting Carl Rumberger <perfdyn at cwnet.com>:
>>
>>> I have read a number of replies to your cold drivability issues that
>>>  address throttle body icing. Though icing may indeed be a real
>>> concern, especially from a safety standpoint and may contribute to
>>> your cold run issues, it is at least equally possible the problem is
>>>  related to the "747" TBI system not having any Intake Air Temp.
>>> (can  you say air density) sensing.
>>>
>>> GM choose not to use IAT sensors in Pick-Up applications where the
>>> typical owner wasn't likely to be very picky about slight running
>>> issues . . . combined with the fact that in these engines the intake
>>>  and coolant temperatures closely follow each other under most
>>> operating conditions (a coolant temp. sensor and single temp. table
>>> could substitute for both sensors and tables).
>>>
>>> The truth is these engines can be sensitive to cold intake air /
>>> lean A/F ratios. Of course the A/F: vs. Coolant Temp. table can be
>>> adjusted richer under cold operation but then you would likely run
>>> into slightly rich cold running when the weather turns warm. And yes
>>>  a TAC system will tend to minimize intake air temp.(air density)
>>> variations. I have had the misfortune of tuning a TBI "747"
>>> conversion that the customer choose an Edelbrock Performer RPM Air
>>> Gap intake manifold combined with a cold air intake system on a
>>> Chev. 350 with a mild cam. Trying to get the fueling correct was
>>> frustrating not only because of the cold air system but with this
>>> intake manifold the changes in IAT no longer even remotely followed
>>> the changes to coolant temp.
>>>
>>> It is also interesting to note that in those applications where GM
>>> thought the owners were more likely to be picky (Caprice / F body)
>>> they used a IAT sensor and the 1228746 ECU.
>>>
>>>
>>> ----- Original Message ----- From: Jared Ryan <jryan at caminofx.org>
>>> To: gmecm at diy-efi.org
>>> Sent: Friday, December 1, 2006 12:28:24 PM
>>> Subject: [Gmecm] TBI and EFE
>>>
>>>
>>> Do TBI engines typically need the EFE ThermAC setup to run smoothly in
>>> cold weather?
>>>
>>> I have an El Camino that has a heat stove on the passenger side, but I
>>> recently changed to a Camaro air cleaner that puts the snorkel on the
>>> driver side (this fits MUCH better with my Camaro serpentine belt setup).
>>> I will need to put a heat stove on the left-side exhaust manifold in order
>>> to use the ThermAC.
>>>
>>> I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help.
>>> It made a BIG difference in cold-weather running when I had the QuadraJet
>>> carburetor, and TBI is also a wet-manifold system.
>>>
>>> The reason I ask is that the temperature has dropped into the 30s F, which
>>> is cold for Houston, TX, and the idle is a little rough.  However, the
>>> cold weather moved in on the same day I removed and cleaned the IAC valve.
>>> It is entirely possible I just need to reset the minimum-air setting and
>>> the idle will smooth out.
>>>
>>> Off-idle performance has been perfect, just a little bit of a rough idle
>>> since it turned cold.  I will do the IAC reset this afternoon, but I still
>>> wonder if making the ThermAC operational will help a lot.
>>>
>>> I notice that the TBI intake manifolds no longer have the exhaust
>>> crossover under the carburetor/throttle body mounting pad.
>>>
>>> I hear a lot about ThermAC, like "It only closes in *really* cold weather.
>>> When I had it set up properly with the QuadraJet, it would close at least
>>> a little bit on sunny warm spring days!  It would open quickly, but it
>>> didn't only work on very cold days, for sure.  On very cold days, like
>>> what we have here, it often wouldn't ever open completely.
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>
>>>
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>
>>
>>
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
> 
> 
> 
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 
>


From jryan at caminofx.org  Tue Dec  5 12:30:18 2006
From: jryan at caminofx.org (jryan at caminofx.org)
Date: Tue,  5 Dec 2006 12:30:18 -0600
Subject: [Gmecm] TBI and EFE
In-Reply-To: <20061205144646.8604.qmail@web80511.mail.yahoo.com>
References: <20061205144646.8604.qmail@web80511.mail.yahoo.com>
Message-ID: <20061205123018.0tg4wnsl4wkcoc8g@webmail.caminofx.org>

Actually, now that I think about it, I think the P/N switch has been  
replaced since I've owned the car (since 1997).  IIRC, the P/N switch  
is part of the backup light switch, and it is adjustable.  My backup  
lights are working, but in the past I have had to occasionally get  
under the dashboard and slide the adjustable part of the P/N switch  
over.  It can tend to gradually creep over time.

I'll try adjusting the switch and see if that cures the occasional  
fast idle in Park.  It never happens in gear, and it never "hunts" in  
gear at all.

Quoting Rick McLeod <dunvegan at sbcglobal.net>:

> Could this be a misadjusted Park/Neutral
> switch?
>
> it could be either that or electrical noise/problem masking the ecm   
> from reading that signal, but I'd diagnose by putting a switch in   
> parallel, then when in position where it should be open, (if this is  
>  drive, be sure to fimrly plan foot on brake) close the switch and   
> then open and see if it controls idle as expected. You very well may  
>  have a 'tired' P/N switch which on the age of vehicle is not out of  
>  realm of possiblity.
>
> As for your other question about the jelly on o-rings, from my   
> experience using it is an acceptable practice, usually the 'ooze'   
> will be flushed away on the fuel/wet side and ingested through the   
> engine w/ no mal consequense. The use of Silicone is not accpetable,  
>  though, as it can even ins small amounts cause degradation to the  
> O2  sensor and I've herd of problems w/ Cat's but not nearly to the   
> extent of the O2 sensor contamination. So, jelly is OK, silicone   
> (which used to be my preference for seating rubber components in   
> metal like radiator hoses, fuel hoses, and the like) has been   
> replaced with the low-tech old timers solution. Don't use bearing   
> grease though, it is not pure and has additives, where P-jelly is   
> relatively pure.
>
> :-0 sometimes the obvious is not so!
>
>
> ----- Original Message ----
> From: "jryan at caminofx.org" <jryan at caminofx.org>
> To: gmecm at diy-efi.org
> Sent: Tuesday, December 5, 2006 8:19:17 AM
> Subject: Re: [Gmecm] TBI and EFE
>
>
> Today was another cold morning (30 F) and it ran well.  (I know cold
> in Houston is not the same as in other parts of the country.
> Fortunately, when it freezes here, there is almost never
> precipitation.  Right now it's 38 with a dewpoint of 29, relative
> humidity 70%, which is more humid than it has been.)
>
> I haven't been letting it idle and warm up at all in the mornings.  I
> just start it and go.  It comes up to operating temperature much
> faster in normal driving than idling, anyway.  Even so, with the iron
> block and heads, I'm on the freeway before it comes up to thermostat
> temperature.
>
> This morning I noticed that when I parked at work and moved the
> gearshift from OD to P, the idle speed stayed high, about 1000 RPM.  I
> moved the lever back to OD, then back to P, and it settled down to the
> speed set in the PROM.  Could this be a misadjusted Park/Neutral
> switch?  I have seen this on occasion on this car, and it seems like
> every time, putting it back in gear and then back in park makes it
> settle down.
>
> I'm actually very surprised at how well the 1989 9C1 PROM works,
> considering I'm using full-size pickup injectors, which to my
> understanding are 61 lb./hr. while the 9C1's might have been 68
> lb./hr.  When there are no fuel leaks at the throttle body (and I hope
> that is cured for good), the drivability is overall excellent.
>
> Quoting Rick McLeod <dunvegan at sbcglobal.net>:
>
>> J, good news. It was kinda as suspected, something amis from the
>> work being done. Since you have an IAT sensor, it appears to be
>> compensating adaqately, goodness.
>>
>> I'd suspect a minor tweak on mechanical min idle will cure the hunt,
>>  you may have a sensitive setup that it's between counts for correct
>>  idle on the IAC and it's trying to settle, which mechanical min
>> idle  setting might correct, try just a little bit backed off of min
>> idle  to see if that cures it, or maybe add just the slightest bit.
>>
>> Good luck, stay warm
>>
>>
>> ----- Original Message ----
>> From: "jryan at caminofx.org" <jryan at caminofx.org>
>> To: gmecm at diy-efi.org
>> Sent: Monday, December 4, 2006 2:49:06 PM
>> Subject: Re: [Gmecm] TBI and EFE
>>
>>
>> Well, once again, apparently I fail.
>>
>> It turns out that the injector cover gasket was leaking.  I took a
>> look at it with the air cleaner lid off, and I noticed that the
>> left-side throttle plate was wet, but the right-side plate was dry,
>> and the part of the gasket on the left side was glistening.  I have a
>> dual-plane intake manifold (Edelbrock 3704), so one-half of the
>> cylinders were getting a very rich mixture, while one-half were
>> getting a lean mixture, apparently.
>>
>> So I went to the parts store and got a TBI gasket kit, and I replaced
>> everything I could without taking the throttle body off the manifold
>> (no reason to suspect the base gasket).  I changed the injector
>> O-rings, injector cover gasket, IAC valve gasket, etc.
>>
>> I don't know if this is a best practice but I used petroleum jelly on
>> the injector O-rings to try to protect them during installation, as I
>> have mashed a lower O-ring in the past by accident, causing a
>> super-rich running condition.
>>
>> At any rate, I started it up and it ran fine, much smoother.  After it
>> warmed up, I had to do the whole minimum-air reset procedure, because
>> it idled much too fast (due to the mixture being much leaner).
>>
>> For what it's worth, I actually do have an IAT sensor.  I have a
>> strange hodgepodge of components.  The serpentine belt system, 1228746
>> ECM and air cleaner are all from a Camaro.  The intake fits under the
>> hood of the El Camino nicely and looks like it belongs there.
>>
>> The other thing the 1228746 has that the '747 seems not to is a
>> control for the vapor canister solenoid.  Cars seemed to have a
>> solenoid, while pickups did not seem to.  This may also play into your
>> thinking - truck owners may not be as sensitive to small variations as
>> car owners.
>>
>> It was 30 degrees F when I started out this morning, and it ran fine -
>> no stumble, no rough idling, no black smoke (lotsa white stuff out the
>> pipes though!), so apparently it is not critical to preheat the intake
>> air.  With the Camaro air cleaner, duct and scoop, it's getting cold
>> air from right behind the driver-side headlight, not heated by the
>> engine compartment or radiator.
>>
>> There is one small issue left, and this may be because I'm using the
>> ANLU (9C1 350) PROM with a camshaft a little bigger than it was made
>> for.  It idles very nicely at all times, very smooth, very close to
>> the target speed set in the PROM, but it does something a little funny
>> after I have been driving a while and I shift from OD/D to P.  The
>> idle jumps up slightly due to the decreased load, then the tachometer
>> needle does kind of a pendulum thing, going up and down about 100 RPM
>> total.  After about five or six cycles, it stabilizes and stays at the
>> set idle speed.  It only does this when shifting from OD/D to P, not
>> from P to OD/D.
>>
>> It acts like it's chasing the target idle speed, but it's such a small
>> variation that many people might not notice it happening.  I wonder if
>> I should get a scantool and watch the IAC counts, and try fine-tuning
>> the throttle plate opening based on the IAC counts.
>>
>> Thanks to everyone for all the advice.  I am enjoying learning how
>> this system is really supposed to work, and starting to really enjoy
>> driving the car.
>>
>> Quoting Carl Rumberger <perfdyn at cwnet.com>:
>>
>>> I have read a number of replies to your cold drivability issues that
>>>  address throttle body icing. Though icing may indeed be a real
>>> concern, especially from a safety standpoint and may contribute to
>>> your cold run issues, it is at least equally possible the problem is
>>>  related to the "747" TBI system not having any Intake Air Temp.
>>> (can  you say air density) sensing.
>>>
>>> GM choose not to use IAT sensors in Pick-Up applications where the
>>> typical owner wasn't likely to be very picky about slight running
>>> issues . . . combined with the fact that in these engines the intake
>>>  and coolant temperatures closely follow each other under most
>>> operating conditions (a coolant temp. sensor and single temp. table
>>> could substitute for both sensors and tables).
>>>
>>> The truth is these engines can be sensitive to cold intake air /
>>> lean A/F ratios. Of course the A/F: vs. Coolant Temp. table can be
>>> adjusted richer under cold operation but then you would likely run
>>> into slightly rich cold running when the weather turns warm. And yes
>>>  a TAC system will tend to minimize intake air temp.(air density)
>>> variations. I have had the misfortune of tuning a TBI "747"
>>> conversion that the customer choose an Edelbrock Performer RPM Air
>>> Gap intake manifold combined with a cold air intake system on a
>>> Chev. 350 with a mild cam. Trying to get the fueling correct was
>>> frustrating not only because of the cold air system but with this
>>> intake manifold the changes in IAT no longer even remotely followed
>>> the changes to coolant temp.
>>>
>>> It is also interesting to note that in those applications where GM
>>> thought the owners were more likely to be picky (Caprice / F body)
>>> they used a IAT sensor and the 1228746 ECU.
>>>
>>>
>>> ----- Original Message ----- From: Jared Ryan <jryan at caminofx.org>
>>> To: gmecm at diy-efi.org
>>> Sent: Friday, December 1, 2006 12:28:24 PM
>>> Subject: [Gmecm] TBI and EFE
>>>
>>>
>>> Do TBI engines typically need the EFE ThermAC setup to run smoothly in
>>> cold weather?
>>>
>>> I have an El Camino that has a heat stove on the passenger side, but I
>>> recently changed to a Camaro air cleaner that puts the snorkel on the
>>> driver side (this fits MUCH better with my Camaro serpentine belt setup).
>>> I will need to put a heat stove on the left-side exhaust manifold in order
>>> to use the ThermAC.
>>>
>>> I assume it wouldn't be there (on '88-'92 TBI F-bodies) if it didn't help.
>>> It made a BIG difference in cold-weather running when I had the QuadraJet
>>> carburetor, and TBI is also a wet-manifold system.
>>>
>>> The reason I ask is that the temperature has dropped into the 30s F, which
>>> is cold for Houston, TX, and the idle is a little rough.  However, the
>>> cold weather moved in on the same day I removed and cleaned the IAC valve.
>>> It is entirely possible I just need to reset the minimum-air setting and
>>> the idle will smooth out.
>>>
>>> Off-idle performance has been perfect, just a little bit of a rough idle
>>> since it turned cold.  I will do the IAC reset this afternoon, but I still
>>> wonder if making the ThermAC operational will help a lot.
>>>
>>> I notice that the TBI intake manifolds no longer have the exhaust
>>> crossover under the carburetor/throttle body mounting pad.
>>>
>>> I hear a lot about ThermAC, like "It only closes in *really* cold weather.
>>> When I had it set up properly with the QuadraJet, it would close at least
>>> a little bit on sunny warm spring days!  It would open quickly, but it
>>> didn't only work on very cold days, for sure.  On very cold days, like
>>> what we have here, it often wouldn't ever open completely.
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>
>>>
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>
>>
>>
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>
>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>





From william.lucke at highspeedlink.net  Wed Dec  6 14:47:41 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Wed, 06 Dec 2006 15:47:41 -0500
Subject: [Gmecm] GM circuit numbers
Message-ID: <45772C6D.3000109@highspeedlink.net>

My dad recently did a project (building full instrumentation cluster for 
'90 Suburban) that would have been MUCH easier if he'd had an index of 
GM circuit numbers. He's found where to get that info for $30, but was 
hoping that there was a free resource somewhere that had it. Anybody 
know of such?


Will


From Steve.Ravet at arm.com  Wed Dec  6 17:41:40 2006
From: Steve.Ravet at arm.com (Steve Ravet)
Date: Wed, 6 Dec 2006 17:41:40 -0600
Subject: [Gmecm] GM circuit numbers
Message-ID: <DBB2E4C4173F1749B6C743414061178301795A40@NASDAQ.usa.Arm.com>

That would be useful information.

The service manual for my '86 S-10 Blazer had that chart in it, but the
service manual for the '91 Caprice (which donated it's 5.7L TBI motor to
said Blazer) did not have that chart.  I have not found that chart in
the '98 full size pickup service manual that I have, although at 8
billion pages, I might have missed it.  Can you give us a pointer to
where you found that information?

--steve 

> -----Original Message-----
> From: gmecm-bounces at diy-efi.org 
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of William Lucke
> Sent: Wednesday, December 06, 2006 2:48 PM
> To: gmecm at diy-efi.org
> Subject: [Gmecm] GM circuit numbers
> 
> My dad recently did a project (building full instrumentation 
> cluster for '90 Suburban) that would have been MUCH easier if 
> he'd had an index of GM circuit numbers. He's found where to 
> get that info for $30, but was hoping that there was a free 
> resource somewhere that had it. Anybody know of such?
> 
> 
> Will
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 


From lwester at lincsat.com  Thu Dec  7 09:26:45 2006
From: lwester at lincsat.com (Programmer)
Date: Thu, 7 Dec 2006 08:26:45 -0700
Subject: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
References: <OF4F1647F9.6BCD380D-ON8525723B.004A7D40-8525723B.004A8DE5@MAIL.DE.FESTO.NET>
Message-ID: <001001c71a14$20237050$0200a8c0@WESTER2>

PCV valve correct ?
EGR leaking ? (IS this the correct EGR valve from GM ?)
The updated PROM ACSU to AKAJ to AMUR had several related TSB's ...and these 
updates fixed those concerns.
TSB 88-180-6E AKAJ
TSB 88-T-109
TSB 88-T-25
TSB 88-87-657-109
TSB 88-88-657-108AMUR

Lyndon.

----- Original Message ----- 
From: "Dave Thomas" <Dave.Thomas at us.festo.com>
To: <gmecm at diy-efi.org>
Sent: Tuesday, December 05, 2006 6:34 AM
Subject: [Gmecm] SER# 1227747 ACSU promID Idle Problems


>
>
>
> I have a 1987 GMC V1500 4WD truck with a 700R4 transmission.  The Prom ID
> is ACSU.  I have replaced the original engine with a GM Factory Crate
> Replacement for VIN K engines.  All stock except for an Edelbrock EDL-3704
> manifold.  I am having some problems with the idling of the engine and
> stalling when put into gear.  I have noticed on a cold start that
> everything seems to be fine with the exception of BLM of ~154.  As the 
> unit
> warms up to temperature, I notice the engine will start to reduce the idle
> speed trying for a idle speed of ~625 rpm.  At this point the IAC counts
> are hovering around 40 counts.  When I put the truck in gear, the IAC
> counts start reducing along with the rpms until the rpm reaches ~525.  At
> this point, the IAC counts are usually at 0.  When the vehicle is shifted
> back into park or neutral, the idle will raise back up but the IAC counts
> will remain at 0.  When the vehicle is put into gear the second time, the
> engine will stall and die.  I have tried setting the minimum Idle on the
> throttle body to allow the IAC to remain open, however 3-5 counts is the
> best I have ever achieved but this did not correct the stalling.  Also, I
> have tried the service procedure for checking minimum idle air at 425 rpms
> in gear with the IAC unplugged.  I cannot achieve this number without the
> vehicle stalling.  I have sprayed TBI cleaner around the intake manifold,
> tbi gakset, all vacuum connections and I have not seen the idle raise
> showing a vacuum leak.  Also, after stalling the vehicle is very hard to
> start and keep running unless you rev the engine up above 1500 rpm and let
> of the throttle very slowly.  Also, occasionally the engine will surge up
> and down (50-100 rpms) but not too extreme.
>
> We replaced the rotor, cap, wires, spark plugs, knock sensor, O2 sensor,
> new EGR valve, PCV valve,  cleaned the throttle body, and all new gaskets
> during the engine swap.  The MAP sensor, throttle position sensor, 
> ignition
> module, coil, EGR switch,  are from the old engine.  I have also swapped
> the IAC motor with one that is known to be good with no change.  The
> original engine was gunked up and not allowing the oil to flow back from
> the head, after some time of running, oil would enter the exhaust valve
> guides on the number 7 and 8 cylinders causing the spark plugs to foul.  I
> haven't checked the back pressure from the exhaust system/ cat but it is
> suspect.  I also plan to check the Fuel pressure to see if the unit is
> functioning within specifications (9-13 psi).  I have ordered an updated
> prom with the bin file AMUR which seems to be the latest eprom however I
> don't  really expect this will fix the problem.
>
> TPS = 0.66 volts at idle
> Map at idle was in spec.
>
> Everything seems to be working fine but obviously something is not.
>
> Any information greatly appreciated,
>
> David Thomas
> Food & Packaging SBD Engineer
> Festo Corporation
> Phone: (704) 527-1427
> Fax: (704) 527-7935
> email: dave.thomas at us.festo.com
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>
>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm 



From Dave.Thomas at us.festo.com  Thu Dec  7 09:41:26 2006
From: Dave.Thomas at us.festo.com (Dave Thomas)
Date: Thu, 7 Dec 2006 10:41:26 -0500
Subject: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
In-Reply-To: <001001c71a14$20237050$0200a8c0@WESTER2>
Message-ID: <OF3BAF3ABE.3C13B4B2-ON8525723D.0055BF50-8525723D.005630AE@MAIL.DE.FESTO.NET>

PCV Valve - Brand new from GM
EGR Valve - Brand new from GM ( I also tried removing the vacuum hose and
plugging the  vac hose to eliminate the switch leaking)
I plan on checking the fuel pressure, exhaust backpressure and install new
AMUR prom.  I am going to try to reset the min. air at idle, and I have
diacom that I will try to record some data.  I also plan on rechecking the
MAP sensor and test the vacuum with a pressure gauge to see if there are
any inconsistencies.

I have not replaced the fuel pressure regulator, but I would expect the
fuel pressure test should show any problems with it.

Thanks for your suggestions,

David Thomas
Food & Packaging SBD Engineer
Festo Corporation
Phone: (704) 527-1427
Fax: (704) 527-7935
email: dave.thomas at us.festo.com






                                                                                                                
         "Programmer" <lwester at lincsat.com>                         12/07/2006 10:30 AM                         
                                                                                                                



      Sent by:

      gmecm-bounces at diy-efi.org 12/07/2006 10:26 AM

      Please respond to
gmecm at diy-efi.org

|--+------------------------>
|  |                        |
|--+------------------------>
  >-----------------------------------------------------------------------------------------------------------------------------------------|
  |                                                                                                                                         |
  |                                                                                                                                         |
  |                                                                                                                                       To|
  |        <gmecm at diy-efi.org>                                                                                                              |
  |                                                                                                                                       cc|
  |                                                                                                                                         |
  |                                                                                                                                  Subject|
  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems                                                                              |
  |                                                                                                                                         |
  |                                                                                                                                         |
  |                                                                                                                                         |
  |                                                                                                                                         |
  |                                                                                                                                         |
  >-----------------------------------------------------------------------------------------------------------------------------------------|




PCV valve correct ?
EGR leaking ? (IS this the correct EGR valve from GM ?)
The updated PROM ACSU to AKAJ to AMUR had several related TSB's ...and
these
updates fixed those concerns.
TSB 88-180-6E AKAJ
TSB 88-T-109
TSB 88-T-25
TSB 88-87-657-109
TSB 88-88-657-108AMUR

Lyndon.

----- Original Message -----
From: "Dave Thomas" <Dave.Thomas at us.festo.com>
To: <gmecm at diy-efi.org>
Sent: Tuesday, December 05, 2006 6:34 AM
Subject: [Gmecm] SER# 1227747 ACSU promID Idle Problems


>
>
>
> I have a 1987 GMC V1500 4WD truck with a 700R4 transmission.  The Prom ID
> is ACSU.  I have replaced the original engine with a GM Factory Crate
> Replacement for VIN K engines.  All stock except for an Edelbrock
EDL-3704
> manifold.  I am having some problems with the idling of the engine and
> stalling when put into gear.  I have noticed on a cold start that
> everything seems to be fine with the exception of BLM of ~154.  As the
> unit
> warms up to temperature, I notice the engine will start to reduce the
idle
> speed trying for a idle speed of ~625 rpm.  At this point the IAC counts
> are hovering around 40 counts.  When I put the truck in gear, the IAC
> counts start reducing along with the rpms until the rpm reaches ~525.  At
> this point, the IAC counts are usually at 0.  When the vehicle is shifted
> back into park or neutral, the idle will raise back up but the IAC counts
> will remain at 0.  When the vehicle is put into gear the second time, the
> engine will stall and die.  I have tried setting the minimum Idle on the
> throttle body to allow the IAC to remain open, however 3-5 counts is the
> best I have ever achieved but this did not correct the stalling.  Also, I
> have tried the service procedure for checking minimum idle air at 425
rpms
> in gear with the IAC unplugged.  I cannot achieve this number without the
> vehicle stalling.  I have sprayed TBI cleaner around the intake manifold,
> tbi gakset, all vacuum connections and I have not seen the idle raise
> showing a vacuum leak.  Also, after stalling the vehicle is very hard to
> start and keep running unless you rev the engine up above 1500 rpm and
let
> of the throttle very slowly.  Also, occasionally the engine will surge up
> and down (50-100 rpms) but not too extreme.
>
> We replaced the rotor, cap, wires, spark plugs, knock sensor, O2 sensor,
> new EGR valve, PCV valve,  cleaned the throttle body, and all new gaskets
> during the engine swap.  The MAP sensor, throttle position sensor,
> ignition
> module, coil, EGR switch,  are from the old engine.  I have also swapped
> the IAC motor with one that is known to be good with no change.  The
> original engine was gunked up and not allowing the oil to flow back from
> the head, after some time of running, oil would enter the exhaust valve
> guides on the number 7 and 8 cylinders causing the spark plugs to foul.
I
> haven't checked the back pressure from the exhaust system/ cat but it is
> suspect.  I also plan to check the Fuel pressure to see if the unit is
> functioning within specifications (9-13 psi).  I have ordered an updated
> prom with the bin file AMUR which seems to be the latest eprom however I
> don't  really expect this will fix the problem.
>
> TPS = 0.66 volts at idle
> Map at idle was in spec.
>
> Everything seems to be working fine but obviously something is not.
>
> Any information greatly appreciated,
>
> David Thomas
> Food & Packaging SBD Engineer
> Festo Corporation
> Phone: (704) 527-1427
> Fax: (704) 527-7935
> email: dave.thomas at us.festo.com
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>
>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm

_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm






From lwester at lincsat.com  Thu Dec  7 18:38:12 2006
From: lwester at lincsat.com (Programmer)
Date: Thu, 7 Dec 2006 17:38:12 -0700
Subject: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
References: <OF3BAF3ABE.3C13B4B2-ON8525723D.0055BF50-8525723D.005630AE@MAIL.DE.FESTO.NET>
Message-ID: <001901c71a61$2a4a22c0$0200a8c0@WESTER2>

Diagnose from the latest calibration first...but your "0" IAC count is 
definitely indicating unmetered or uncontrolled air.

Lyndon.

----- Original Message ----- 
From: "Dave Thomas" <Dave.Thomas at us.festo.com>
To: <gmecm at diy-efi.org>
Sent: Thursday, December 07, 2006 8:41 AM
Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems


> PCV Valve - Brand new from GM
> EGR Valve - Brand new from GM ( I also tried removing the vacuum hose and
> plugging the  vac hose to eliminate the switch leaking)
> I plan on checking the fuel pressure, exhaust backpressure and install new
> AMUR prom.  I am going to try to reset the min. air at idle, and I have
> diacom that I will try to record some data.  I also plan on rechecking the
> MAP sensor and test the vacuum with a pressure gauge to see if there are
> any inconsistencies.
>
> I have not replaced the fuel pressure regulator, but I would expect the
> fuel pressure test should show any problems with it.
>
> Thanks for your suggestions,
>
> David Thomas
> Food & Packaging SBD Engineer
> Festo Corporation
> Phone: (704) 527-1427
> Fax: (704) 527-7935
> email: dave.thomas at us.festo.com
>
>
>
>
>
>
>
>         "Programmer" <lwester at lincsat.com> 
> 12/07/2006 10:30 AM
>
>
>
>
>      Sent by:
>
>      gmecm-bounces at diy-efi.org 12/07/2006 10:26 AM
>
>      Please respond to
> gmecm at diy-efi.org
>
> |--+------------------------>
> |  |                        |
> |--+------------------------>
> 
>  >-----------------------------------------------------------------------------------------------------------------------------------------|
>  | 
> |
>  | 
> |
>  | 
> To|
>  |        <gmecm at diy-efi.org> 
> |
>  | 
> cc|
>  | 
> |
>  | 
> Subject|
>  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems 
> |
>  | 
> |
>  | 
> |
>  | 
> |
>  | 
> |
>  | 
> |
> 
>  >-----------------------------------------------------------------------------------------------------------------------------------------|
>
>
>
>
> PCV valve correct ?
> EGR leaking ? (IS this the correct EGR valve from GM ?)
> The updated PROM ACSU to AKAJ to AMUR had several related TSB's ...and
> these
> updates fixed those concerns.
> TSB 88-180-6E AKAJ
> TSB 88-T-109
> TSB 88-T-25
> TSB 88-87-657-109
> TSB 88-88-657-108AMUR
>
> Lyndon.
>
> ----- Original Message -----
> From: "Dave Thomas" <Dave.Thomas at us.festo.com>
> To: <gmecm at diy-efi.org>
> Sent: Tuesday, December 05, 2006 6:34 AM
> Subject: [Gmecm] SER# 1227747 ACSU promID Idle Problems
>
>
>>
>>
>>
>> I have a 1987 GMC V1500 4WD truck with a 700R4 transmission.  The Prom ID
>> is ACSU.  I have replaced the original engine with a GM Factory Crate
>> Replacement for VIN K engines.  All stock except for an Edelbrock
> EDL-3704
>> manifold.  I am having some problems with the idling of the engine and
>> stalling when put into gear.  I have noticed on a cold start that
>> everything seems to be fine with the exception of BLM of ~154.  As the
>> unit
>> warms up to temperature, I notice the engine will start to reduce the
> idle
>> speed trying for a idle speed of ~625 rpm.  At this point the IAC counts
>> are hovering around 40 counts.  When I put the truck in gear, the IAC
>> counts start reducing along with the rpms until the rpm reaches ~525.  At
>> this point, the IAC counts are usually at 0.  When the vehicle is shifted
>> back into park or neutral, the idle will raise back up but the IAC counts
>> will remain at 0.  When the vehicle is put into gear the second time, the
>> engine will stall and die.  I have tried setting the minimum Idle on the
>> throttle body to allow the IAC to remain open, however 3-5 counts is the
>> best I have ever achieved but this did not correct the stalling.  Also, I
>> have tried the service procedure for checking minimum idle air at 425
> rpms
>> in gear with the IAC unplugged.  I cannot achieve this number without the
>> vehicle stalling.  I have sprayed TBI cleaner around the intake manifold,
>> tbi gakset, all vacuum connections and I have not seen the idle raise
>> showing a vacuum leak.  Also, after stalling the vehicle is very hard to
>> start and keep running unless you rev the engine up above 1500 rpm and
> let
>> of the throttle very slowly.  Also, occasionally the engine will surge up
>> and down (50-100 rpms) but not too extreme.
>>
>> We replaced the rotor, cap, wires, spark plugs, knock sensor, O2 sensor,
>> new EGR valve, PCV valve,  cleaned the throttle body, and all new gaskets
>> during the engine swap.  The MAP sensor, throttle position sensor,
>> ignition
>> module, coil, EGR switch,  are from the old engine.  I have also swapped
>> the IAC motor with one that is known to be good with no change.  The
>> original engine was gunked up and not allowing the oil to flow back from
>> the head, after some time of running, oil would enter the exhaust valve
>> guides on the number 7 and 8 cylinders causing the spark plugs to foul.
> I
>> haven't checked the back pressure from the exhaust system/ cat but it is
>> suspect.  I also plan to check the Fuel pressure to see if the unit is
>> functioning within specifications (9-13 psi).  I have ordered an updated
>> prom with the bin file AMUR which seems to be the latest eprom however I
>> don't  really expect this will fix the problem.
>>
>> TPS = 0.66 volts at idle
>> Map at idle was in spec.
>>
>> Everything seems to be working fine but obviously something is not.
>>
>> Any information greatly appreciated,
>>
>> David Thomas
>> Food & Packaging SBD Engineer
>> Festo Corporation
>> Phone: (704) 527-1427
>> Fax: (704) 527-7935
>> email: dave.thomas at us.festo.com
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>>
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>
>
>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm 



From Dave.Thomas at us.festo.com  Thu Dec  7 23:00:56 2006
From: Dave.Thomas at us.festo.com (Dave Thomas)
Date: Fri, 8 Dec 2006 00:00:56 -0500
Subject: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
In-Reply-To: <001901c71a61$2a4a22c0$0200a8c0@WESTER2>
Message-ID: <OF7616DBE2.FC4D5A02-ON8525723E.001A2A4E-8525723E.001B8C70@MAIL.DE.FESTO.NET>

Here is what I have observed today.  Replace ACSU prom with AMUR prom.  Ran
pretty good until closed loop mode.  Same problem with stalling when
putting into gear the second time. (I.E. put vehicle in gear, watch Idle
air counts go to zero, return to park or neutral, vehicle rpms raise, but
IAC stays at 0, try to put vehicle back into gear and the vehicle cuts off.

I cannot for the life of me get the car to run to set the minimum air idle
setting which I believe to be 425 rpm +/- 25 rpm, with vehicle in gear.
This is after I ground the diagnostic pins on the ALDL connector, wait 10
seconds for the IAC motor to zero out, remove ground from ALDL and start
engine.  As I turn the idle screw down where the rpm's are around 500 rpm,
the vehicle just stalls out.  Recrank engine, truck runs fine until you
place into gear, the IAC counts start counting down, if it stops before
reaching 0, the car stalls out everytime with the new prom calibration,
which has idle at operating temp set to 500 rpm.  The old prom ran at 525
rpm.  I checked the vacuum, at one point the engine was surging up and down
and the vacuum gauge was sweeping back and forth between 15" HG and 17"
HG..  I have a trouble shooting guide which says to look at the ignition if
vacuum varies between 1 and 2 " HG.  Can the coil or ignition module be
heating up and just dropping out at low idle speeds?

I plugged the EGR,AIR vacuum port, the vapor canistor vacuum port and
plugged my vacuum gauge into the port on the rear fitting of the manifold.
This left the PCV valve port, Map port, and vacuum booster connected to the
system.  I then squirted TBI cleaner and WD40 around the base of the
Throttle body, all vacuum lines  and capped ports, fitting where vacuum
booster is connected to the manifold and no leak has shown.

Also checked the fuel pressure at the outlet of the fuel filter.  It was
dead nuts on 13 psi.

I'm not sure why I can't get the min. idle air to 400 rpms?  Any
suggestions?

Once again, Thanks for reading and any suggestions,

David Thomas
Food & Packaging SBD Engineer
Festo Corporation
Phone: (704) 527-1427
Fax: (704) 527-7935
email: dave.thomas at us.festo.com






                                                                                                                
         "Programmer" <lwester at lincsat.com>                         12/07/2006 07:39 PM                         
                                                                                                                



      Sent by:

      gmecm-bounces at diy-efi.org 12/07/2006 07:38 PM

      Please respond to
gmecm at diy-efi.org

|--+-------------------------------->
|  |                                |
|--+-------------------------------->
  >--------------------------------------------------------------------------------------------------------------------------------------------------|
  |                                                                                                                                                  |
  |                                                                                                                                                  |
  |                                                                                                                                                To|
  |        <gmecm at diy-efi.org>                                                                                                                       |
  |                                                                                                                                                cc|
  |                                                                                                                                                  |
  |                                                                                                                                           Subject|
  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems                                                                                       |
  |                                                                                                                                                  |
  |                                                                                                                                                  |
  |                                                                                                                                                  |
  |                                                                                                                                                  |
  |                                                                                                                                                  |
  >--------------------------------------------------------------------------------------------------------------------------------------------------|




Diagnose from the latest calibration first...but your "0" IAC count is
definitely indicating unmetered or uncontrolled air.

Lyndon.

----- Original Message -----
From: "Dave Thomas" <Dave.Thomas at us.festo.com>
To: <gmecm at diy-efi.org>
Sent: Thursday, December 07, 2006 8:41 AM
Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems


> PCV Valve - Brand new from GM
> EGR Valve - Brand new from GM ( I also tried removing the vacuum hose and
> plugging the  vac hose to eliminate the switch leaking)
> I plan on checking the fuel pressure, exhaust backpressure and install
new
> AMUR prom.  I am going to try to reset the min. air at idle, and I have
> diacom that I will try to record some data.  I also plan on rechecking
the
> MAP sensor and test the vacuum with a pressure gauge to see if there are
> any inconsistencies.
>
> I have not replaced the fuel pressure regulator, but I would expect the
> fuel pressure test should show any problems with it.
>
> Thanks for your suggestions,
>
> David Thomas
> Food & Packaging SBD Engineer
> Festo Corporation
> Phone: (704) 527-1427
> Fax: (704) 527-7935
> email: dave.thomas at us.festo.com
>
>
>
>
>
>
>
>         "Programmer" <lwester at lincsat.com>
> 12/07/2006 10:30 AM
>
>
>
>
>      Sent by:
>
>      gmecm-bounces at diy-efi.org 12/07/2006 10:26 AM
>
>      Please respond to
> gmecm at diy-efi.org
>
> |--+------------------------>
> |  |                        |
> |--+------------------------>
>
>
>-----------------------------------------------------------------------------------------------------------------------------------------|

>  |
> |
>  |
> |
>  |
> To|
>  |        <gmecm at diy-efi.org>
> |
>  |
> cc|
>  |
> |
>  |
> Subject|
>  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
> |
>  |
> |
>  |
> |
>  |
> |
>  |
> |
>  |
> |
>
>
>-----------------------------------------------------------------------------------------------------------------------------------------|

>
>
>
>
> PCV valve correct ?
> EGR leaking ? (IS this the correct EGR valve from GM ?)
> The updated PROM ACSU to AKAJ to AMUR had several related TSB's ...and
> these
> updates fixed those concerns.
> TSB 88-180-6E AKAJ
> TSB 88-T-109
> TSB 88-T-25
> TSB 88-87-657-109
> TSB 88-88-657-108AMUR
>
> Lyndon.
>
> ----- Original Message -----
> From: "Dave Thomas" <Dave.Thomas at us.festo.com>
> To: <gmecm at diy-efi.org>
> Sent: Tuesday, December 05, 2006 6:34 AM
> Subject: [Gmecm] SER# 1227747 ACSU promID Idle Problems
>
>
>>
>>
>>
>> I have a 1987 GMC V1500 4WD truck with a 700R4 transmission.  The Prom
ID
>> is ACSU.  I have replaced the original engine with a GM Factory Crate
>> Replacement for VIN K engines.  All stock except for an Edelbrock
> EDL-3704
>> manifold.  I am having some problems with the idling of the engine and
>> stalling when put into gear.  I have noticed on a cold start that
>> everything seems to be fine with the exception of BLM of ~154.  As the
>> unit
>> warms up to temperature, I notice the engine will start to reduce the
> idle
>> speed trying for a idle speed of ~625 rpm.  At this point the IAC counts
>> are hovering around 40 counts.  When I put the truck in gear, the IAC
>> counts start reducing along with the rpms until the rpm reaches ~525.
At
>> this point, the IAC counts are usually at 0.  When the vehicle is
shifted
>> back into park or neutral, the idle will raise back up but the IAC
counts
>> will remain at 0.  When the vehicle is put into gear the second time,
the
>> engine will stall and die.  I have tried setting the minimum Idle on the
>> throttle body to allow the IAC to remain open, however 3-5 counts is the
>> best I have ever achieved but this did not correct the stalling.  Also,
I
>> have tried the service procedure for checking minimum idle air at 425
> rpms
>> in gear with the IAC unplugged.  I cannot achieve this number without
the
>> vehicle stalling.  I have sprayed TBI cleaner around the intake
manifold,
>> tbi gakset, all vacuum connections and I have not seen the idle raise
>> showing a vacuum leak.  Also, after stalling the vehicle is very hard to
>> start and keep running unless you rev the engine up above 1500 rpm and
> let
>> of the throttle very slowly.  Also, occasionally the engine will surge
up
>> and down (50-100 rpms) but not too extreme.
>>
>> We replaced the rotor, cap, wires, spark plugs, knock sensor, O2 sensor,
>> new EGR valve, PCV valve,  cleaned the throttle body, and all new
gaskets
>> during the engine swap.  The MAP sensor, throttle position sensor,
>> ignition
>> module, coil, EGR switch,  are from the old engine.  I have also swapped
>> the IAC motor with one that is known to be good with no change.  The
>> original engine was gunked up and not allowing the oil to flow back from
>> the head, after some time of running, oil would enter the exhaust valve
>> guides on the number 7 and 8 cylinders causing the spark plugs to foul.
> I
>> haven't checked the back pressure from the exhaust system/ cat but it is
>> suspect.  I also plan to check the Fuel pressure to see if the unit is
>> functioning within specifications (9-13 psi).  I have ordered an updated
>> prom with the bin file AMUR which seems to be the latest eprom however I
>> don't  really expect this will fix the problem.
>>
>> TPS = 0.66 volts at idle
>> Map at idle was in spec.
>>
>> Everything seems to be working fine but obviously something is not.
>>
>> Any information greatly appreciated,
>>
>> David Thomas
>> Food & Packaging SBD Engineer
>> Festo Corporation
>> Phone: (704) 527-1427
>> Fax: (704) 527-7935
>> email: dave.thomas at us.festo.com
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>>
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>
>
>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm

_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm






From davida1 at hiwaay.net  Fri Dec  8 07:58:14 2006
From: davida1 at hiwaay.net (David Allen)
Date: Fri, 8 Dec 2006 07:58:14 -0600
Subject: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
References: <OF7616DBE2.FC4D5A02-ON8525723E.001A2A4E-8525723E.001B8C70@MAIL.DE.FESTO.NET>
Message-ID: <002601c71ad0$eb921e50$0700a8c0@yancey.com>

  This may have already been addressed but... If the EGR valve pintle (the piece that closes and opens the exhaust flow) is stuck, even a little, it will cause similar idle stalling.
  Sometimes the act of changing the EGR valve will dislodge some carbon from inside the manifold passage.  Then a crumb will immediately hold-open the new EGR valve. Essentially this is causing a huge internal vacuum leak betweent he manifold and exhaust.
  Pull the valve and look for any junk in the pintle.  
  I guess you have checked for bad intake gaskets?  Pull the PCV valve out of the valvecover and plug the valvecover hole.  Locate the other valvecover hole (where the vent hose goes to the air filter) and place your thumb over it.  If you feel vacuum (in spite of the PCV valve not being connected) then your intake gaskets may be blown/ torn on the bottom edge, drawing air from inside the block where the carb-cleaner test will not catch it.
  Also a slow response from the MAP sensor due to a plugged or collapsed vacuum hose is devastating to a TBI system. The ECM will not compensate immediately for changes in air pressure and the engine will run lean or rich under transient conditions.
  If this was running before the engine was repaced, then likely something "happened" during the engine remove / install.
  Hope this helps!
David

----- Original Message ----- 
From: "Dave Thomas" <Dave.Thomas at us.festo.com>
To: <gmecm at diy-efi.org>
Sent: Thursday, December 07, 2006 11:00 PM
Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems


> Here is what I have observed today.  Replace ACSU prom with AMUR prom.  Ran
> pretty good until closed loop mode.  Same problem with stalling when
> putting into gear the second time. (I.E. put vehicle in gear, watch Idle
> air counts go to zero, return to park or neutral, vehicle rpms raise, but
> IAC stays at 0, try to put vehicle back into gear and the vehicle cuts off.
> 
> I cannot for the life of me get the car to run to set the minimum air idle
> setting which I believe to be 425 rpm +/- 25 rpm, with vehicle in gear.
> This is after I ground the diagnostic pins on the ALDL connector, wait 10
> seconds for the IAC motor to zero out, remove ground from ALDL and start
> engine.  As I turn the idle screw down where the rpm's are around 500 rpm,
> the vehicle just stalls out.  Recrank engine, truck runs fine until you
> place into gear, the IAC counts start counting down, if it stops before
> reaching 0, the car stalls out everytime with the new prom calibration,
> which has idle at operating temp set to 500 rpm.  The old prom ran at 525
> rpm.  I checked the vacuum, at one point the engine was surging up and down
> and the vacuum gauge was sweeping back and forth between 15" HG and 17"
> HG..  I have a trouble shooting guide which says to look at the ignition if
> vacuum varies between 1 and 2 " HG.  Can the coil or ignition module be
> heating up and just dropping out at low idle speeds?
> 
> I plugged the EGR,AIR vacuum port, the vapor canistor vacuum port and
> plugged my vacuum gauge into the port on the rear fitting of the manifold.
> This left the PCV valve port, Map port, and vacuum booster connected to the
> system.  I then squirted TBI cleaner and WD40 around the base of the
> Throttle body, all vacuum lines  and capped ports, fitting where vacuum
> booster is connected to the manifold and no leak has shown.
> 
> Also checked the fuel pressure at the outlet of the fuel filter.  It was
> dead nuts on 13 psi.
> 
> I'm not sure why I can't get the min. idle air to 400 rpms?  Any
> suggestions?
> 
> Once again, Thanks for reading and any suggestions,
> 
> David Thomas
> Food & Packaging SBD Engineer
> Festo Corporation
> Phone: (704) 527-1427
> Fax: (704) 527-7935
> email: dave.thomas at us.festo.com
> 
> 
> 
> 
> 
> 
>                                                                                                                
>         "Programmer" <lwester at lincsat.com>                         12/07/2006 07:39 PM                         
>                                                                                                                
> 
> 
> 
>      Sent by:
> 
>      gmecm-bounces at diy-efi.org 12/07/2006 07:38 PM
> 
>      Please respond to
> gmecm at diy-efi.org
> 
> |--+-------------------------------->
> |  |                                |
> |--+-------------------------------->
>  >--------------------------------------------------------------------------------------------------------------------------------------------------|
>  |                                                                                                                                                  |
>  |                                                                                                                                                  |
>  |                                                                                                                                                To|
>  |        <gmecm at diy-efi.org>                                                                                                                       |
>  |                                                                                                                                                cc|
>  |                                                                                                                                                  |
>  |                                                                                                                                           Subject|
>  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems                                                                                       |
>  |                                                                                                                                                  |
>  |                                                                                                                                                  |
>  |                                                                                                                                                  |
>  |                                                                                                                                                  |
>  |                                                                                                                                                  |
>  >--------------------------------------------------------------------------------------------------------------------------------------------------|
> 
> 
> 
> 
> Diagnose from the latest calibration first...but your "0" IAC count is
> definitely indicating unmetered or uncontrolled air.
> 
> Lyndon.
> 
> ----- Original Message -----
> From: "Dave Thomas" <Dave.Thomas at us.festo.com>
> To: <gmecm at diy-efi.org>
> Sent: Thursday, December 07, 2006 8:41 AM
> Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems
> 
> 
>> PCV Valve - Brand new from GM
>> EGR Valve - Brand new from GM ( I also tried removing the vacuum hose and
>> plugging the  vac hose to eliminate the switch leaking)
>> I plan on checking the fuel pressure, exhaust backpressure and install
> new
>> AMUR prom.  I am going to try to reset the min. air at idle, and I have
>> diacom that I will try to record some data.  I also plan on rechecking
> the
>> MAP sensor and test the vacuum with a pressure gauge to see if there are
>> any inconsistencies.
>>
>> I have not replaced the fuel pressure regulator, but I would expect the
>> fuel pressure test should show any problems with it.
>>
>> Thanks for your suggestions,
>>
>> David Thomas
>> Food & Packaging SBD Engineer
>> Festo Corporation
>> Phone: (704) 527-1427
>> Fax: (704) 527-7935
>> email: dave.thomas at us.festo.com
>>
>>
>>
>>
>>
>>
>>
>>         "Programmer" <lwester at lincsat.com>
>> 12/07/2006 10:30 AM
>>
>>
>>
>>
>>      Sent by:
>>
>>      gmecm-bounces at diy-efi.org 12/07/2006 10:26 AM
>>
>>      Please respond to
>> gmecm at diy-efi.org
>>
>> |--+------------------------>
>> |  |                        |
>> |--+------------------------>
>>
>>
>>-----------------------------------------------------------------------------------------------------------------------------------------|
> 
>>  |
>> |
>>  |
>> |
>>  |
>> To|
>>  |        <gmecm at diy-efi.org>
>> |
>>  |
>> cc|
>>  |
>> |
>>  |
>> Subject|
>>  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
>> |
>>  |
>> |
>>  |
>> |
>>  |
>> |
>>  |
>> |
>>  |
>> |
>>
>>
>>-----------------------------------------------------------------------------------------------------------------------------------------|
> 
>>
>>
>>
>>
>> PCV valve correct ?
>> EGR leaking ? (IS this the correct EGR valve from GM ?)
>> The updated PROM ACSU to AKAJ to AMUR had several related TSB's ...and
>> these
>> updates fixed those concerns.
>> TSB 88-180-6E AKAJ
>> TSB 88-T-109
>> TSB 88-T-25
>> TSB 88-87-657-109
>> TSB 88-88-657-108AMUR
>>
>> Lyndon.
>>
>> ----- Original Message -----
>> From: "Dave Thomas" <Dave.Thomas at us.festo.com>
>> To: <gmecm at diy-efi.org>
>> Sent: Tuesday, December 05, 2006 6:34 AM
>> Subject: [Gmecm] SER# 1227747 ACSU promID Idle Problems
>>
>>
>>>
>>>
>>>
>>> I have a 1987 GMC V1500 4WD truck with a 700R4 transmission.  The Prom
> ID
>>> is ACSU.  I have replaced the original engine with a GM Factory Crate
>>> Replacement for VIN K engines.  All stock except for an Edelbrock
>> EDL-3704
>>> manifold.  I am having some problems with the idling of the engine and
>>> stalling when put into gear.  I have noticed on a cold start that
>>> everything seems to be fine with the exception of BLM of ~154.  As the
>>> unit
>>> warms up to temperature, I notice the engine will start to reduce the
>> idle
>>> speed trying for a idle speed of ~625 rpm.  At this point the IAC counts
>>> are hovering around 40 counts.  When I put the truck in gear, the IAC
>>> counts start reducing along with the rpms until the rpm reaches ~525.
> At
>>> this point, the IAC counts are usually at 0.  When the vehicle is
> shifted
>>> back into park or neutral, the idle will raise back up but the IAC
> counts
>>> will remain at 0.  When the vehicle is put into gear the second time,
> the
>>> engine will stall and die.  I have tried setting the minimum Idle on the
>>> throttle body to allow the IAC to remain open, however 3-5 counts is the
>>> best I have ever achieved but this did not correct the stalling.  Also,
> I
>>> have tried the service procedure for checking minimum idle air at 425
>> rpms
>>> in gear with the IAC unplugged.  I cannot achieve this number without
> the
>>> vehicle stalling.  I have sprayed TBI cleaner around the intake
> manifold,
>>> tbi gakset, all vacuum connections and I have not seen the idle raise
>>> showing a vacuum leak.  Also, after stalling the vehicle is very hard to
>>> start and keep running unless you rev the engine up above 1500 rpm and
>> let
>>> of the throttle very slowly.  Also, occasionally the engine will surge
> up
>>> and down (50-100 rpms) but not too extreme.
>>>
>>> We replaced the rotor, cap, wires, spark plugs, knock sensor, O2 sensor,
>>> new EGR valve, PCV valve,  cleaned the throttle body, and all new
> gaskets
>>> during the engine swap.  The MAP sensor, throttle position sensor,
>>> ignition
>>> module, coil, EGR switch,  are from the old engine.  I have also swapped
>>> the IAC motor with one that is known to be good with no change.  The
>>> original engine was gunked up and not allowing the oil to flow back from
>>> the head, after some time of running, oil would enter the exhaust valve
>>> guides on the number 7 and 8 cylinders causing the spark plugs to foul.
>> I
>>> haven't checked the back pressure from the exhaust system/ cat but it is
>>> suspect.  I also plan to check the Fuel pressure to see if the unit is
>>> functioning within specifications (9-13 psi).  I have ordered an updated
>>> prom with the bin file AMUR which seems to be the latest eprom however I
>>> don't  really expect this will fix the problem.
>>>
>>> TPS = 0.66 volts at idle
>>> Map at idle was in spec.
>>>
>>> Everything seems to be working fine but obviously something is not.
>>>
>>> Any information greatly appreciated,
>>>
>>> David Thomas
>>> Food & Packaging SBD Engineer
>>> Festo Corporation
>>> Phone: (704) 527-1427
>>> Fax: (704) 527-7935
>>> email: dave.thomas at us.festo.com
>>>
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>
>>>
>>>
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>>
>>
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
> 
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 
> 
> 
> 
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>


From Dave.Thomas at us.festo.com  Fri Dec  8 08:25:20 2006
From: Dave.Thomas at us.festo.com (Dave Thomas)
Date: Fri, 8 Dec 2006 09:25:20 -0500
Subject: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
In-Reply-To: <002601c71ad0$eb921e50$0700a8c0@yancey.com>
Message-ID: <OFA986D0E9.8D1E2BCF-ON8525723E.004DFE6D-8525723E.004F3978@MAIL.DE.FESTO.NET>

First of all, let  me thank you for the great hints.  Especially, the under
the manifold leak, I have been racking my brain on how to check for that
problem.  In regards to the crumbs, hopefully, the new engine, new
manifold, and new EGR valve would not have an issue like this but I have
seen crazy stuff happen before.  I will pull the EGR valve and look for any
obstruction.  I might put the old one back on the engine.  The Map sensor
or vacuum line may be a problem too.  Do you know if the MAP sensor has the
same calibration as a slightly newer unit from a 1993 Chevy Suburban with
TBI.  I own the suburban and it runs fine.  I almost hate to swap parts
because you know what will happen.

The truck sat for two years and I am unaware of the problems it had before
it quit running.  However, after I got the vehicle it fired right up after
replacing the battery and I was able to move it around in the yard, seems
like it cut off some then but the big problem was the engine was so caked
with oil  that the oil on top of the head could not drain back to the pan,
so when the oil reached the height of the valve guide, the oil would push
through to the exhaust on the back two cylinders and it would begin smoking
like a freight train.  Then it would stop smoking and run for awhile
longer.  This was evident from the wet exhaust ports on the heads on
cylinders 7 and 8.

One other thing, I just thought of, is that the Edlebrock Manifold
(EDL-3704) only required 25 ft-lbs or torque to tighten while the manual
said to use 35 ft-lbs of torque.  Maybe I could tighten the intake to 35
ft-lbs to stop a internal leakage after I check the vacuum on the valve
cover.

Regards,

David Thomas
Food & Packaging SBD Engineer
Festo Corporation
Phone: (704) 527-1427
Fax: (704) 527-7935
email: dave.thomas at us.festo.com






                                                                                                                
         "David Allen" <davida1 at hiwaay.net>                         12/08/2006 09:01 AM                         
                                                                                                                



      Please respond to
"David Allen" <davida1 at hiwaay.net>

|--+------------------------>
|  |                        |
|--+------------------------>
  >-----------------------------------------------------------------------------------------------------------------------------------------|
  |                                                                                                                                         |
  |                                                                                                                                         |
  |                                                                                                                                       To|
  |        <gmecm at diy-efi.org>, <Dave.Thomas at us.festo.com>                                                                                  |
  |                                                                                                                                       cc|
  |                                                                                                                                         |
  |                                                                                                                                  Subject|
  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems                                                                              |
  |                                                                                                                                         |
  |                                                                                                                                         |
  |                                                                                                                                         |
  |                                                                                                                                         |
  |                                                                                                                                         |
  >-----------------------------------------------------------------------------------------------------------------------------------------|




  This may have already been addressed but... If the EGR valve pintle (the
piece that closes and opens the exhaust flow) is stuck, even a little, it
will cause similar idle stalling.
  Sometimes the act of changing the EGR valve will dislodge some carbon
from inside the manifold passage.  Then a crumb will immediately hold-open
the new EGR valve. Essentially this is causing a huge internal vacuum leak
betweent he manifold and exhaust.
  Pull the valve and look for any junk in the pintle.
  I guess you have checked for bad intake gaskets?  Pull the PCV valve out
of the valvecover and plug the valvecover hole.  Locate the other
valvecover hole (where the vent hose goes to the air filter) and place your
thumb over it.  If you feel vacuum (in spite of the PCV valve not being
connected) then your intake gaskets may be blown/ torn on the bottom edge,
drawing air from inside the block where the carb-cleaner test will not
catch it.
  Also a slow response from the MAP sensor due to a plugged or collapsed
vacuum hose is devastating to a TBI system. The ECM will not compensate
immediately for changes in air pressure and the engine will run lean or
rich under transient conditions.
  If this was running before the engine was repaced, then likely something
"happened" during the engine remove / install.
  Hope this helps!
David

----- Original Message -----
From: "Dave Thomas" <Dave.Thomas at us.festo.com>
To: <gmecm at diy-efi.org>
Sent: Thursday, December 07, 2006 11:00 PM
Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems


> Here is what I have observed today.  Replace ACSU prom with AMUR prom.
Ran
> pretty good until closed loop mode.  Same problem with stalling when
> putting into gear the second time. (I.E. put vehicle in gear, watch Idle
> air counts go to zero, return to park or neutral, vehicle rpms raise, but
> IAC stays at 0, try to put vehicle back into gear and the vehicle cuts
off.
>
> I cannot for the life of me get the car to run to set the minimum air
idle
> setting which I believe to be 425 rpm +/- 25 rpm, with vehicle in gear.
> This is after I ground the diagnostic pins on the ALDL connector, wait 10
> seconds for the IAC motor to zero out, remove ground from ALDL and start
> engine.  As I turn the idle screw down where the rpm's are around 500
rpm,
> the vehicle just stalls out.  Recrank engine, truck runs fine until you
> place into gear, the IAC counts start counting down, if it stops before
> reaching 0, the car stalls out everytime with the new prom calibration,
> which has idle at operating temp set to 500 rpm.  The old prom ran at 525
> rpm.  I checked the vacuum, at one point the engine was surging up and
down
> and the vacuum gauge was sweeping back and forth between 15" HG and 17"
> HG..  I have a trouble shooting guide which says to look at the ignition
if
> vacuum varies between 1 and 2 " HG.  Can the coil or ignition module be
> heating up and just dropping out at low idle speeds?
>
> I plugged the EGR,AIR vacuum port, the vapor canistor vacuum port and
> plugged my vacuum gauge into the port on the rear fitting of the
manifold.
> This left the PCV valve port, Map port, and vacuum booster connected to
the
> system.  I then squirted TBI cleaner and WD40 around the base of the
> Throttle body, all vacuum lines  and capped ports, fitting where vacuum
> booster is connected to the manifold and no leak has shown.
>
> Also checked the fuel pressure at the outlet of the fuel filter.  It was
> dead nuts on 13 psi.
>
> I'm not sure why I can't get the min. idle air to 400 rpms?  Any
> suggestions?
>
> Once again, Thanks for reading and any suggestions,
>
> David Thomas
> Food & Packaging SBD Engineer
> Festo Corporation
> Phone: (704) 527-1427
> Fax: (704) 527-7935
> email: dave.thomas at us.festo.com
>
>
>
>
>
>
>

>         "Programmer" <lwester at lincsat.com>
12/07/2006 07:39 PM
>

>
>
>
>      Sent by:
>
>      gmecm-bounces at diy-efi.org 12/07/2006 07:38 PM
>
>      Please respond to
> gmecm at diy-efi.org
>
> |--+-------------------------------->
> |  |                                |
> |--+-------------------------------->
>
>--------------------------------------------------------------------------------------------------------------------------------------------------|

>  |
|
>  |
|
>  |
To|
>  |        <gmecm at diy-efi.org>
|
>  |
cc|
>  |
|
>  |
Subject|
>  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
|
>  |
|
>  |
|
>  |
|
>  |
|
>  |
|
>
>--------------------------------------------------------------------------------------------------------------------------------------------------|

>
>
>
>
> Diagnose from the latest calibration first...but your "0" IAC count is
> definitely indicating unmetered or uncontrolled air.
>
> Lyndon.
>
> ----- Original Message -----
> From: "Dave Thomas" <Dave.Thomas at us.festo.com>
> To: <gmecm at diy-efi.org>
> Sent: Thursday, December 07, 2006 8:41 AM
> Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems
>
>
>> PCV Valve - Brand new from GM
>> EGR Valve - Brand new from GM ( I also tried removing the vacuum hose
and
>> plugging the  vac hose to eliminate the switch leaking)
>> I plan on checking the fuel pressure, exhaust backpressure and install
> new
>> AMUR prom.  I am going to try to reset the min. air at idle, and I have
>> diacom that I will try to record some data.  I also plan on rechecking
> the
>> MAP sensor and test the vacuum with a pressure gauge to see if there are
>> any inconsistencies.
>>
>> I have not replaced the fuel pressure regulator, but I would expect the
>> fuel pressure test should show any problems with it.
>>
>> Thanks for your suggestions,
>>
>> David Thomas
>> Food & Packaging SBD Engineer
>> Festo Corporation
>> Phone: (704) 527-1427
>> Fax: (704) 527-7935
>> email: dave.thomas at us.festo.com
>>
>>
>>
>>
>>
>>
>>
>>         "Programmer" <lwester at lincsat.com>
>> 12/07/2006 10:30 AM
>>
>>
>>
>>
>>      Sent by:
>>
>>      gmecm-bounces at diy-efi.org 12/07/2006 10:26 AM
>>
>>      Please respond to
>> gmecm at diy-efi.org
>>
>> |--+------------------------>
>> |  |                        |
>> |--+------------------------>
>>
>>
>>-----------------------------------------------------------------------------------------------------------------------------------------|

>
>>  |
>> |
>>  |
>> |
>>  |
>> To|
>>  |        <gmecm at diy-efi.org>
>> |
>>  |
>> cc|
>>  |
>> |
>>  |
>> Subject|
>>  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
>> |
>>  |
>> |
>>  |
>> |
>>  |
>> |
>>  |
>> |
>>  |
>> |
>>
>>
>>-----------------------------------------------------------------------------------------------------------------------------------------|

>
>>
>>
>>
>>
>> PCV valve correct ?
>> EGR leaking ? (IS this the correct EGR valve from GM ?)
>> The updated PROM ACSU to AKAJ to AMUR had several related TSB's ...and
>> these
>> updates fixed those concerns.
>> TSB 88-180-6E AKAJ
>> TSB 88-T-109
>> TSB 88-T-25
>> TSB 88-87-657-109
>> TSB 88-88-657-108AMUR
>>
>> Lyndon.
>>
>> ----- Original Message -----
>> From: "Dave Thomas" <Dave.Thomas at us.festo.com>
>> To: <gmecm at diy-efi.org>
>> Sent: Tuesday, December 05, 2006 6:34 AM
>> Subject: [Gmecm] SER# 1227747 ACSU promID Idle Problems
>>
>>
>>>
>>>
>>>
>>> I have a 1987 GMC V1500 4WD truck with a 700R4 transmission.  The Prom
> ID
>>> is ACSU.  I have replaced the original engine with a GM Factory Crate
>>> Replacement for VIN K engines.  All stock except for an Edelbrock
>> EDL-3704
>>> manifold.  I am having some problems with the idling of the engine and
>>> stalling when put into gear.  I have noticed on a cold start that
>>> everything seems to be fine with the exception of BLM of ~154.  As the
>>> unit
>>> warms up to temperature, I notice the engine will start to reduce the
>> idle
>>> speed trying for a idle speed of ~625 rpm.  At this point the IAC
counts
>>> are hovering around 40 counts.  When I put the truck in gear, the IAC
>>> counts start reducing along with the rpms until the rpm reaches ~525.
> At
>>> this point, the IAC counts are usually at 0.  When the vehicle is
> shifted
>>> back into park or neutral, the idle will raise back up but the IAC
> counts
>>> will remain at 0.  When the vehicle is put into gear the second time,
> the
>>> engine will stall and die.  I have tried setting the minimum Idle on
the
>>> throttle body to allow the IAC to remain open, however 3-5 counts is
the
>>> best I have ever achieved but this did not correct the stalling.  Also,
> I
>>> have tried the service procedure for checking minimum idle air at 425
>> rpms
>>> in gear with the IAC unplugged.  I cannot achieve this number without
> the
>>> vehicle stalling.  I have sprayed TBI cleaner around the intake
> manifold,
>>> tbi gakset, all vacuum connections and I have not seen the idle raise
>>> showing a vacuum leak.  Also, after stalling the vehicle is very hard
to
>>> start and keep running unless you rev the engine up above 1500 rpm and
>> let
>>> of the throttle very slowly.  Also, occasionally the engine will surge
> up
>>> and down (50-100 rpms) but not too extreme.
>>>
>>> We replaced the rotor, cap, wires, spark plugs, knock sensor, O2
sensor,
>>> new EGR valve, PCV valve,  cleaned the throttle body, and all new
> gaskets
>>> during the engine swap.  The MAP sensor, throttle position sensor,
>>> ignition
>>> module, coil, EGR switch,  are from the old engine.  I have also
swapped
>>> the IAC motor with one that is known to be good with no change.  The
>>> original engine was gunked up and not allowing the oil to flow back
from
>>> the head, after some time of running, oil would enter the exhaust valve
>>> guides on the number 7 and 8 cylinders causing the spark plugs to foul.
>> I
>>> haven't checked the back pressure from the exhaust system/ cat but it
is
>>> suspect.  I also plan to check the Fuel pressure to see if the unit is
>>> functioning within specifications (9-13 psi).  I have ordered an
updated
>>> prom with the bin file AMUR which seems to be the latest eprom however
I
>>> don't  really expect this will fix the problem.
>>>
>>> TPS = 0.66 volts at idle
>>> Map at idle was in spec.
>>>
>>> Everything seems to be working fine but obviously something is not.
>>>
>>> Any information greatly appreciated,
>>>
>>> David Thomas
>>> Food & Packaging SBD Engineer
>>> Festo Corporation
>>> Phone: (704) 527-1427
>>> Fax: (704) 527-7935
>>> email: dave.thomas at us.festo.com
>>>
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>
>>>
>>>
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>>
>>
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>
>
>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>






From davida1 at hiwaay.net  Fri Dec  8 08:40:45 2006
From: davida1 at hiwaay.net (David Allen)
Date: Fri, 8 Dec 2006 08:40:45 -0600
Subject: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
References: <OFA986D0E9.8D1E2BCF-ON8525723E.004DFE6D-8525723E.004F3978@MAIL.DE.FESTO.NET>
Message-ID: <004c01c71ad6$ec72d2a0$0700a8c0@yancey.com>

  OK Didn't know the manifold was new! It shouldn't have carbon in it at all.  Unless the casting is defective and there is a cross-leak in the EGR ports.
  AFAIK the MAP sensors are all the same IF the connector plugged in.  The 1-bar, 2-bar and 3-bar versions are keyed different in the connector.  As far as I know all non-turbo / non-supercharged engines have a standard 1-bar sensor.  So the 93 'Burban sensr should be the same.
  Re-tightening the manifold could very well stop an internal manifold gasket leak, but it could also warp the manifold and cause worse problems.    
  If the ECM is closing the IAC off all the way (down to 0) that tells us the idle is above the target idle RPM.  The only way it can become above the target idle RPM is if there is air entering the engine from some unknown source.
  Have you disconnected abd plugged the brake booster port yet?  It can cause a huge leak that originates under the dash in the car where you can't hear it.
  Maybe when you shift into gear and back to P/N, you hold the brakes then release them.  This causes the booster to do something "wrong" and aggravated the leak?
  Just another crazy thought...
David


----- Original Message ----- 
From: "Dave Thomas" <Dave.Thomas at us.festo.com>
To: <gmecm at diy-efi.org>
Sent: Friday, December 08, 2006 8:25 AM
Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems


> First of all, let  me thank you for the great hints.  Especially, the under
> the manifold leak, I have been racking my brain on how to check for that
> problem.  In regards to the crumbs, hopefully, the new engine, new
> manifold, and new EGR valve would not have an issue like this but I have
> seen crazy stuff happen before.  I will pull the EGR valve and look for any
> obstruction.  I might put the old one back on the engine.  The Map sensor
> or vacuum line may be a problem too.  Do you know if the MAP sensor has the
> same calibration as a slightly newer unit from a 1993 Chevy Suburban with
> TBI.  I own the suburban and it runs fine.  I almost hate to swap parts
> because you know what will happen.
> 
> The truck sat for two years and I am unaware of the problems it had before
> it quit running.  However, after I got the vehicle it fired right up after
> replacing the battery and I was able to move it around in the yard, seems
> like it cut off some then but the big problem was the engine was so caked
> with oil  that the oil on top of the head could not drain back to the pan,
> so when the oil reached the height of the valve guide, the oil would push
> through to the exhaust on the back two cylinders and it would begin smoking
> like a freight train.  Then it would stop smoking and run for awhile
> longer.  This was evident from the wet exhaust ports on the heads on
> cylinders 7 and 8.
> 
> One other thing, I just thought of, is that the Edlebrock Manifold
> (EDL-3704) only required 25 ft-lbs or torque to tighten while the manual
> said to use 35 ft-lbs of torque.  Maybe I could tighten the intake to 35
> ft-lbs to stop a internal leakage after I check the vacuum on the valve
> cover.
> 
> Regards,
> 
> David Thomas
> Food & Packaging SBD Engineer
> Festo Corporation
> Phone: (704) 527-1427
> Fax: (704) 527-7935
> email: dave.thomas at us.festo.com
> 
> 
> 
> 
> 
> 
>                                                                                                                
>         "David Allen" <davida1 at hiwaay.net>                         12/08/2006 09:01 AM                         
>                                                                                                                
> 
> 
> 
>      Please respond to
> "David Allen" <davida1 at hiwaay.net>
> 
> |--+------------------------>
> |  |                        |
> |--+------------------------>
>  >-----------------------------------------------------------------------------------------------------------------------------------------|
>  |                                                                                                                                         |
>  |                                                                                                                                         |
>  |                                                                                                                                       To|
>  |        <gmecm at diy-efi.org>, <Dave.Thomas at us.festo.com>                                                                                  |
>  |                                                                                                                                       cc|
>  |                                                                                                                                         |
>  |                                                                                                                                  Subject|
>  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems                                                                              |
>  |                                                                                                                                         |
>  |                                                                                                                                         |
>  |                                                                                                                                         |
>  |                                                                                                                                         |
>  |                                                                                                                                         |
>  >-----------------------------------------------------------------------------------------------------------------------------------------|
> 
> 
> 
> 
>  This may have already been addressed but... If the EGR valve pintle (the
> piece that closes and opens the exhaust flow) is stuck, even a little, it
> will cause similar idle stalling.
>  Sometimes the act of changing the EGR valve will dislodge some carbon
> from inside the manifold passage.  Then a crumb will immediately hold-open
> the new EGR valve. Essentially this is causing a huge internal vacuum leak
> betweent he manifold and exhaust.
>  Pull the valve and look for any junk in the pintle.
>  I guess you have checked for bad intake gaskets?  Pull the PCV valve out
> of the valvecover and plug the valvecover hole.  Locate the other
> valvecover hole (where the vent hose goes to the air filter) and place your
> thumb over it.  If you feel vacuum (in spite of the PCV valve not being
> connected) then your intake gaskets may be blown/ torn on the bottom edge,
> drawing air from inside the block where the carb-cleaner test will not
> catch it.
>  Also a slow response from the MAP sensor due to a plugged or collapsed
> vacuum hose is devastating to a TBI system. The ECM will not compensate
> immediately for changes in air pressure and the engine will run lean or
> rich under transient conditions.
>  If this was running before the engine was repaced, then likely something
> "happened" during the engine remove / install.
>  Hope this helps!
> David
> 
> ----- Original Message -----
> From: "Dave Thomas" <Dave.Thomas at us.festo.com>
> To: <gmecm at diy-efi.org>
> Sent: Thursday, December 07, 2006 11:00 PM
> Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems
> 
> 
>> Here is what I have observed today.  Replace ACSU prom with AMUR prom.
> Ran
>> pretty good until closed loop mode.  Same problem with stalling when
>> putting into gear the second time. (I.E. put vehicle in gear, watch Idle
>> air counts go to zero, return to park or neutral, vehicle rpms raise, but
>> IAC stays at 0, try to put vehicle back into gear and the vehicle cuts
> off.
>>
>> I cannot for the life of me get the car to run to set the minimum air
> idle
>> setting which I believe to be 425 rpm +/- 25 rpm, with vehicle in gear.
>> This is after I ground the diagnostic pins on the ALDL connector, wait 10
>> seconds for the IAC motor to zero out, remove ground from ALDL and start
>> engine.  As I turn the idle screw down where the rpm's are around 500
> rpm,
>> the vehicle just stalls out.  Recrank engine, truck runs fine until you
>> place into gear, the IAC counts start counting down, if it stops before
>> reaching 0, the car stalls out everytime with the new prom calibration,
>> which has idle at operating temp set to 500 rpm.  The old prom ran at 525
>> rpm.  I checked the vacuum, at one point the engine was surging up and
> down
>> and the vacuum gauge was sweeping back and forth between 15" HG and 17"
>> HG..  I have a trouble shooting guide which says to look at the ignition
> if
>> vacuum varies between 1 and 2 " HG.  Can the coil or ignition module be
>> heating up and just dropping out at low idle speeds?
>>
>> I plugged the EGR,AIR vacuum port, the vapor canistor vacuum port and
>> plugged my vacuum gauge into the port on the rear fitting of the
> manifold.
>> This left the PCV valve port, Map port, and vacuum booster connected to
> the
>> system.  I then squirted TBI cleaner and WD40 around the base of the
>> Throttle body, all vacuum lines  and capped ports, fitting where vacuum
>> booster is connected to the manifold and no leak has shown.
>>
>> Also checked the fuel pressure at the outlet of the fuel filter.  It was
>> dead nuts on 13 psi.
>>
>> I'm not sure why I can't get the min. idle air to 400 rpms?  Any
>> suggestions?
>>
>> Once again, Thanks for reading and any suggestions,
>>
>> David Thomas
>> Food & Packaging SBD Engineer
>> Festo Corporation
>> Phone: (704) 527-1427
>> Fax: (704) 527-7935
>> email: dave.thomas at us.festo.com
>>
>>
>>
>>
>>
>>
>>
> 
>>         "Programmer" <lwester at lincsat.com>
> 12/07/2006 07:39 PM
>>
> 
>>
>>
>>
>>      Sent by:
>>
>>      gmecm-bounces at diy-efi.org 12/07/2006 07:38 PM
>>
>>      Please respond to
>> gmecm at diy-efi.org
>>
>> |--+-------------------------------->
>> |  |                                |
>> |--+-------------------------------->
>>
>>--------------------------------------------------------------------------------------------------------------------------------------------------|
> 
>>  |
> |
>>  |
> |
>>  |
> To|
>>  |        <gmecm at diy-efi.org>
> |
>>  |
> cc|
>>  |
> |
>>  |
> Subject|
>>  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
> |
>>  |
> |
>>  |
> |
>>  |
> |
>>  |
> |
>>  |
> |
>>
>>--------------------------------------------------------------------------------------------------------------------------------------------------|
> 
>>
>>
>>
>>
>> Diagnose from the latest calibration first...but your "0" IAC count is
>> definitely indicating unmetered or uncontrolled air.
>>
>> Lyndon.
>>
>> ----- Original Message -----
>> From: "Dave Thomas" <Dave.Thomas at us.festo.com>
>> To: <gmecm at diy-efi.org>
>> Sent: Thursday, December 07, 2006 8:41 AM
>> Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems
>>
>>
>>> PCV Valve - Brand new from GM
>>> EGR Valve - Brand new from GM ( I also tried removing the vacuum hose
> and
>>> plugging the  vac hose to eliminate the switch leaking)
>>> I plan on checking the fuel pressure, exhaust backpressure and install
>> new
>>> AMUR prom.  I am going to try to reset the min. air at idle, and I have
>>> diacom that I will try to record some data.  I also plan on rechecking
>> the
>>> MAP sensor and test the vacuum with a pressure gauge to see if there are
>>> any inconsistencies.
>>>
>>> I have not replaced the fuel pressure regulator, but I would expect the
>>> fuel pressure test should show any problems with it.
>>>
>>> Thanks for your suggestions,
>>>
>>> David Thomas
>>> Food & Packaging SBD Engineer
>>> Festo Corporation
>>> Phone: (704) 527-1427
>>> Fax: (704) 527-7935
>>> email: dave.thomas at us.festo.com
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>         "Programmer" <lwester at lincsat.com>
>>> 12/07/2006 10:30 AM
>>>
>>>
>>>
>>>
>>>      Sent by:
>>>
>>>      gmecm-bounces at diy-efi.org 12/07/2006 10:26 AM
>>>
>>>      Please respond to
>>> gmecm at diy-efi.org
>>>
>>> |--+------------------------>
>>> |  |                        |
>>> |--+------------------------>
>>>
>>>
>>>-----------------------------------------------------------------------------------------------------------------------------------------|
> 
>>
>>>  |
>>> |
>>>  |
>>> |
>>>  |
>>> To|
>>>  |        <gmecm at diy-efi.org>
>>> |
>>>  |
>>> cc|
>>>  |
>>> |
>>>  |
>>> Subject|
>>>  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
>>> |
>>>  |
>>> |
>>>  |
>>> |
>>>  |
>>> |
>>>  |
>>> |
>>>  |
>>> |
>>>
>>>
>>>-----------------------------------------------------------------------------------------------------------------------------------------|
> 
>>
>>>
>>>
>>>
>>>
>>> PCV valve correct ?
>>> EGR leaking ? (IS this the correct EGR valve from GM ?)
>>> The updated PROM ACSU to AKAJ to AMUR had several related TSB's ...and
>>> these
>>> updates fixed those concerns.
>>> TSB 88-180-6E AKAJ
>>> TSB 88-T-109
>>> TSB 88-T-25
>>> TSB 88-87-657-109
>>> TSB 88-88-657-108AMUR
>>>
>>> Lyndon.
>>>
>>> ----- Original Message -----
>>> From: "Dave Thomas" <Dave.Thomas at us.festo.com>
>>> To: <gmecm at diy-efi.org>
>>> Sent: Tuesday, December 05, 2006 6:34 AM
>>> Subject: [Gmecm] SER# 1227747 ACSU promID Idle Problems
>>>
>>>
>>>>
>>>>
>>>>
>>>> I have a 1987 GMC V1500 4WD truck with a 700R4 transmission.  The Prom
>> ID
>>>> is ACSU.  I have replaced the original engine with a GM Factory Crate
>>>> Replacement for VIN K engines.  All stock except for an Edelbrock
>>> EDL-3704
>>>> manifold.  I am having some problems with the idling of the engine and
>>>> stalling when put into gear.  I have noticed on a cold start that
>>>> everything seems to be fine with the exception of BLM of ~154.  As the
>>>> unit
>>>> warms up to temperature, I notice the engine will start to reduce the
>>> idle
>>>> speed trying for a idle speed of ~625 rpm.  At this point the IAC
> counts
>>>> are hovering around 40 counts.  When I put the truck in gear, the IAC
>>>> counts start reducing along with the rpms until the rpm reaches ~525.
>> At
>>>> this point, the IAC counts are usually at 0.  When the vehicle is
>> shifted
>>>> back into park or neutral, the idle will raise back up but the IAC
>> counts
>>>> will remain at 0.  When the vehicle is put into gear the second time,
>> the
>>>> engine will stall and die.  I have tried setting the minimum Idle on
> the
>>>> throttle body to allow the IAC to remain open, however 3-5 counts is
> the
>>>> best I have ever achieved but this did not correct the stalling.  Also,
>> I
>>>> have tried the service procedure for checking minimum idle air at 425
>>> rpms
>>>> in gear with the IAC unplugged.  I cannot achieve this number without
>> the
>>>> vehicle stalling.  I have sprayed TBI cleaner around the intake
>> manifold,
>>>> tbi gakset, all vacuum connections and I have not seen the idle raise
>>>> showing a vacuum leak.  Also, after stalling the vehicle is very hard
> to
>>>> start and keep running unless you rev the engine up above 1500 rpm and
>>> let
>>>> of the throttle very slowly.  Also, occasionally the engine will surge
>> up
>>>> and down (50-100 rpms) but not too extreme.
>>>>
>>>> We replaced the rotor, cap, wires, spark plugs, knock sensor, O2
> sensor,
>>>> new EGR valve, PCV valve,  cleaned the throttle body, and all new
>> gaskets
>>>> during the engine swap.  The MAP sensor, throttle position sensor,
>>>> ignition
>>>> module, coil, EGR switch,  are from the old engine.  I have also
> swapped
>>>> the IAC motor with one that is known to be good with no change.  The
>>>> original engine was gunked up and not allowing the oil to flow back
> from
>>>> the head, after some time of running, oil would enter the exhaust valve
>>>> guides on the number 7 and 8 cylinders causing the spark plugs to foul.
>>> I
>>>> haven't checked the back pressure from the exhaust system/ cat but it
> is
>>>> suspect.  I also plan to check the Fuel pressure to see if the unit is
>>>> functioning within specifications (9-13 psi).  I have ordered an
> updated
>>>> prom with the bin file AMUR which seems to be the latest eprom however
> I
>>>> don't  really expect this will fix the problem.
>>>>
>>>> TPS = 0.66 volts at idle
>>>> Map at idle was in spec.
>>>>
>>>> Everything seems to be working fine but obviously something is not.
>>>>
>>>> Any information greatly appreciated,
>>>>
>>>> David Thomas
>>>> Food & Packaging SBD Engineer
>>>> Festo Corporation
>>>> Phone: (704) 527-1427
>>>> Fax: (704) 527-7935
>>>> email: dave.thomas at us.festo.com
>>>>
>>>> _______________________________________________
>>>> Gmecm mailing list
>>>> Gmecm at diy-efi.org
>>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Gmecm mailing list
>>>> Gmecm at diy-efi.org
>>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>>
>>
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
> 
> 
> 
> 
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>


From dgilbert78 at juno.com  Fri Dec  8 12:27:35 2006
From: dgilbert78 at juno.com (dgilbert78 at juno.com)
Date: Fri, 8 Dec 2006 13:27:35 -0500
Subject: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
Message-ID: <20061208.132740.-110295.2.dgilbert78@juno.com>

Hello: Have been following your problems a little. The IAC count should
never be at zero, if it gets to zero it will loose control of the idle.
You do want it however to be as low as possible without ever going to
zero. I had a lifter valley leak that was bleeding air into two cylinders
adjacent on Pass side of a 355. The way i discovered this was by pulling
the plugs after engine had been running for awhile. The leaking ports had
more carbon deposited on the plugs than the non leaking ones.(sucking
oil) Cleaned plugs and re installed and after awhile they were carboned
up again. Pulled the intake and the gasket mating surfaces had oil on
them, and should not have had any. Installed new gaskets and a skim of
red RTV. Snugged the intake bolts and beat on the manifold carb flange
with a rubber mallet. Tightened intake bolts a little and beat on it
again. Repeated the process until reached torque specs, this resolved the
problem. Also On the TBI units they have a habit of having the MAP port
carbon up. A vacuum gauge will only show a complete plug. The TBI needs
to be pulled and the MAP vacuum port verified that it is completely open,
use choke cleaner and a rod to make sure all carbon is gone. If the port
is highly restriced it will act like a carbed acclerator pump problem for
the vacuum to the MAP is delayed and lags behind vacuum demand, engine
will hessitate on quick throttle opening. Well hope some of that info
helps you in some small way. Good luck
Darryl...
On Fri, 8 Dec 2006 08:40:45 -0600 "David Allen" <davida1 at hiwaay.net>
writes:
>   OK Didn't know the manifold was new! It shouldn't have carbon in it 
> at all.  Unless the casting is defective and there is a cross-leak 
> in the EGR ports.
>   AFAIK the MAP sensors are all the same IF the connector plugged 
> in.  The 1-bar, 2-bar and 3-bar versions are keyed different in the 
> connector.  As far as I know all non-turbo / non-supercharged 
> engines have a standard 1-bar sensor.  So the 93 'Burban sensr 
> should be the same.
>   Re-tightening the manifold could very well stop an internal 
> manifold gasket leak, but it could also warp the manifold and cause 
> worse problems.    
>   If the ECM is closing the IAC off all the way (down to 0) that 
> tells us the idle is above the target idle RPM.  The only way it can 
> become above the target idle RPM is if there is air entering the 
> engine from some unknown source.
>   Have you disconnected abd plugged the brake booster port yet?  It 
> can cause a huge leak that originates under the dash in the car 
> where you can't hear it.
>   Maybe when you shift into gear and back to P/N, you hold the 
> brakes then release them.  This causes the booster to do something 
> "wrong" and aggravated the leak?
>   Just another crazy thought...
> David
> 
> 
> ----- Original Message ----- 
> From: "Dave Thomas" <Dave.Thomas at us.festo.com>
> To: <gmecm at diy-efi.org>
> Sent: Friday, December 08, 2006 8:25 AM
> Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems
> 
> 
> > First of all, let  me thank you for the great hints.  Especially, 
> the under
> > the manifold leak, I have been racking my brain on how to check 
> for that
> > problem.  In regards to the crumbs, hopefully, the new engine, 
> new
> > manifold, and new EGR valve would not have an issue like this but 
> I have
> > seen crazy stuff happen before.  I will pull the EGR valve and 
> look for any
> > obstruction.  I might put the old one back on the engine.  The Map 
> sensor
> > or vacuum line may be a problem too.  Do you know if the MAP 
> sensor has the
> > same calibration as a slightly newer unit from a 1993 Chevy 
> Suburban with
> > TBI.  I own the suburban and it runs fine.  I almost hate to swap 
> parts
> > because you know what will happen.
> > 
> > The truck sat for two years and I am unaware of the problems it 
> had before
> > it quit running.  However, after I got the vehicle it fired right 
> up after
> > replacing the battery and I was able to move it around in the 
> yard, seems
> > like it cut off some then but the big problem was the engine was 
> so caked
> > with oil  that the oil on top of the head could not drain back to 
> the pan,
> > so when the oil reached the height of the valve guide, the oil 
> would push
> > through to the exhaust on the back two cylinders and it would 
> begin smoking
> > like a freight train.  Then it would stop smoking and run for 
> awhile
> > longer.  This was evident from the wet exhaust ports on the heads 
> on
> > cylinders 7 and 8.
> > 
> > One other thing, I just thought of, is that the Edlebrock 
> Manifold
> > (EDL-3704) only required 25 ft-lbs or torque to tighten while the 
> manual
> > said to use 35 ft-lbs of torque.  Maybe I could tighten the intake 
> to 35
> > ft-lbs to stop a internal leakage after I check the vacuum on the 
> valve
> > cover.
> > 
> > Regards,
> > 
> > David Thomas
> > Food & Packaging SBD Engineer
> > Festo Corporation
> > Phone: (704) 527-1427
> > Fax: (704) 527-7935
> > email: dave.thomas at us.festo.com
> > 
> > 
> > 
> > 
> > 
> > 
> >                                                                    
>                                             
> >         "David Allen" <davida1 at hiwaay.net>                         
> 12/08/2006 09:01 AM                         
> >                                                                    
>                                             
> > 
> > 
> > 
> >      Please respond to
> > "David Allen" <davida1 at hiwaay.net>
> > 
> > |--+------------------------>
> > |  |                        |
> > |--+------------------------>
> >  
>
>------------------------------------------------------------------------
-----------------------------------------------------------------|
> >  |                                                                 
>                                                                      
>    |
> >  |                                                                 
>                                                                      
>    |
> >  |                                                                 
>                                                                      
>  To|
> >  |        <gmecm at diy-efi.org>, <Dave.Thomas at us.festo.com>          
>                                                                      
>    |
> >  |                                                                 
>                                                                      
>  cc|
> >  |                                                                 
>                                                                      
>    |
> >  |                                                                 
>                                                                  
> Subject|
> >  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems      
>                                                                      
>    |
> >  |                                                                 
>                                                                      
>    |
> >  |                                                                 
>                                                                      
>    |
> >  |                                                                 
>                                                                      
>    |
> >  |                                                                 
>                                                                      
>    |
> >  |                                                                 
>                                                                      
>    |
> >  
>
>------------------------------------------------------------------------
-----------------------------------------------------------------|
> > 
> > 
> > 
> > 
> >  This may have already been addressed but... If the EGR valve 
> pintle (the
> > piece that closes and opens the exhaust flow) is stuck, even a 
> little, it
> > will cause similar idle stalling.
> >  Sometimes the act of changing the EGR valve will dislodge some 
> carbon
> > from inside the manifold passage.  Then a crumb will immediately 
> hold-open
> > the new EGR valve. Essentially this is causing a huge internal 
> vacuum leak
> > betweent he manifold and exhaust.
> >  Pull the valve and look for any junk in the pintle.
> >  I guess you have checked for bad intake gaskets?  Pull the PCV 
> valve out
> > of the valvecover and plug the valvecover hole.  Locate the other
> > valvecover hole (where the vent hose goes to the air filter) and 
> place your
> > thumb over it.  If you feel vacuum (in spite of the PCV valve not 
> being
> > connected) then your intake gaskets may be blown/ torn on the 
> bottom edge,
> > drawing air from inside the block where the carb-cleaner test will 
> not
> > catch it.
> >  Also a slow response from the MAP sensor due to a plugged or 
> collapsed
> > vacuum hose is devastating to a TBI system. The ECM will not 
> compensate
> > immediately for changes in air pressure and the engine will run 
> lean or
> > rich under transient conditions.
> >  If this was running before the engine was repaced, then likely 
> something
> > "happened" during the engine remove / install.
> >  Hope this helps!
> > David
> > 
> > ----- Original Message -----
> > From: "Dave Thomas" <Dave.Thomas at us.festo.com>
> > To: <gmecm at diy-efi.org>
> > Sent: Thursday, December 07, 2006 11:00 PM
> > Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems
> > 
> > 
> >> Here is what I have observed today.  Replace ACSU prom with AMUR 
> prom.
> > Ran
> >> pretty good until closed loop mode.  Same problem with stalling 
> when
> >> putting into gear the second time. (I.E. put vehicle in gear, 
> watch Idle
> >> air counts go to zero, return to park or neutral, vehicle rpms 
> raise, but
> >> IAC stays at 0, try to put vehicle back into gear and the vehicle 
> cuts
> > off.
> >>
> >> I cannot for the life of me get the car to run to set the minimum 
> air
> > idle
> >> setting which I believe to be 425 rpm +/- 25 rpm, with vehicle in 
> gear.
> >> This is after I ground the diagnostic pins on the ALDL connector, 
> wait 10
> >> seconds for the IAC motor to zero out, remove ground from ALDL 
> and start
> >> engine.  As I turn the idle screw down where the rpm's are around 
> 500
> > rpm,
> >> the vehicle just stalls out.  Recrank engine, truck runs fine 
> until you
> >> place into gear, the IAC counts start counting down, if it stops 
> before
> >> reaching 0, the car stalls out everytime with the new prom 
> calibration,
> >> which has idle at operating temp set to 500 rpm.  The old prom 
> ran at 525
> >> rpm.  I checked the vacuum, at one point the engine was surging 
> up and
> > down
> >> and the vacuum gauge was sweeping back and forth between 15" HG 
> and 17"
> >> HG..  I have a trouble shooting guide which says to look at the 
> ignition
> > if
> >> vacuum varies between 1 and 2 " HG.  Can the coil or ignition 
> module be
> >> heating up and just dropping out at low idle speeds?
> >>
> >> I plugged the EGR,AIR vacuum port, the vapor canistor vacuum port 
> and
> >> plugged my vacuum gauge into the port on the rear fitting of the
> > manifold.
> >> This left the PCV valve port, Map port, and vacuum booster 
> connected to
> > the
> >> system.  I then squirted TBI cleaner and WD40 around the base of 
> the
> >> Throttle body, all vacuum lines  and capped ports, fitting where 
> vacuum
> >> booster is connected to the manifold and no leak has shown.
> >>
> >> Also checked the fuel pressure at the outlet of the fuel filter.  
> It was
> >> dead nuts on 13 psi.
> >>
> >> I'm not sure why I can't get the min. idle air to 400 rpms?  Any
> >> suggestions?
> >>
> >> Once again, Thanks for reading and any suggestions,
> >>
> >> David Thomas
> >> Food & Packaging SBD Engineer
> >> Festo Corporation
> >> Phone: (704) 527-1427
> >> Fax: (704) 527-7935
> >> email: dave.thomas at us.festo.com
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> > 
> >>         "Programmer" <lwester at lincsat.com>
> > 12/07/2006 07:39 PM
> >>
> > 
> >>
> >>
> >>
> >>      Sent by:
> >>
> >>      gmecm-bounces at diy-efi.org 12/07/2006 07:38 PM
> >>
> >>      Please respond to
> >> gmecm at diy-efi.org
> >>
> >> |--+-------------------------------->
> >> |  |                                |
> >> |--+-------------------------------->
> >>
>
>>-----------------------------------------------------------------------
-------------------------------------------------------------------------
--|
> > 
> >>  |
> > |
> >>  |
> > |
> >>  |
> > To|
> >>  |        <gmecm at diy-efi.org>
> > |
> >>  |
> > cc|
> >>  |
> > |
> >>  |
> > Subject|
> >>  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
> > |
> >>  |
> > |
> >>  |
> > |
> >>  |
> > |
> >>  |
> > |
> >>  |
> > |
> >>
>
>>-----------------------------------------------------------------------
-------------------------------------------------------------------------
--|
> > 
> >>
> >>
> >>
> >>
> >> Diagnose from the latest calibration first...but your "0" IAC 
> count is
> >> definitely indicating unmetered or uncontrolled air.
> >>
> >> Lyndon.
> >>
> >> ----- Original Message -----
> >> From: "Dave Thomas" <Dave.Thomas at us.festo.com>
> >> To: <gmecm at diy-efi.org>
> >> Sent: Thursday, December 07, 2006 8:41 AM
> >> Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems
> >>
> >>
> >>> PCV Valve - Brand new from GM
> >>> EGR Valve - Brand new from GM ( I also tried removing the vacuum 
> hose
> > and
> >>> plugging the  vac hose to eliminate the switch leaking)
> >>> I plan on checking the fuel pressure, exhaust backpressure and 
> install
> >> new
> >>> AMUR prom.  I am going to try to reset the min. air at idle, and 
> I have
> >>> diacom that I will try to record some data.  I also plan on 
> rechecking
> >> the
> >>> MAP sensor and test the vacuum with a pressure gauge to see if 
> there are
> >>> any inconsistencies.
> >>>
> >>> I have not replaced the fuel pressure regulator, but I would 
> expect the
> >>> fuel pressure test should show any problems with it.
> >>>
> >>> Thanks for your suggestions,
> >>>
> >>> David Thomas
> >>> Food & Packaging SBD Engineer
> >>> Festo Corporation
> >>> Phone: (704) 527-1427
> >>> Fax: (704) 527-7935
> >>> email: dave.thomas at us.festo.com
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>         "Programmer" <lwester at lincsat.com>
> >>> 12/07/2006 10:30 AM
> >>>
> >>>
> >>>
> >>>
> >>>      Sent by:
> >>>
> >>>      gmecm-bounces at diy-efi.org 12/07/2006 10:26 AM
> >>>
> >>>      Please respond to
> >>> gmecm at diy-efi.org
> >>>
> >>> |--+------------------------>
> >>> |  |                        |
> >>> |--+------------------------>
> >>>
> >>>
>
>>>----------------------------------------------------------------------
-------------------------------------------------------------------|
> > 
> >>
> >>>  |
> >>> |
> >>>  |
> >>> |
> >>>  |
> >>> To|
> >>>  |        <gmecm at diy-efi.org>
> >>> |
> >>>  |
> >>> cc|
> >>>  |
> >>> |
> >>>  |
> >>> Subject|
> >>>  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
> >>> |
> >>>  |
> >>> |
> >>>  |
> >>> |
> >>>  |
> >>> |
> >>>  |
> >>> |
> >>>  |
> >>> |
> >>>
> >>>
>
>>>----------------------------------------------------------------------
-------------------------------------------------------------------|
> > 
> >>
> >>>
> >>>
> >>>
> >>>
> >>> PCV valve correct ?
> >>> EGR leaking ? (IS this the correct EGR valve from GM ?)
> >>> The updated PROM ACSU to AKAJ to AMUR had several related TSB's 
> ...and
> >>> these
> >>> updates fixed those concerns.
> >>> TSB 88-180-6E AKAJ
> >>> TSB 88-T-109
> >>> TSB 88-T-25
> >>> TSB 88-87-657-109
> >>> TSB 88-88-657-108AMUR
> >>>
> >>> Lyndon.
> >>>
> >>> ----- Original Message -----
> >>> From: "Dave Thomas" <Dave.Thomas at us.festo.com>
> >>> To: <gmecm at diy-efi.org>
> >>> Sent: Tuesday, December 05, 2006 6:34 AM
> >>> Subject: [Gmecm] SER# 1227747 ACSU promID Idle Problems
> >>>
> >>>
> >>>>
> >>>>
> >>>>
> >>>> I have a 1987 GMC V1500 4WD truck with a 700R4 transmission.  
> The Prom
> >> ID
> >>>> is ACSU.  I have replaced the original engine with a GM Factory 
> Crate
> >>>> Replacement for VIN K engines.  All stock except for an 
> Edelbrock
> >>> EDL-3704
> >>>> manifold.  I am having some problems with the idling of the 
> engine and
> >>>> stalling when put into gear.  I have noticed on a cold start 
> that
> >>>> everything seems to be fine with the exception of BLM of ~154.  
> As the
> >>>> unit
> >>>> warms up to temperature, I notice the engine will start to 
> reduce the
> >>> idle
> >>>> speed trying for a idle speed of ~625 rpm.  At this point the 
> IAC
> > counts
> >>>> are hovering around 40 counts.  When I put the truck in gear, 
> the IAC
> >>>> counts start reducing along with the rpms until the rpm reaches 
> ~525.
> >> At
> >>>> this point, the IAC counts are usually at 0.  When the vehicle 
> is
> >> shifted
> >>>> back into park or neutral, the idle will raise back up but the 
> IAC
> >> counts
> >>>> will remain at 0.  When the vehicle is put into gear the second 
> time,
> >> the
> >>>> engine will stall and die.  I have tried setting the minimum 
> Idle on
> > the
> >>>> throttle body to allow the IAC to remain open, however 3-5 
> counts is
> > the
> >>>> best I have ever achieved but this did not correct the 
> stalling.  Also,
> >> I
> >>>> have tried the service procedure for checking minimum idle air 
> at 425
> >>> rpms
> >>>> in gear with the IAC unplugged.  I cannot achieve this number 
> without
> >> the
> >>>> vehicle stalling.  I have sprayed TBI cleaner around the 
> intake
> >> manifold,
> >>>> tbi gakset, all vacuum connections and I have not seen the idle 
> raise
> >>>> showing a vacuum leak.  Also, after stalling the vehicle is 
> very hard
> > to
> >>>> start and keep running unless you rev the engine up above 1500 
> rpm and
> >>> let
> >>>> of the throttle very slowly.  Also, occasionally the engine 
> will surge
> >> up
> >>>> and down (50-100 rpms) but not too extreme.
> >>>>
> >>>> We replaced the rotor, cap, wires, spark plugs, knock sensor, 
> O2
> > sensor,
> >>>> new EGR valve, PCV valve,  cleaned the throttle body, and all 
> new
> >> gaskets
> >>>> during the engine swap.  The MAP sensor, throttle position 
> sensor,
> >>>> ignition
> >>>> module, coil, EGR switch,  are from the old engine.  I have 
> also
> > swapped
> >>>> the IAC motor with one that is known to be good with no change. 
>  The
> >>>> original engine was gunked up and not allowing the oil to flow 
> back
> > from
> >>>> the head, after some time of running, oil would enter the 
> exhaust valve
> >>>> guides on the number 7 and 8 cylinders causing the spark plugs 
> to foul.
> >>> I
> >>>> haven't checked the back pressure from the exhaust system/ cat 
> but it
> > is
> >>>> suspect.  I also plan to check the Fuel pressure to see if the 
> unit is
> >>>> functioning within specifications (9-13 psi).  I have ordered 
> an
> > updated
> >>>> prom with the bin file AMUR which seems to be the latest eprom 
> however
> > I
> >>>> don't  really expect this will fix the problem.
> >>>>
> >>>> TPS = 0.66 volts at idle
> >>>> Map at idle was in spec.
> >>>>
> >>>> Everything seems to be working fine but obviously something is 
> not.
> >>>>
> >>>> Any information greatly appreciated,
> >>>>
> >>>> David Thomas
> >>>> Food & Packaging SBD Engineer
> >>>> Festo Corporation
> >>>> Phone: (704) 527-1427
> >>>> Fax: (704) 527-7935
> >>>> email: dave.thomas at us.festo.com
> >>>>
> >>>> _______________________________________________
> >>>> Gmecm mailing list
> >>>> Gmecm at diy-efi.org
> >>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> >>>> Main WWW page: http://www.diy-efi.org/gmecm
> >>>>
> >>>>
> >>>>
> >>>> _______________________________________________
> >>>> Gmecm mailing list
> >>>> Gmecm at diy-efi.org
> >>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> >>>> Main WWW page: http://www.diy-efi.org/gmecm
> >>>
> >>> _______________________________________________
> >>> Gmecm mailing list
> >>> Gmecm at diy-efi.org
> >>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> >>> Main WWW page: http://www.diy-efi.org/gmecm
> >>>
> >>>
> >>>
> >>>
> >>> _______________________________________________
> >>> Gmecm mailing list
> >>> Gmecm at diy-efi.org
> >>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> >>> Main WWW page: http://www.diy-efi.org/gmecm
> >>
> >> _______________________________________________
> >> Gmecm mailing list
> >> Gmecm at diy-efi.org
> >> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> >> Main WWW page: http://www.diy-efi.org/gmecm
> >>
> >>
> >>
> >>
> >> _______________________________________________
> >> Gmecm mailing list
> >> Gmecm at diy-efi.org
> >> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> >> Main WWW page: http://www.diy-efi.org/gmecm
> >>
> > 
> > 
> > 
> > 
> > _______________________________________________
> > Gmecm mailing list
> > Gmecm at diy-efi.org
> > Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> > Main WWW page: http://www.diy-efi.org/gmecm
> >
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 
> 


From jay at vessels-clan.com  Fri Dec  8 18:01:37 2006
From: jay at vessels-clan.com (Jay Vessels)
Date: Fri, 08 Dec 2006 19:01:37 -0500
Subject: [Gmecm] SER# 1227747 ACSU promID  Idle Problems
In-Reply-To: <OF7616DBE2.FC4D5A02-ON8525723E.001A2A4E-8525723E.001B8C70@MAIL.DE.FESTO.NET>
References: <OF7616DBE2.FC4D5A02-ON8525723E.001A2A4E-8525723E.001B8C70@MAIL.DE.FESTO.NET>
Message-ID: <4579FCE1.3000507@vessels-clan.com>

Hi there!

> This is after I ground the diagnostic pins on the ALDL connector, wait 10
> seconds for the IAC motor to zero out, remove ground from ALDL and start
> engine.  

This may not be the same on all TBI systems, but I don't think that's 
the right procedure for your system.  Except for my '84 Cavalier (which 
used a rubber plug installed in the TBI) all of the ones I've tuned use 
a somewhat different procedure than you describe.

The difference from what you described is that you *don't* remove the 
ground from the ALDL port before starting.  Leave it there.  Otherwise, 
the ECM will try to control the idle, and you're fighting it with the 
throttle stop screw.

Essentially:
1)  Key off, jumper pins A&B on ALDL.
2)  Key on, adjust TPS to proper voltage (0.5V on the ones I've touched, 
yours may be different?)
2a)  You may want to unplug the IAC, ensuring the ECM doesn't move the 
IAC pintle, but leaving pins Z&B jumpered should do this.
3)  Start engine and let it stabilize.
4)  Adjust idle speed to spec.
5)  Readjust TPS to spec.
6)  Repeat 4 and 5 until both are satisfied.
7)  Shut engine off, remove jumper, and reconnect IAC if unplugged.

Jay Vessels
1982 Chevrolet S-10 Sport, 2.8V6 TBI
1984 Chevrolet S-10 Blazer Sport, 2.8V6 (TBI pending)


From davesnothereman at netscape.net  Sun Dec 10 14:28:58 2006
From: davesnothereman at netscape.net (davesnothereman at netscape.net)
Date: Sun, 10 Dec 2006 15:28:58 -0500
Subject: [Gmecm] Stives, and the 2.8l EFE grid
In-Reply-To: <20061205032901.38303.qmail@web34304.mail.mud.yahoo.com>
References: <20061205032901.38303.qmail@web34304.mail.mud.yahoo.com>
Message-ID: <8C8EAB0F488ED73-434-C91E@MBLK-M02.sysops.aol.com>

 
 The EFE grid is in place for emissions.  When the grid fails electrically, it no longer heats up when commanded.  At this point, it (the grid, not the carb) is susceptible to icing, which will restrict the amount of air allowed into the engine.  With the grid removed, there's little opportunity for it to impede airflow even if frozen in a block of ice.  You could try experimenting with a new grid installed and left disconnected.
 
I played around with screens and heaters under carbs for a few years and I can tell you that warmed intake air can be critical to ice free operation.
 
Zaphod




 Stives, and the 2.8l EFE grid


Hello folks,
I'm not sure what conditions would cause icing in some
2.8s and not others, but I bought my 2.8 with a carb,
and I heard about how the ceramic comes off the grid
(mine was 20% gone when I looked).  I subsequently
removed the grid entirely, and had no problems driving
on extended ski trips through the Rockies, Idaho, and
up and down the Coast to Whistler and Vancouver's
local mountains.  Over 10 years, altitude, humidity,
and -26 deg temps over the Coquihalla (5,500 feet
highway) to ski in the interior have never caused any
problems.  Maybe the lower engine compartment profile
of the Cherokee (compared to a Blazer) keeps the carb
warmer?

Two winters in, I'm also having no problems with my
unheated Fiero throttle body now on the same engine -
no problems yet, even after a few ski trips to the
interior (3000 ft, -20).

I have experienced icing in an aircraft carb - not
fun!  But not in a car yet...

I doubt stoves make much difference to icing, and I
know the EFE grid was useless (and restrictive!) in my
Jeep!

Just my two cents. :)

**********************END TRANSMISSION**********************


 
____________________________________________________________________________________
Have a burning question?  
Go to www.Answers.yahoo.com and get answers from real people who know.
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm
________________________________________________________________________
Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading spam and email virus protection.


From captain_krill at yahoo.com  Mon Dec 11 19:32:49 2006
From: captain_krill at yahoo.com (Cowen)
Date: Mon, 11 Dec 2006 17:32:49 -0800 (PST)
Subject: [Gmecm] Re: Stives, and the 2.8l EFE grid
Message-ID: <409659.50704.qm@web34302.mail.mud.yahoo.com>

Hello Zaphod,

I ran that 2.8 with the broken EFE grid for a few
years of ski trips and didn't have any noticeable
problem, but I had a functioning stove setup.  The
icing I've witnessed with aircraft caused noticeable
power loss and missing ( early spring day, 3,000
feet)- I was glad to be in an accompanying plane!  We
had identical engines, but one was unshrouded and it
iced.  Maybe the smaller engine compartment of the
Cherokee, and the functioning stove were enough to
prevent icing?  I know that the partial vacuum of the
venturi lowers intake charge temps, and the
evaporation of the fuel lowers charge temperature
more, and the vacuum encourages ice deposition, but I
still haven't personally noticed any problems on any
land vehicle.  It's amazing how different all of our
experiences are, with basically the same bits and
pieces!  

On a more "fuel injected" note, I've run across
threads advocating disconnecting the coolant lines to
the throttle body (on a Cavalier site and a Toyota
22RE site).  The idea is to slightly reduce intake
charge temperature. I had to delete the lines to my
Fiero TB in order to make it fit on backwards.  So,
I'm wondering if the water for the TBs is for ice
prevention, or if it's for emissions?

Does multiport even ice, with no venturi and no
evaporation in the TB?

Just musing!

Cowen

**********************END TRANSMISSION**********************


 
____________________________________________________________________________________
Need a quick answer? Get one in minutes from people who know.
Ask your question on www.Answers.yahoo.com


From captain_krill at yahoo.com  Mon Dec 11 19:55:32 2006
From: captain_krill at yahoo.com (Cowen)
Date: Mon, 11 Dec 2006 17:55:32 -0800 (PST)
Subject: [Gmecm] Tracker TBI
Message-ID: <512653.43585.qm@web34312.mail.mud.yahoo.com>

Hello all, I have a mystery, with a Pontiac Asuna
Sunrunner (Chevy Tracker).  It started quite abruptly
in August....

My wife has the 1.6l TBI engine, and it fails
emissions with only high CO.  Looking at the graphs of
emissions over time, it spikes super high every time
the tester accelerates during the road test - then
it's fine  all other times.  That seems to indicate
running rich on Accel.

I also noticed last week we had a day down to -11
Celsius, and when I started it, it was so rich it ran
on 3 cylinders for 10 seconds - then it went to four,
as normal.  I'm guessing it was very rich in open
loop, then when the HO2S warmed up, it was fine.

It also has a mild "bog" coming off idle - just like
when it spikes the CO on acceleration in the emissions
test.

Finally, mileage is down from around 30 MPG to around
20 MPG.

So, that's what's wrong.  Seems to be running rich!!

My mom has the same car, year and even color!  So I've
switched known good parts from hers.  Hers still runs
great, my wife's doesn't.  Here's what I've done:

New Plugs.
Cleaned air filter.
Cleaner EGR.
Set the valves.
All engine compartment grounds have been sanded clean,
Nev-R-Sezed, reassembled.

Swapped the following from mom's good runner:
-cap, wires, rotor
-HO2 sensor
-TPS
-MAP


I also inspected the O-Rings on the injector(it was
immaculate), set the timing, the TB is very clean
inside, the compression is good and even, the coolant
level is up (those cars are very sensitive to that
we've found), can't find any vacuum leaks, PCV is
clean and sealing, charcoal cannister is clean and
dry.  I watched the fuel spray from the injector with
a strobe light - looked even and misty.  No dribbles
when I shut off the engine.  Vacuum line to the
pressure regulator is clear and solid.

So, I'm guessing it's rich in open loop.  What can
cause that to happen suddenly, in a totally stock
vehicle with no messing around??  Thanks for any
guesses!

Duncan


 
____________________________________________________________________________________
Cheap talk?
Check out Yahoo! Messenger's low PC-to-Phone call rates.
http://voice.yahoo.com


From dunvegan at sbcglobal.net  Mon Dec 11 21:31:36 2006
From: dunvegan at sbcglobal.net (Rick McLeod)
Date: Mon, 11 Dec 2006 19:31:36 -0800 (PST)
Subject: [Gmecm] Tracker TBI
Message-ID: <20061212033139.98276.qmail@web80507.mail.yahoo.com>

Run a couple tanks w/ Chevron Techron in the fuel, it sounds as if you have a leaking squirter (injector) which would cause pig rich conditions and stumble off idle, been there, done that, got the Techron rebate checks to prove it.

This is a classic symptom/problem at emissions test time.


----- Original Message ----
From: Cowen <captain_krill at yahoo.com>
To: gmecm at diy-efi.org
Sent: Monday, December 11, 2006 7:55:32 PM
Subject: [Gmecm] Tracker TBI


Hello all, I have a mystery, with a Pontiac Asuna
Sunrunner (Chevy Tracker).  It started quite abruptly
in August....

My wife has the 1.6l TBI engine, and it fails
emissions with only high CO.  Looking at the graphs of
emissions over time, it spikes super high every time
the tester accelerates during the road test - then
it's fine  all other times.  That seems to indicate
running rich on Accel.

I also noticed last week we had a day down to -11
Celsius, and when I started it, it was so rich it ran
on 3 cylinders for 10 seconds - then it went to four,
as normal.  I'm guessing it was very rich in open
loop, then when the HO2S warmed up, it was fine.

It also has a mild "bog" coming off idle - just like
when it spikes the CO on acceleration in the emissions
test.

Finally, mileage is down from around 30 MPG to around
20 MPG.

So, that's what's wrong.  Seems to be running rich!!

My mom has the same car, year and even color!  So I've
switched known good parts from hers.  Hers still runs
great, my wife's doesn't.  Here's what I've done:

New Plugs.
Cleaned air filter.
Cleaner EGR.
Set the valves.
All engine compartment grounds have been sanded clean,
Nev-R-Sezed, reassembled.

Swapped the following from mom's good runner:
-cap, wires, rotor
-HO2 sensor
-TPS
-MAP


I also inspected the O-Rings on the injector(it was
immaculate), set the timing, the TB is very clean
inside, the compression is good and even, the coolant
level is up (those cars are very sensitive to that
we've found), can't find any vacuum leaks, PCV is
clean and sealing, charcoal cannister is clean and
dry.  I watched the fuel spray from the injector with
a strobe light - looked even and misty.  No dribbles
when I shut off the engine.  Vacuum line to the
pressure regulator is clear and solid.

So, I'm guessing it's rich in open loop.  What can
cause that to happen suddenly, in a totally stock
vehicle with no messing around??  Thanks for any
guesses!

Duncan



____________________________________________________________________________________
Cheap talk?
Check out Yahoo! Messenger's low PC-to-Phone call rates.
http://voice.yahoo.com
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm

From dgilbert78 at juno.com  Mon Dec 11 22:30:40 2006
From: dgilbert78 at juno.com (dgilbert78 at juno.com)
Date: Mon, 11 Dec 2006 23:30:40 -0500
Subject: [Gmecm] Tracker TBI
Message-ID: <20061211.233041.-246959.0.dgilbert78@juno.com>

Hello: two things come to mind, but possibly not your problem. Poor accel
off Idle could be delayed vacuum to MAP. By this i mean the ported vacuum
to the MAP sensor has become plugged to the point that is no more than a
pin hole, this will delay vacuum to the MAP and cause stumble when
acclerator pedal is advanced. Another thing also comes to mind, weak
spark, Weak spark will drive you absolutely nuts. Get one of those
adjustable el cheapo spark energy testers and see what the output is.
Good luck, hope that helps
Darryl..
On Mon, 11 Dec 2006 17:55:32 -0800 (PST) Cowen <captain_krill at yahoo.com>
writes:
> Hello all, I have a mystery, with a Pontiac Asuna
> Sunrunner (Chevy Tracker).  It started quite abruptly
> in August....
> 
> My wife has the 1.6l TBI engine, and it fails
> emissions with only high CO.  Looking at the graphs of
> emissions over time, it spikes super high every time
> the tester accelerates during the road test - then
> it's fine  all other times.  That seems to indicate
> running rich on Accel.
> 
> I also noticed last week we had a day down to -11
> Celsius, and when I started it, it was so rich it ran
> on 3 cylinders for 10 seconds - then it went to four,
> as normal.  I'm guessing it was very rich in open
> loop, then when the HO2S warmed up, it was fine.
> 
> It also has a mild "bog" coming off idle - just like
> when it spikes the CO on acceleration in the emissions
> test.
> 
> Finally, mileage is down from around 30 MPG to around
> 20 MPG.
> 
> So, that's what's wrong.  Seems to be running rich!!
> 
> My mom has the same car, year and even color!  So I've
> switched known good parts from hers.  Hers still runs
> great, my wife's doesn't.  Here's what I've done:
> 
> New Plugs.
> Cleaned air filter.
> Cleaner EGR.
> Set the valves.
> All engine compartment grounds have been sanded clean,
> Nev-R-Sezed, reassembled.
> 
> Swapped the following from mom's good runner:
> -cap, wires, rotor
> -HO2 sensor
> -TPS
> -MAP
> 
> 
> I also inspected the O-Rings on the injector(it was
> immaculate), set the timing, the TB is very clean
> inside, the compression is good and even, the coolant
> level is up (those cars are very sensitive to that
> we've found), can't find any vacuum leaks, PCV is
> clean and sealing, charcoal cannister is clean and
> dry.  I watched the fuel spray from the injector with
> a strobe light - looked even and misty.  No dribbles
> when I shut off the engine.  Vacuum line to the
> pressure regulator is clear and solid.
> 
> So, I'm guessing it's rich in open loop.  What can
> cause that to happen suddenly, in a totally stock
> vehicle with no messing around??  Thanks for any
> guesses!
> 
> Duncan
> 
> 
>  
>
_________________________________________________________________________
___________
> Cheap talk?
> Check out Yahoo! Messenger's low PC-to-Phone call rates.
> http://voice.yahoo.com
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 
> 


From galaxiecustom500 at sbcglobal.net  Tue Dec 12 00:35:03 2006
From: galaxiecustom500 at sbcglobal.net (Jason McNamara)
Date: Mon, 11 Dec 2006 22:35:03 -0800 (PST)
Subject: [Gmecm] Tracker TBI
In-Reply-To: <512653.43585.qm@web34312.mail.mud.yahoo.com>
Message-ID: <20061212063503.54923.qmail@web81203.mail.mud.yahoo.com>

First thing that comes to my mind is the coolant temperature sensor.  Usually when they fail the computer thinks the engine is colder so adds more fuel.  
   
  I've had problems like that with many cars, although not as bad.  rough running in open loop, sluggish.  Hook up the scan tool and see 10-15 degree lower temp from the sender then what the engine is at, pop in a new coolant temp sensor and no problem.
   
  Worst I ever saw a CTS fail was on the formula sae car at school.  We had problems with it flooding out while trying to start it.  Hooked the lap top up to it, the ecu thought the engine was at -200F in the middle of summer in Ohio.  Since we were out testing about 30 miles from the nearest parts store we just reset some of the cold start values to get it running.  Of course it wouldn't run right after that (bogging, lack of power) so we reconfigured the ecu to ignore the CTS while running, just had it use throttle position and MAP.
   
   
  Cowen <captain_krill at yahoo.com> wrote:
    
I also noticed last week we had a day down to -11
Celsius, and when I started it, it was so rich it ran
on 3 cylinders for 10 seconds - then it went to four,
as normal. I'm guessing it was very rich in open
loop, then when the HO2S warmed up, it was fine.
--------------
  So, I'm guessing it's rich in open loop. What can
cause that to happen suddenly, in a totally stock
vehicle with no messing around?? Thanks for any
guesses!

Duncan



From Pat.Ford at nrc-cnrc.gc.ca  Tue Dec 12 07:25:45 2006
From: Pat.Ford at nrc-cnrc.gc.ca (Ford, Pat)
Date: Tue, 12 Dec 2006 08:25:45 -0500
Subject: [Gmecm] Tracker TBI
In-Reply-To: <20061212063503.54923.qmail@web81203.mail.mud.yahoo.com>
Message-ID: <626E1206D3466344A57EB7A268D4587F046B94A5@nrccenexb4.nrc.ca>

You didn't mention the year of the tracker but if it is anything up to
~94, pull the ecm and check for bad caps, that was the first warning
sign 4 ecms gave me before the caps crashed the ecm. The godd news the
caps are easy to change.
Pat 

-----Original Message-----
From: gmecm-bounces at diy-efi.org [mailto:gmecm-bounces at diy-efi.org] On
Behalf Of Jason McNamara
Sent: Tuesday, December 12, 2006 1:35 AM
To: gmecm at diy-efi.org
Subject: Re: [Gmecm] Tracker TBI

First thing that comes to my mind is the coolant temperature sensor.
Usually when they fail the computer thinks the engine is colder so adds
more fuel.  
   
  I've had problems like that with many cars, although not as bad.
rough running in open loop, sluggish.  Hook up the scan tool and see
10-15 degree lower temp from the sender then what the engine is at, pop
in a new coolant temp sensor and no problem.
   
  Worst I ever saw a CTS fail was on the formula sae car at school.  We
had problems with it flooding out while trying to start it.  Hooked the
lap top up to it, the ecu thought the engine was at -200F in the middle
of summer in Ohio.  Since we were out testing about 30 miles from the
nearest parts store we just reset some of the cold start values to get
it running.  Of course it wouldn't run right after that (bogging, lack
of power) so we reconfigured the ecu to ignore the CTS while running,
just had it use throttle position and MAP.
   
   
  Cowen <captain_krill at yahoo.com> wrote:
    
I also noticed last week we had a day down to -11 Celsius, and when I
started it, it was so rich it ran on 3 cylinders for 10 seconds - then
it went to four, as normal. I'm guessing it was very rich in open loop,
then when the HO2S warmed up, it was fine.
--------------
  So, I'm guessing it's rich in open loop. What can cause that to happen
suddenly, in a totally stock vehicle with no messing around?? Thanks for
any guesses!

Duncan

_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm


From jryan at caminofx.org  Tue Dec 12 08:02:18 2006
From: jryan at caminofx.org (jryan at caminofx.org)
Date: Tue, 12 Dec 2006 08:02:18 -0600
Subject: [Gmecm] Idle Speed
Message-ID: <20061212080218.5pfdsnpz68c0kk0k@webmail.caminofx.org>

I have a new GM long-block 350 with a throttle body from a Camaro and  
an Edelbrock 3704 intake manifold.  The ECM is a 1228746, and I am  
using an ANLU PROM from an '89 9C1 Caprice.

All in all, the combination runs well, but I am curious about something.

I went through the minimum idle speed procedure when the weather was  
relatively cold (in the 40s F daytime).  I got it to idle slow but  
smooth, around the speed set in the ECM constants table in the PROM,  
about 560 RPM or so.

Lately, the weather has warmed up some (to the mid-70s F daytime), and  
the engine seems to idle faster.  It was idling at around 800 RPM when  
I shut off the engine after getting home from work yesterday, and when  
I parked at work this morning.

Watching the temperature gauge in the dashboard, it seems like, to a  
point, it idles faster as the engine temperature increases.  I don't  
see any values in the PROM that would do this, but I may have  
overlooked something.  Is this normal, or should I look for something  
wrong?

For what it's worth, the Camaro throttle body does not have an  
adjustable TPS.  It just screws on.  You can't move it.

On Saturday, I hooked up my laptop with WinALDL while it was idling  
relatively fast, and it showed about 20 IAC counts, so it would appear  
there isn't an uncontrolled vacuum leak.

Is this a sign of something wrong, something I can tune out with a  
laptop or a scantool, or just the way it's programmed?

I know the idle speed is supposed to increase with the A/C compressor  
clutch engaged, and I see that value in the PROM.  That is not a  
factor in this, though, as it has been so cold I have not needed the  
A/C.  I used it for the first time in a month yesterday, and that was  
for defrost because my windshield fogged up.

Every time I have plugged a laptop into it while it's idling in Park,  
no matter the idle speed, the Park/Neutral flag is set, like it's  
supposed to be.

Any hints will be appreciated.



From dunvegan at sbcglobal.net  Tue Dec 12 10:06:28 2006
From: dunvegan at sbcglobal.net (Rick McLeod)
Date: Tue, 12 Dec 2006 08:06:28 -0800 (PST)
Subject: [Gmecm] Idle Speed
Message-ID: <20061212160629.62056.qmail@web80508.mail.yahoo.com>

It would be nice to know the iac count when both cold/slow and warm/fast, to determine if it is being 'commanded' to idle faster, or not, or is it faster because of minimum idle eficiency at temp because it is burning better warm than cold and it's at minimum iac control?

more data, please

cheers


----- Original Message ----
From: "jryan at caminofx.org" <jryan at caminofx.org>
To: gmecm at diy-efi.org
Sent: Tuesday, December 12, 2006 8:02:18 AM
Subject: [Gmecm] Idle Speed


I have a new GM long-block 350 with a throttle body from a Camaro and  
an Edelbrock 3704 intake manifold.  The ECM is a 1228746, and I am  
using an ANLU PROM from an '89 9C1 Caprice.

All in all, the combination runs well, but I am curious about something.

I went through the minimum idle speed procedure when the weather was  
relatively cold (in the 40s F daytime).  I got it to idle slow but  
smooth, around the speed set in the ECM constants table in the PROM,  
about 560 RPM or so.

Lately, the weather has warmed up some (to the mid-70s F daytime), and  
the engine seems to idle faster.  It was idling at around 800 RPM when  
I shut off the engine after getting home from work yesterday, and when  
I parked at work this morning.

Watching the temperature gauge in the dashboard, it seems like, to a  
point, it idles faster as the engine temperature increases.  I don't  
see any values in the PROM that would do this, but I may have  
overlooked something.  Is this normal, or should I look for something  
wrong?

For what it's worth, the Camaro throttle body does not have an  
adjustable TPS.  It just screws on.  You can't move it.

On Saturday, I hooked up my laptop with WinALDL while it was idling  
relatively fast, and it showed about 20 IAC counts, so it would appear  
there isn't an uncontrolled vacuum leak.

Is this a sign of something wrong, something I can tune out with a  
laptop or a scantool, or just the way it's programmed?

I know the idle speed is supposed to increase with the A/C compressor  
clutch engaged, and I see that value in the PROM.  That is not a  
factor in this, though, as it has been so cold I have not needed the  
A/C.  I used it for the first time in a month yesterday, and that was  
for defrost because my windshield fogged up.

Every time I have plugged a laptop into it while it's idling in Park,  
no matter the idle speed, the Park/Neutral flag is set, like it's  
supposed to be.

Any hints will be appreciated.

_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm

From william.lucke at highspeedlink.net  Tue Dec 12 18:32:05 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Tue, 12 Dec 2006 19:32:05 -0500
Subject: [Gmecm] Re: GM circuit numbers
Message-ID: <457F4A05.8030606@highspeedlink.net>

http://auto.ihs.com has the circuit number info in a document called 
"GMW3176".
http://store.ihs.com/specsstore/controller;jsessionid=GtGSbqP-dhjb6crZtJzJyQ**.app12?event=DOCUMENT_DETAILS&docId=KQZBJAAAAAAAAAAA
It's $30 for either hard copy OR electronic copy.

We might have an '86 S-10 manual in our collection. I'll relay that info.


Will


> From: "Steve Ravet" <Steve.Ravet at arm.com>
> Subject: RE: [Gmecm] GM circuit numbers
> 
> That would be useful information.
> 
> The service manual for my '86 S-10 Blazer had that chart in it, but the
> service manual for the '91 Caprice (which donated it's 5.7L TBI motor to
> said Blazer) did not have that chart.  I have not found that chart in
> the '98 full size pickup service manual that I have, although at 8
> billion pages, I might have missed it.  Can you give us a pointer to
> where you found that information?
> 
> --steve 
> 
>> -----Original Message-----
>> From: gmecm-bounces at diy-efi.org 
>> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of William Lucke
>> Sent: Wednesday, December 06, 2006 2:48 PM
>> To: gmecm at diy-efi.org
>> Subject: [Gmecm] GM circuit numbers
>>
>> My dad recently did a project (building full instrumentation 
>> cluster for '90 Suburban) that would have been MUCH easier if 
>> he'd had an index of GM circuit numbers. He's found where to 
>> get that info for $30, but was hoping that there was a free 
>> resource somewhere that had it. Anybody know of such?
>>
>>
>> Will


From Steve.Ravet at arm.com  Tue Dec 12 22:10:14 2006
From: Steve.Ravet at arm.com (Steve Ravet)
Date: Tue, 12 Dec 2006 22:10:14 -0600
Subject: [Gmecm] Idle Speed
Message-ID: <DBB2E4C4173F1749B6C7434140611783017CD7B2@NASDAQ.usa.Arm.com>


> -----Original Message-----
> From: gmecm-bounces at diy-efi.org 
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of jryan at caminofx.org
> Sent: Tuesday, December 12, 2006 8:02 AM
> To: gmecm at diy-efi.org
> Subject: [Gmecm] Idle Speed
> 
> I have a new GM long-block 350 with a throttle body from a 
> Camaro and an Edelbrock 3704 intake manifold.  The ECM is a 
> 1228746, and I am using an ANLU PROM from an '89 9C1 Caprice.
> 
> All in all, the combination runs well, but I am curious about 
> something.
> 
> I went through the minimum idle speed procedure when the 
> weather was relatively cold (in the 40s F daytime).  I got it 
> to idle slow but smooth, around the speed set in the ECM 
> constants table in the PROM, about 560 RPM or so.
> 
> Lately, the weather has warmed up some (to the mid-70s F 
> daytime), and the engine seems to idle faster.  It was idling 
> at around 800 RPM when I shut off the engine after getting 
> home from work yesterday, and when I parked at work this morning.
> 
> Watching the temperature gauge in the dashboard, it seems 
> like, to a point, it idles faster as the engine temperature 
> increases.  I don't see any values in the PROM that would do 
> this, but I may have overlooked something.  Is this normal, 
> or should I look for something wrong?
> 
> For what it's worth, the Camaro throttle body does not have 
> an adjustable TPS.  It just screws on.  You can't move it.
> 
> On Saturday, I hooked up my laptop with WinALDL while it was 
> idling relatively fast, and it showed about 20 IAC counts, so 
> it would appear there isn't an uncontrolled vacuum leak.
> 
> Is this a sign of something wrong, something I can tune out 
> with a laptop or a scantool, or just the way it's programmed?
> 

You should be able to see the "commanded" or "desired" idle, which is
where the ECM is trying to keep the idle.  It changes IAC to get to
there.  What is commanded at the different idles?

There is a lot to idle.  On the gmecm page, look for the "papers by list
members" section and read the idle paper, also possibly the PID paper.

--steve 



From william.lucke at highspeedlink.net  Tue Dec 12 22:24:25 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Tue, 12 Dec 2006 23:24:25 -0500
Subject: [Gmecm] disassembly 101 / writing a commented hack
Message-ID: <457F8079.6010303@highspeedlink.net>

Ok, I downloaded ALDLStuff.zip, opened it up, read the index file and 
figured out that I want A210.DS to work with OBDI Northstar code. 
Looking through A210, I see bit-by-bit definitions for the data that the 
computer spews out the ALDL datastream, but don't see how that tells me 
where in the PROM to look. The first item in the ALDL stream is the PROM 
ID, which is the first byte (two bytes?) of the .bin, so I can search 
for that, but I'm not sure what to do when I get there.

Also, isn't the operating data stored in RAM? How does that bear on 
disassembling the contents of the PROM?



Will


> From: Ryan Hess <rgmecm at yahoo.com>
> Subject: Re: [Gmecm] disassembly 101 / writing a commented hack
> 
> Disappear for 2 days, and I've got 3 pages of new emails from this list.  Cripes!
> 
> Will,
> 
> The P4 is what I'm running.  It's the generic OBDI computer with the 68hc11 variant... 7730, 7727, 9396, 7749 and probably 50 others.  Yours may be a P6, although that may be the OBDI northstar computer.  There's also a P66, which is probably the OBDII computer... maybe.  I'm not entirely sure where the lines are drawn, but it has to do with the processor(s) used.  I wanna say the P6 is a dual hc11 ECM, but again, not sure.  If someone could clarify that, that would be great.
> 
> I use tunercat's disassembler just because it's so simple to use.  I tried using IDA pro, but got nowhere fast.  Maybe with a week long session on how to work it...
> 
> You *need* the ALDL definition, what gets sent in what byte.  With that you can take educated guesses as to what things are and what they do.  For instance, if you know what byte is VSS, you can backtrack into the code for that RAM location, and find everything that looks up the VSS.  Same for EGR, etc, then you can start saying "okay, this block of code has to do with the EGR"...
> 
> You mentioned wanting to use an IAC vs an ISM on yours, but that will require new hardware in addition to the code.  Cadillac is in their own little world as far as their engines and engine management goes.  The 4.9 ISM likely carried over onto the early northstar engine.
> 
> The OBDII ECM was done by Siemens... I think we discussed earlier that they used some nasty compiled code, so disassembly won't help you much there.  Source code would be what you want, and Siemens won't play nice.
> 
> Ryan
> 
> 
> William Lucke <william.lucke at highspeedlink.net> wrote: 
> No I do not have that disassmbler. Is this the correct page to get it: 
> http://dewhisna.home.netcom.com/download.html ?
> 
> I've heard of IDA... I guess I need to get Tunercat's as well and see 
> which one I like.
> 
> I don't know if there is a data definition for the ALDL stream. I would 
> assume so... I don't know about the stock chips, but my modified 
> engine-management-only program refuses to talk to a tech1. It ONLY talks 
> to the Cadillac IPC.
> 
> What's the definition of a P4 ECM? What are the other types? What 
> distinguishes them from each other?
> 
> Thanks
> 
> 
> Will
> 
> 
> 
>> From: davesnothereman at netscape.net
>> Subject: Re: [Gmecm] disassembly 101 / writing a commented hack
>>
>> I use Donald Whisnant's (spelling?) code seeking disassembler.  It's 
>> freeware written to disassemble code from GMECM's.  Tunercat also has 
>> one, but I'm not as familiar with it.  IDA Pro is also good, but not so 
>> free.
>>
>> Is there a data definition file for the norstar ALDL stream?  That 
>> would at least provide the correct order to the ALDL data words if you 
>> can find the ALDL xmit table.
>>
>> Most of the ALDL tables I've looked at begin with the prom id byte 
>> located in the beginning of the calibration.  If you know or can work 
>> out the calibration address then you might be able to make a guess at 
>> the beginning of the ALDL table.
>>
>> You're famaliar with the reset vectors located at the end of Motorola 
>> code... use those to separate code from cal. data.
>>
>> If you're working with a P4 ecm, look for hardware addresses in the 
>> 3XXX range and attempt to use those with known calibrations from other 
>> P4's to locate specific portions of code.  Use pattern matching to 
>> attempt to locate and  identify some common routines such as spark 
>> timing calculation.
>>
>> There's probably people much better at this than I am who can offer 
>> better clues.  But will they?
>>
>> Zaphod
>>
>> -----Original Message-----
>> From: William Lucke 
>> To: gmecm at diy-efi.org
>> Sent: Sun, 14 May 2006 14:53:22 -0400
>> Subject: [Gmecm] disassembly 101 / writing a commented hack
>>
>>    I'd like to get started hacking the OBDI Cadillac Northstar computer 
>> (). I have a couple of different BCC's, as well as a dyno program that 
>> only has engine management turned on.
>>
>>   I'm familiar with assembly and have worked with commercial 68HC11's in 
>> development boards. I'm familiar with the concepts of disassembly and 
>> I'm ready to devote the time necessary to reverse engineer this 
>> program.
>>
>>  What I'm not sure of, however, is where to start.
>>  What's the best disassembler to use on GM chip images?
>>
>>   Is there a listing of the memory locations of the data for the ALDL 
>> stream? Other than starting at the beginning, I'm not entirely sure how 
>> to enter the program and know what's what.
>>
>>
>>  Will


From Dave.Thomas at us.festo.com  Tue Dec 12 22:56:07 2006
From: Dave.Thomas at us.festo.com (Dave Thomas)
Date: Tue, 12 Dec 2006 23:56:07 -0500
Subject: [Gmecm] SER# 1227747 ACSU promID  Idle Problems (Update)
In-Reply-To: <4579FCE1.3000507@vessels-clan.com>
Message-ID: <OFC4E08386.CDDD2C03-ON85257243.00172968-85257243.001B1A0B@MAIL.DE.FESTO.NET>

Just thought I would give you guys an update.  This weekend I tried the
following in order:

1. Capped all vacuum ports with the exception of the MAP sensor. (i.e. PCV,
Vapor Canister, Air pump, EGR, and brake booster.  Unplugged the heater
damper vacuum reservoir plugged my vacuum gauge up.  (no change)
2. Removed EGR checked for carbon, burrs, made a block off plate and
sandwiched in between the EGR and manifold. (Still no change.)
3. Swapped MAP sensor and checked for plugged hose with my 93 Suburban that
I drive everyday. (no change)
4. Plugged the PCV valve hose but left the PCV valve in valve cover,
Plugged air vent into air breather with a vacuum connection.  I had
pressure of 2 psi no vacuum ( I assumed no lifter valley intake leak)
5. Changed ignition coil with 93 Suburban that I drive everyday. (no
change)
6. Changed Ignition module with 93 Suburban that I drive everyday. (no
change)

At this point, I was pretty discouraged so I hooked up my Diacom and
observed what was happening.  The IAC counts at startup went to 65 then
reduced to 35 (Initial motor position no A/C) counts in Park, I then placed
in gear and the counts started decaying and the idle started to reducing
trying to reach the magic 500 rpm.    Usually it would idle at 525 with 0
counts, then I would place the vehicle in park and neutral and I noticed
that the counts would stay at zero.  The engine would idle up ~100 rpm and
settle back down.  Then when I shifted into drive again, the engine would
die but the IAC counts did not increase at all.  So I figured maybe the
computer was still trying to decay the counts to reach 500 rpm but the IAC
had no place to cut off any air flow because it was at 0 already.  So maybe
if you haven't reached the correct idle, I was thinking the car may not
adjust the counts for the extra load.  At this point, I decided to hook all
of the components back up to the TBI (i.e. vacuum lines, air breather, air
pump,  vacuum brake booster) to rule out that maybe the computer was
expecting air from either the PCV valve and air pump.  From here, I kept
decreasing the idle minimum air screw and as I go to around 5 counts at
idle, It was still stalling and cutting off.  Next, I closed the idle screw
further and noticed this time at around 7 counts that the engine would run
a little longer after the shift into gear but it still stalled.  Basically,
I kept reducing the screw until I got to around 20 counts and now it idles
as I shift between park and neutral at 500 rpms.  I have not followed the
service procedure at this point but apparently if your minimum air setting
is to far open the engine runs on anyway with a high idle, but as you get
to the edge of the correct setting but still to far open the computer
cannot control the idle when you load and unload the engine, then comes the
"Zone" and after that my guess is that you will have the problem in the
other direction (i.e. counts to high).  The IAC white paper was invaluable
for understanding what the computer was doing during idle.

I do have one more question though, it seems as though 500 rpm is extremely
low for this vehicle.  Is this an emission setting for 1987?  My 1993
Suburban idles at around 550 rpm.  Also, I heard people say that you should
not see drips of fuel coming from the injectors, but I think I see what
looks as drips in the spray pattern at idle.  Is this normal or not?  I
have a movie I could send to someone if anyone is interested.

Thanks again to everyone for their suggestions,


David Thomas
Food & Packaging SBD Engineer
Festo Corporation
Phone: (704) 527-1427
Fax: (704) 527-7935
email: dave.thomas at us.festo.com






                                                                                                                
         Jay Vessels <jay at vessels-clan.com>                         12/08/2006 07:02 PM                         
                                                                                                                



      Sent by:

      gmecm-bounces at diy-efi.org 12/08/2006 07:01 PM

      Please respond to
gmecm at diy-efi.org

|--+-------------------------------->
|  |                                |
|--+-------------------------------->
  >--------------------------------------------------------------------------------------------------------------------------------------------------|
  |                                                                                                                                                  |
  |                                                                                                                                                  |
  |                                                                                                                                                To|
  |        gmecm at diy-efi.org                                                                                                                         |
  |                                                                                                                                                cc|
  |                                                                                                                                                  |
  |                                                                                                                                           Subject|
  |        Re: [Gmecm] SER# 1227747 ACSU promID  Idle Problems                                                                                       |
  |                                                                                                                                                  |
  |                                                                                                                                                  |
  |                                                                                                                                                  |
  |                                                                                                                                                  |
  |                                                                                                                                                  |
  >--------------------------------------------------------------------------------------------------------------------------------------------------|




Hi there!

> This is after I ground the diagnostic pins on the ALDL connector, wait 10
> seconds for the IAC motor to zero out, remove ground from ALDL and start
> engine.

This may not be the same on all TBI systems, but I don't think that's
the right procedure for your system.  Except for my '84 Cavalier (which
used a rubber plug installed in the TBI) all of the ones I've tuned use
a somewhat different procedure than you describe.

The difference from what you described is that you *don't* remove the
ground from the ALDL port before starting.  Leave it there.  Otherwise,
the ECM will try to control the idle, and you're fighting it with the
throttle stop screw.

Essentially:
1)  Key off, jumper pins A&B on ALDL.
2)  Key on, adjust TPS to proper voltage (0.5V on the ones I've touched,
yours may be different?)
2a)  You may want to unplug the IAC, ensuring the ECM doesn't move the
IAC pintle, but leaving pins Z&B jumpered should do this.
3)  Start engine and let it stabilize.
4)  Adjust idle speed to spec.
5)  Readjust TPS to spec.
6)  Repeat 4 and 5 until both are satisfied.
7)  Shut engine off, remove jumper, and reconnect IAC if unplugged.

Jay Vessels
1982 Chevrolet S-10 Sport, 2.8V6 TBI
1984 Chevrolet S-10 Blazer Sport, 2.8V6 (TBI pending)
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm






From Steve.Ravet at arm.com  Wed Dec 13 09:18:38 2006
From: Steve.Ravet at arm.com (Steve Ravet)
Date: Wed, 13 Dec 2006 09:18:38 -0600
Subject: [Gmecm] SER# 1227747 ACSU promID  Idle Problems (Update)
Message-ID: <DBB2E4C4173F1749B6C7434140611783017CD833@NASDAQ.usa.Arm.com>

 

> -----Original Message-----
> From: gmecm-bounces at diy-efi.org 
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Dave Thomas
> Sent: Tuesday, December 12, 2006 10:56 PM
> To: gmecm at diy-efi.org
> Subject: Re: [Gmecm] SER# 1227747 ACSU promID Idle Problems (Update)
> 
> 
> I do have one more question though, it seems as though 500 
> rpm is extremely low for this vehicle.  Is this an emission 
> setting for 1987?  My 1993 Suburban idles at around 550 rpm.  
> Also, I heard people say that you should not see drips of 
> fuel coming from the injectors, but I think I see what looks 
> as drips in the spray pattern at idle.  Is this normal or 
> not?  I have a movie I could send to someone if anyone is interested.

Dave, I don't think you should see any drops.  I saw drops and it was
leaky O rings around the injectors.  Replaced them and the drops went
away.

glad you got your idle sorted out,

--steve



From jryan at caminofx.org  Wed Dec 13 09:36:13 2006
From: jryan at caminofx.org (jryan at caminofx.org)
Date: Wed, 13 Dec 2006 09:36:13 -0600
Subject: [Gmecm] Idle Speed
Message-ID: <20061213093613.50np73ry80c8w0sk@webmail.caminofx.org>

Well, I did some data logging, and the logs are at home, but I  
remember enough to be useful.

(To refresh: GM long block 350, Crane Cams 2032 roller cam, TBI,  
overdrive, Chevy El Camino, '89 9C1 Caprice 350 ANLU PROM.)

The "target idle speed" in the ECM is about 560 RPM.  The ECM seems to  
want the engine to idle at 875 RPM.  The TPS shows either .41V or .36V  
at idle (why is it different at different times?  I know my foot was  
off the pedal).  The IAC counts are always 40 at idle.

So it looks like the ECM is commanding it, but I don't know why.  By  
the way, the maximum hot idle speed set in the PROM is 900, so I doubt  
that the 875 value is a coincidence.

I am able to get the engine to idle at 560 RPM if I unplug the IAC  
motor.  The ECM is definitely commanding this relatively fast idle.

Another thing I noticed is that I'm running fairly lean.  The BLMs in  
all cells that updated were 137.  I have the 9C1 PROM, but the  
full-size pickup 350 injectors and stock fuel-pressure regulator.

It was suggested to me a while back to bump the fuel pressure to 15  
psi, but at the time, I didn't know I had a leaking injector O-ring  
and it made the car belch black smoke out the pipes.  I am going to  
put the adjustable FPR back in and raise the pressure as soon as I can.

But what I am asking is if the running lean and the fast idle could be  
connected.  I know on a carburetor, a fast idle is often due to  
running very lean, due to a vacuum leak.

What's interesting is that I just drove around the neighborhood, but  
all the cells that updated were right about 137.  It's definitely a  
bit lean.  It also pings ever so slightly on acceleration.

I can supply more hard numbers from the logs when I get home.



From burginsauto at frontiernet.net  Wed Dec 13 16:39:16 2006
From: burginsauto at frontiernet.net (Burgins Auto Service)
Date: Wed, 13 Dec 2006 17:39:16 -0500
Subject: [Gmecm] 4 cyl mod for DIS?
Message-ID: <000001c71f07$86808430$01fea8c0@DFF7PK11>

 

Hi,I'm new to the list. While looking at the archives,I noticed there was
some interest in using 4 cyl modules 

for 8 cyl DIS.

I built a working setup several years ago. Combining the two ref signals
with diodes won't work because the

4 cyl refs have a 66% duty cycle. The waveforms overlap causing a high
signal all the time. A logic AND gate

output is only high when both ref signals from the 4 cyl mods overlap
producing a 8 cyl ref output to to the

ECM @ 33% duty cycle.

To toggle the IC signal to the correct module,I used a JK flipflop with ref
from each 4 cyl mod as J and K inputs.

IC was used as the clock input.

The result is is two outputs to the modules @ 50% duty cycle-don't worry
about dwell cause the 4cyl mods

handle that.

You also need a handfull of descretes for circuit protection(reverse
battery,load dump,ect). Also need a

 transistor controlled from bypass to short out IC to avoid setting a code
42(trust me,it won't run without it)

Build your wheel with enough iron to run the mag pickups.

Due to my unique application,I used a dual hall effect pickup with an inner
and outer wheel phased at 90

degrees and differentiated the signals to the modules. Over time,this proved
to be unreliable.

I have since built a microcontoller based DIS that uses a dual wheel with
wider vanes(one with 4 windows

for ref,and one for sync which allows 58 degrees advance and 28 degrees
retard). The programming 

handles coil coil charge time(dwell),tach output,ref signal to the ECM,coil
sequencing,and limited

diagnostics with trouble code display. I used IGBTs with analog current
control plus the programming

to drive the GM DIS coils.

   Marc

 



From andrewsharyn at yahoo.com  Thu Dec 14 15:52:21 2006
From: andrewsharyn at yahoo.com (Andrew Gibson)
Date: Thu, 14 Dec 2006 13:52:21 -0800 (PST)
Subject: [Gmecm] Re: 4 cyl mod for DIS?
Message-ID: <220764.60029.qm@web60823.mail.yahoo.com>

Somewhere out there in the great blue internet I found a page with instructions on how to use dual GM 4cyl DIS to run ignition on a Cessna 4cyl airplane. It used double everything with reference holes drilled in the harmonic dampner. His application had the sensors 32 degrees apart to allow startup and cruise ignition timing and a toggle switch to switch in between.
   
  I think you could do the same thing on an 8cyl and have the pickup sensors 90 degrees apart. Two ecms would be required to make the est work. As the 4cyl dis uses a 7 slot pickup with two of the slots 10 degrees apart, tricking the module for base timing will be difficult. However I found out the module translates the 7 pulse per rotation signal into a 2 pulse per rotation signal for the ecm to better conrol timing and fuel. (I should know, my truck is using a distributor and est module with a 7748 ecm and throttle body off a 2.5L DIS motor)

 
---------------------------------
Want to start your own business? Learn how on Yahoo! Small Business.

From BNRVL at aol.com  Fri Dec 15 08:53:33 2006
From: BNRVL at aol.com (BNRVL at aol.com)
Date: Fri, 15 Dec 2006 09:53:33 EST
Subject: [Gmecm] Re: 4 cyl mod for DIS?
Message-ID: <cc6.5daafa0.32b410ed@aol.com>


   hello Andrews , what is your intention for the Airplane useage  ??

 Be sure to clear with FAA, STC , AD  and your insurance carrier , so you 
wont be left out in the cold , should an incident occur with the Cessna .

 I had two 1975 Bellanca Citabria's a few years back and instructors totaled 
both of them .

 Glad we had good insurance coverage .

 Thanks 

 Merry Christmas 

 Bob Norville


From william.lucke at highspeedlink.net  Fri Dec 15 12:50:01 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Fri, 15 Dec 2006 13:50:01 -0500
Subject: [Gmecm] Re: 4 cyl mod for DIS?
Message-ID: <4582EE59.2030107@highspeedlink.net>

The double notch is just for synchronizing to TDC #1, so the 7 tooth 
wheel is really a 6 tooth wheel. Of these 6 pulses, a 6 cylinder DIS 
passes every other pulse to the ECM and a 4 cylinder DIS passes every 
third pulse.
With that logic, it would take a 12 tooth wheel to work an 8 cylinder 
DIS... the 8 cylinder module would pass every third, the 6 cylinder 
every fourth and the 4 cylinder every 6th.



Will




> From: Andrew Gibson <andrewsharyn at yahoo.com>
> Subject: [Gmecm] Re: 4 cyl mod for DIS?
> 
> Somewhere out there in the great blue internet I found a page with instructions on how to use dual GM 4cyl DIS to run ignition on a Cessna 4cyl airplane. It used double everything with reference holes drilled in the harmonic dampner. His application had the sensors 32 degrees apart to allow startup and cruise ignition timing and a toggle switch to switch in between.
>    
>   I think you could do the same thing on an 8cyl and have the pickup sensors 90 degrees apart. Two ecms would be required to make the est work. As the 4cyl dis uses a 7 slot pickup with two of the slots 10 degrees apart, tricking the module for base timing will be difficult. However I found out the module translates the 7 pulse per rotation signal into a 2 pulse per rotation signal for the ecm to better conrol timing and fuel. (I should know, my truck is using a distributor and est module with a 7748 ecm and throttle body off a 2.5L DIS motor)



From andrewsharyn at yahoo.com  Fri Dec 15 12:58:25 2006
From: andrewsharyn at yahoo.com (Andrew Gibson)
Date: Fri, 15 Dec 2006 10:58:25 -0800 (PST)
Subject: [Gmecm] Re: 4 cyl mod for DIS?
Message-ID: <482883.12548.qm@web60817.mail.yahoo.com>

I actually don't have an airpalne. I found the site while doing a search for GM DIS. I found it very helpful in the information department. If I can find it again I will post the site name so you can look at it.
 __________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 

From andrewsharyn at yahoo.com  Sat Dec 16 22:15:47 2006
From: andrewsharyn at yahoo.com (Andrew Gibson)
Date: Sat, 16 Dec 2006 20:15:47 -0800 (PST)
Subject: [Gmecm] Re: 4 cyl mod for DIS? 
Message-ID: <710375.32252.qm@web60814.mail.yahoo.com>

>The double notch is just for synchronizing to TDC #1, so the 7 tooth 
>wheel is really a 6 tooth wheel. Of these 6 pulses, a 6 cylinder DIS 
>passes every other pulse to the ECM and a 4 cylinder DIS passes every 
>third pulse.
>With that logic, it would take a 12 tooth wheel to work an 8 cylinder 
>DIS... the 8 cylinder module would pass every third, the 6 cylinder 
>every fourth and the 4 cylinder every 6th.

  I agree with that. But the DIS module still needs to know which coil to fire and still translates the signal for the ecm. And interestingly enough the late model sequential multiport injection GM engines all use a 24x signal. It's actually a 8 tooth wheel with the other 16 pulses calculated by either the ecm or module depending on the year and engine.
   
  I feel a huge GM DIS thoery discussion coming on.

 __________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 

From info at jenkinseng.com  Sun Dec 17 15:17:35 2006
From: info at jenkinseng.com (Peter Jenkins)
Date: Mon, 18 Dec 2006 08:17:35 +1100
Subject: [Gmecm] re 4 cyl mod for dis
Message-ID: <001501c72220$cd2e2600$6501a8c0@PETER>

I have actually fitted the 4cyl dis on a Toyota engine and  I drilled the holes in the flywheel my understanding was that the six holes were located with one at tdc and a seventh at 10 btdc for the module mode: if you wanted to run two modules and ecu's then you could drill another set of holes closer to the centre of the flywheel and have another crank sensor .
By the way I am running my jag v12 using two 6 cyl dis packs and two 1227808 ecu's and have had this discussion before on this sight and the forum .
With the 8cyl why not just use the ecu and dis pack already made to do the job ?
the 12 cyl does not have the hard ware ! if I use one ecu and two sensors you half the rpm capacity by doubling the rpm seen by the ecu, I have a test bench set up to try it all out.if someone can come up with a component to double the est output and split it two ways then the problem is solved .then can use two modules two crank sensors to time the dis packs and est then cuts in and times both dis packs by only using one crank sensor .have put a circuit diagram at this link
http://gmecm.mine.nu/viewtopic.php?t=44
http://www.diy-efi.org/twiki/bin/viewfile.pl/Gmecm/Running2DisPacksOff1Ecu?rev=1;filename=ECU_wiring.jpg
> Peter Jenkins
> 10336 Murray River Rd
Pine Mountain Vic. 3709
> Australia.

> PH 0425 705764
> Email. info at jenkinseng.com 
> web. www.jenkinseng.com                                 DISCLAIMER
>  * This email and any attachment may contain confidential information.
>     If you are not the intended recipient you are not authorised to copy
>     or disclose all or any part of it without the prior written consent
>     of Jenkins Engineering.
>  * Opinions expressed in this email and any attachment are those of the
>    sender and not necessarily the opinions of Jenkins Engineering.
>  * Please scan this email and any attachment for viruses. Jenkins 
> Engineering does
>    not accept responsibility for problems caused by viruses, whether 
> it is Jenkins Engineering's fault or not!!!



From captain_krill at yahoo.com  Mon Dec 18 14:00:37 2006
From: captain_krill at yahoo.com (Cowen)
Date: Mon, 18 Dec 2006 12:00:37 -0800 (PST)
Subject: [Gmecm] V8 DIS
Message-ID: <20061218200037.89516.qmail@web34313.mail.mud.yahoo.com>


> With the 8cyl why not just use the ecu and dis pack
> already made to do the job?

Like the Corvettes and Camaros???  I can't figure out
why a Cavalier gets DIS but a Corvette gets OptiSpark.
 Anyone know why GM didn't use DIS in more V8
applications?   

**********************END TRANSMISSION**********************

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 


From dunvegan at sbcglobal.net  Mon Dec 18 14:58:17 2006
From: dunvegan at sbcglobal.net (Rick McLeod)
Date: Mon, 18 Dec 2006 12:58:17 -0800 (PST)
Subject: [Gmecm] Idle Speed
Message-ID: <20061218205817.21050.qmail@web80504.mail.yahoo.com>

Just curious, was re-reading this thread and had a question:

are you running EGR, and if so is it stuck, these 'related' symptoms of ping and idle have been caused by bad EGR control before.

just a thought, fwiw


----- Original Message ----
From: "jryan at caminofx.org" <jryan at caminofx.org>
To: gmecm at diy-efi.org
Sent: Wednesday, December 13, 2006 9:36:13 AM
Subject: [Gmecm] Idle Speed


Well, I did some data logging, and the logs are at home, but I  
remember enough to be useful.

(To refresh: GM long block 350, Crane Cams 2032 roller cam, TBI,  
overdrive, Chevy El Camino, '89 9C1 Caprice 350 ANLU PROM.)

The "target idle speed" in the ECM is about 560 RPM.  The ECM seems to  
want the engine to idle at 875 RPM.  The TPS shows either .41V or .36V  
at idle (why is it different at different times?  I know my foot was  
off the pedal).  The IAC counts are always 40 at idle.

So it looks like the ECM is commanding it, but I don't know why.  By  
the way, the maximum hot idle speed set in the PROM is 900, so I doubt  
that the 875 value is a coincidence.

I am able to get the engine to idle at 560 RPM if I unplug the IAC  
motor.  The ECM is definitely commanding this relatively fast idle.

Another thing I noticed is that I'm running fairly lean.  The BLMs in  
all cells that updated were 137.  I have the 9C1 PROM, but the  
full-size pickup 350 injectors and stock fuel-pressure regulator.

It was suggested to me a while back to bump the fuel pressure to 15  
psi, but at the time, I didn't know I had a leaking injector O-ring  
and it made the car belch black smoke out the pipes.  I am going to  
put the adjustable FPR back in and raise the pressure as soon as I can.

But what I am asking is if the running lean and the fast idle could be  
connected.  I know on a carburetor, a fast idle is often due to  
running very lean, due to a vacuum leak.

What's interesting is that I just drove around the neighborhood, but  
all the cells that updated were right about 137.  It's definitely a  
bit lean.  It also pings ever so slightly on acceleration.

I can supply more hard numbers from the logs when I get home.

_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm

From tim.paxton at ge.com  Tue Dec 19 08:06:07 2006
From: tim.paxton at ge.com (Paxton, Tim (GE Indust, ConsInd))
Date: Tue, 19 Dec 2006 09:06:07 -0500
Subject: [Gmecm] S-10 ECM 1227165, Broadcast code ASWY
Message-ID: <A69124856290784B9AE28180362940F10A10F8@LOUMLVEM04.e2k.ad.ge.com>

Hi,

I am looking for some info on an ECM that came out of a 90 S-10 pickup. My dad and I want to use it to run a VW bug motor. I am currently using Tunerpro RT to tune my 94 full size Blazer so it would be nice if I could find the .bin, .xdf, and .ads file for the S-10 computer. This is the info I have.

ECM Part number
1227165
Broadcast Code
ASWY
Program ID Byte ( per tunercats web site )
$83A
Data Stream
A99

Thanks
Tim







From dunvegan at sbcglobal.net  Tue Dec 19 10:21:16 2006
From: dunvegan at sbcglobal.net (Rick McLeod)
Date: Tue, 19 Dec 2006 08:21:16 -0800 (PST)
Subject: [Gmecm] S-10 ECM 1227165, Broadcast code ASWY
Message-ID: <20061219162116.64523.qmail@web80512.mail.yahoo.com>

if TC has the mask (don't know, didn't look) for the $83A, why not acquire it and browse the tables, etc, as it will expose a lot about the capability. I'm not familiar w/ the S10 implementations, but have considerable time w/ that ECM on 8cyl TPI's in Camaro/Corvette L98's. If you're going to go to port injection w/ MAF, it should be quite capable, but I suspect on a buggy you'd be limited to TBI and I suspect there are other ECM's more suitable to that, like the '7747 or other variants.


----- Original Message ----
From: "Paxton, Tim (GE Indust, ConsInd)" <tim.paxton at ge.com>
To: gmecm at diy-efi.org
Sent: Tuesday, December 19, 2006 8:06:07 AM
Subject: [Gmecm] S-10 ECM 1227165, Broadcast code ASWY


Hi,

I am looking for some info on an ECM that came out of a 90 S-10 pickup. My dad and I want to use it to run a VW bug motor. I am currently using Tunerpro RT to tune my 94 full size Blazer so it would be nice if I could find the .bin, .xdf, and .ads file for the S-10 computer. This is the info I have.

ECM Part number
1227165
Broadcast Code
ASWY
Program ID Byte ( per tunercats web site )
$83A
Data Stream
A99

Thanks
Tim

From lwester at lincsat.com  Tue Dec 19 14:09:35 2006
From: lwester at lincsat.com (Programmer)
Date: Tue, 19 Dec 2006 13:09:35 -0700
Subject: [Gmecm] S-10 ECM 1227165, Broadcast code ASWY
References: <20061219162116.64523.qmail@web80512.mail.yahoo.com>
Message-ID: <000e01c723a9$a2551a80$0200a8c0@WESTER2>

The 2.5L with '165 ECM was in fact a TBI app...remember when everyone said 
you couldn't run 8 PFI injectors with a TBI ECM ?

LW

----- Original Message ----- 
From: "Rick McLeod" <dunvegan at sbcglobal.net>
To: <gmecm at diy-efi.org>
Sent: Tuesday, December 19, 2006 9:21 AM
Subject: Re: [Gmecm] S-10 ECM 1227165, Broadcast code ASWY


> if TC has the mask (don't know, didn't look) for the $83A, why not acquire 
> it and browse the tables, etc, as it will expose a lot about the 
> capability. I'm not familiar w/ the S10 implementations, but have 
> considerable time w/ that ECM on 8cyl TPI's in Camaro/Corvette L98's. If 
> you're going to go to port injection w/ MAF, it should be quite capable, 
> but I suspect on a buggy you'd be limited to TBI and I suspect there are 
> other ECM's more suitable to that, like the '7747 or other variants.
>
>
> ----- Original Message ----
> From: "Paxton, Tim (GE Indust, ConsInd)" <tim.paxton at ge.com>
> To: gmecm at diy-efi.org
> Sent: Tuesday, December 19, 2006 8:06:07 AM
> Subject: [Gmecm] S-10 ECM 1227165, Broadcast code ASWY
>
>
> Hi,
>
> I am looking for some info on an ECM that came out of a 90 S-10 pickup. My 
> dad and I want to use it to run a VW bug motor. I am currently using 
> Tunerpro RT to tune my 94 full size Blazer so it would be nice if I could 
> find the .bin, .xdf, and .ads file for the S-10 computer. This is the info 
> I have.
>
> ECM Part number
> 1227165
> Broadcast Code
> ASWY
> Program ID Byte ( per tunercats web site )
> $83A
> Data Stream
> A99
>
> Thanks
> Tim
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm 



From tim.paxton at ge.com  Wed Dec 20 12:23:14 2006
From: tim.paxton at ge.com (Paxton, Tim (GE Indust, ConsInd))
Date: Wed, 20 Dec 2006 13:23:14 -0500
Subject: [Gmecm] Re: S-10 ECM 1227165, Broadcast code ASWY (Programmer)
In-Reply-To: <200612201800.kBKI0t3u001961@ext-ch1gw-2.online-age.net>
Message-ID: <A69124856290784B9AE28180362940F10A10FB@LOUMLVEM04.e2k.ad.ge.com>



Tim Paxton
GE Consumer Industrial
AP-2 Electronics Lab 
Scheduler

Desk 502-452-5414
Lab 502-452-3918
Fax 502-452-0759
tim.paxton at ge.com

Appliance Park AP-2C-56
Louisville, KY 40225 
General Electric Company




-----Original Message-----
From: gmecm-bounces at diy-efi.org [mailto:gmecm-bounces at diy-efi.org]On
Behalf Of gmecm-request at diy-efi.org
Sent: Wednesday, December 20, 2006 1:01 PM
To: gmecm at diy-efi.org
Subject: Gmecm Digest, Vol 22, Issue 23


Thanks guys.

With some more surching I found what I needed to run everthing from TunerPro. The files are on the moates file page.




Send Gmecm mailing list submissions to
	gmecm at diy-efi.org

To subscribe or unsubscribe via the World Wide Web, visit
	http://lists.diy-efi.org/mailman/listinfo/gmecm
or, via email, send a message with subject or body 'help' to
	gmecm-request at diy-efi.org

You can reach the person managing the list at
	gmecm-owner at diy-efi.org

When replying, please edit your Subject line so it is more specific
than "Re: Contents of Gmecm digest..."


Today's Topics:

   1. Re: S-10 ECM 1227165, Broadcast code ASWY (Programmer)


----------------------------------------------------------------------

Message: 1
Date: Tue, 19 Dec 2006 13:09:35 -0700
From: "Programmer" <lwester at lincsat.com>
Subject: Re: [Gmecm] S-10 ECM 1227165, Broadcast code ASWY
To: <gmecm at diy-efi.org>
Message-ID: <000e01c723a9$a2551a80$0200a8c0 at WESTER2>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
	reply-type=original

The 2.5L with '165 ECM was in fact a TBI app...remember when everyone said 
you couldn't run 8 PFI injectors with a TBI ECM ?

LW

----- Original Message ----- 
From: "Rick McLeod" <dunvegan at sbcglobal.net>
To: <gmecm at diy-efi.org>
Sent: Tuesday, December 19, 2006 9:21 AM
Subject: Re: [Gmecm] S-10 ECM 1227165, Broadcast code ASWY


> if TC has the mask (don't know, didn't look) for the $83A, why not acquire 
> it and browse the tables, etc, as it will expose a lot about the 
> capability. I'm not familiar w/ the S10 implementations, but have 
> considerable time w/ that ECM on 8cyl TPI's in Camaro/Corvette L98's. If 
> you're going to go to port injection w/ MAF, it should be quite capable, 
> but I suspect on a buggy you'd be limited to TBI and I suspect there are 
> other ECM's more suitable to that, like the '7747 or other variants.
>
>
> ----- Original Message ----
> From: "Paxton, Tim (GE Indust, ConsInd)" <tim.paxton at ge.com>
> To: gmecm at diy-efi.org
> Sent: Tuesday, December 19, 2006 8:06:07 AM
> Subject: [Gmecm] S-10 ECM 1227165, Broadcast code ASWY
>
>
> Hi,
>
> I am looking for some info on an ECM that came out of a 90 S-10 pickup. My 
> dad and I want to use it to run a VW bug motor. I am currently using 
> Tunerpro RT to tune my 94 full size Blazer so it would be nice if I could 
> find the .bin, .xdf, and .ads file for the S-10 computer. This is the info 
> I have.
>
> ECM Part number
> 1227165
> Broadcast Code
> ASWY
> Program ID Byte ( per tunercats web site )
> $83A
> Data Stream
> A99
>
> Thanks
> Tim
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm 



------------------------------

_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
http://lists.diy-efi.org/mailman/listinfo/gmecm


End of Gmecm Digest, Vol 22, Issue 23
*************************************


From craig.moates at cox.net  Thu Dec 21 00:09:24 2006
From: craig.moates at cox.net (Craig Moates)
Date: Thu, 21 Dec 2006 00:09:24 -0600
Subject: [Gmecm] Any USB developers out there?
References: <DBB2E4C4173F1749B6C743414061178301700E3E@NASDAQ.usa.Arm.com>
Message-ID: <002001c724c6$9079bb90$b800a8c0@antec>

Steve,

I've put together an 'alternate' layout for USB-to-VPW. Feel free to take a look. I have yet to stitch together all of the 
connections, but given about an hour or so, it can be cleaned up and made to be pretty tight. Check the readme.txt for comments.

I just did it from scratch, based on the datasheets and takeoffs from what I've done before. But it could be made to be pretty tight 
and workable, and very low cost as well. It doesn't have integrated USB in the micro, but on the other hand, it would be able to use 
standard COM port protocols. You could set it up with a bootloader as well to make it field updateable.

Y'all are welcome to play however you like. I'm going to beat on it some more and get all the connectivity together. Might even hit 
on the firmware if I can find a spare day or two. Ha! Feel free to put it in as part of the Wiki for the GMECM stuff. It's a work in 
progress to be sure, but I figured I'd share what I had thus far.

www.moates.net/projects/class2/

Best regards,
Craig Moates


----- Original Message ----- 
From: "Steve Ravet" <Steve.Ravet at arm.com>
To: <gmecm at diy-efi.org>
Sent: Sunday, November 19, 2006 11:41 PM
Subject: RE: [Gmecm] Any USB developers out there?




> -----Original Message-----
> From: gmecm-bounces at diy-efi.org
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Craig Moates
> Sent: Thursday, November 09, 2006 11:51 AM
> To: gmecm at diy-efi.org
> Subject: Re: [Gmecm] Any USB developers out there?
>
> Steve,
>
> Definitely check the crystal and capacitor areas. Those are
> ceramics you are using for the 18pF set? Check that it's set
> up for 18pf on the xtal desired capacitance?

The crystal is 20 MHz 18pf according to the digikey datasheet.  They're
ceramic caps.

I don't know what the problem with the crystal circuit is, but I removed
it and used a 4 MHz OSC instead, changing the firmware accordingly, and
now it works.  I tried with and without the load resistor (on the
crystal) but no change.  The demo board has an external load resistor
but the data sheet shows a resistor internal to the part.

I decided that I want USB power after all so I can reflash the PIC
without external power.  You mentioned the circuit you use but I can't
find the note now.  What is it?

Craig, what do you use for schematic capture and PCB layout?

Maybe there'll be a USB <-> VPW project working by Christmas now...

thanks for the suggestions everyone,

--steve

_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm



From b.shaw at comcast.net  Thu Dec 21 07:32:01 2006
From: b.shaw at comcast.net (Bill Shaw)
Date: Thu, 21 Dec 2006 08:32:01 -0500
Subject: [Gmecm] Any USB developers out there?
In-Reply-To: <002001c724c6$9079bb90$b800a8c0@antec>
References: <DBB2E4C4173F1749B6C743414061178301700E3E@NASDAQ.usa.Arm.com>
	<002001c724c6$9079bb90$b800a8c0@antec>
Message-ID: <458A8CD1.8050504@comcast.net>

Hi Craig,

What schematic capture are you using for this?  The first problem I see 
is the 68hc58,  Freescale says it's obsolete and not recommended for new 
designs.

Best,

Bill

Craig Moates wrote:
> Steve,
>
> I've put together an 'alternate' layout for USB-to-VPW. Feel free to 
> take a look. I have yet to stitch together all of the connections, but 
> given about an hour or so, it can be cleaned up and made to be pretty 
> tight. Check the readme.txt for comments.
>
> I just did it from scratch, based on the datasheets and takeoffs from 
> what I've done before. But it could be made to be pretty tight and 
> workable, and very low cost as well. It doesn't have integrated USB in 
> the micro, but on the other hand, it would be able to use standard COM 
> port protocols. You could set it up with a bootloader as well to make 
> it field updateable.
>
> Y'all are welcome to play however you like. I'm going to beat on it 
> some more and get all the connectivity together. Might even hit on the 
> firmware if I can find a spare day or two. Ha! Feel free to put it in 
> as part of the Wiki for the GMECM stuff. It's a work in progress to be 
> sure, but I figured I'd share what I had thus far.
>
> www.moates.net/projects/class2/
>
> Best regards,
> Craig Moates
>
>
> ----- Original Message ----- From: "Steve Ravet" <Steve.Ravet at arm.com>
> To: <gmecm at diy-efi.org>
> Sent: Sunday, November 19, 2006 11:41 PM
> Subject: RE: [Gmecm] Any USB developers out there?
>
>
>
>
>> -----Original Message-----
>> From: gmecm-bounces at diy-efi.org
>> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Craig Moates
>> Sent: Thursday, November 09, 2006 11:51 AM
>> To: gmecm at diy-efi.org
>> Subject: Re: [Gmecm] Any USB developers out there?
>>
>> Steve,
>>
>> Definitely check the crystal and capacitor areas. Those are
>> ceramics you are using for the 18pF set? Check that it's set
>> up for 18pf on the xtal desired capacitance?
>
> The crystal is 20 MHz 18pf according to the digikey datasheet.  They're
> ceramic caps.
>
> I don't know what the problem with the crystal circuit is, but I removed
> it and used a 4 MHz OSC instead, changing the firmware accordingly, and
> now it works.  I tried with and without the load resistor (on the
> crystal) but no change.  The demo board has an external load resistor
> but the data sheet shows a resistor internal to the part.
>
> I decided that I want USB power after all so I can reflash the PIC
> without external power.  You mentioned the circuit you use but I can't
> find the note now.  What is it?
>
> Craig, what do you use for schematic capture and PCB layout?
>
> Maybe there'll be a USB <-> VPW project working by Christmas now...
>
> thanks for the suggestions everyone,
>
> --steve
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>



From craig.moates at cox.net  Thu Dec 21 09:07:02 2006
From: craig.moates at cox.net (Craig Moates)
Date: Thu, 21 Dec 2006 09:07:02 -0600
Subject: [Gmecm] Any USB developers out there?
References: <DBB2E4C4173F1749B6C743414061178301700E3E@NASDAQ.usa.Arm.com><002001c724c6$9079bb90$b800a8c0@antec>
	<458A8CD1.8050504@comcast.net>
Message-ID: <00ab01c72511$abd36c60$b800a8c0@antec>

Bill,

This is in Cadsoft Eagle 4.16 (www.cadsoft.de), it should fit in the 'Free' version but I haven't tried it that way.

Agreed on the 68HC58, it is obsolete. But I've got a few hundred laying around from another project so figured I'd try and make use 
of it. Plus you can still get it from sources like www.newark.com I think they have 700+ in stock at sub $4 each. Eventually it'll 
dry up in terms of supply, and the design will need to be updated.

Are there any updated chipsets which would handle all the VPW timing and encoding including 4x? I've seen the line level stuff like 
the MC33990, but you have to do all the pulewidth management at the micro side. I think that would be a great way to go, but would 
put more burden on the firmware development side. Maybe eventually, but for a quick-hit, the 68HC58 should cut it. Open to other 
ideas though.

Best regards,
Craig Moates


----- Original Message ----- 
From: "Bill Shaw" <b.shaw at comcast.net>
To: <gmecm at diy-efi.org>
Sent: Thursday, December 21, 2006 7:32 AM
Subject: Re: [Gmecm] Any USB developers out there?


> Hi Craig,
>
> What schematic capture are you using for this?  The first problem I see is the 68hc58,  Freescale says it's obsolete and not 
> recommended for new designs.
>
> Best,
>
> Bill
>
> Craig Moates wrote:
>> Steve,
>>
>> I've put together an 'alternate' layout for USB-to-VPW. Feel free to take a look. I have yet to stitch together all of the 
>> connections, but given about an hour or so, it can be cleaned up and made to be pretty tight. Check the readme.txt for comments.
>>
>> I just did it from scratch, based on the datasheets and takeoffs from what I've done before. But it could be made to be pretty 
>> tight and workable, and very low cost as well. It doesn't have integrated USB in the micro, but on the other hand, it would be 
>> able to use standard COM port protocols. You could set it up with a bootloader as well to make it field updateable.
>>
>> Y'all are welcome to play however you like. I'm going to beat on it some more and get all the connectivity together. Might even 
>> hit on the firmware if I can find a spare day or two. Ha! Feel free to put it in as part of the Wiki for the GMECM stuff. It's a 
>> work in progress to be sure, but I figured I'd share what I had thus far.
>>
>> www.moates.net/projects/class2/
>>
>> Best regards,
>> Craig Moates
>>
>>
>> ----- Original Message ----- From: "Steve Ravet" <Steve.Ravet at arm.com>
>> To: <gmecm at diy-efi.org>
>> Sent: Sunday, November 19, 2006 11:41 PM
>> Subject: RE: [Gmecm] Any USB developers out there?
>>
>>
>>
>>
>>> -----Original Message-----
>>> From: gmecm-bounces at diy-efi.org
>>> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Craig Moates
>>> Sent: Thursday, November 09, 2006 11:51 AM
>>> To: gmecm at diy-efi.org
>>> Subject: Re: [Gmecm] Any USB developers out there?
>>>
>>> Steve,
>>>
>>> Definitely check the crystal and capacitor areas. Those are
>>> ceramics you are using for the 18pF set? Check that it's set
>>> up for 18pf on the xtal desired capacitance?
>>
>> The crystal is 20 MHz 18pf according to the digikey datasheet.  They're
>> ceramic caps.
>>
>> I don't know what the problem with the crystal circuit is, but I removed
>> it and used a 4 MHz OSC instead, changing the firmware accordingly, and
>> now it works.  I tried with and without the load resistor (on the
>> crystal) but no change.  The demo board has an external load resistor
>> but the data sheet shows a resistor internal to the part.
>>
>> I decided that I want USB power after all so I can reflash the PIC
>> without external power.  You mentioned the circuit you use but I can't
>> find the note now.  What is it?
>>
>> Craig, what do you use for schematic capture and PCB layout?
>>
>> Maybe there'll be a USB <-> VPW project working by Christmas now...
>>
>> thanks for the suggestions everyone,
>>
>> --steve
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 



From b.shaw at comcast.net  Thu Dec 21 09:30:38 2006
From: b.shaw at comcast.net (Bill Shaw)
Date: Thu, 21 Dec 2006 10:30:38 -0500
Subject: [Gmecm] Any USB developers out there?
In-Reply-To: <00ab01c72511$abd36c60$b800a8c0@antec>
References: <DBB2E4C4173F1749B6C743414061178301700E3E@NASDAQ.usa.Arm.com><002001c724c6$9079bb90$b800a8c0@antec>	<458A8CD1.8050504@comcast.net>
	<00ab01c72511$abd36c60$b800a8c0@antec>
Message-ID: <458AA89E.30000@comcast.net>

Motorola has discontinued almost everything containing a BDLC,  says 
J1850 is loosing popularity.  The only thing they still have in the 
product line is a couple of HC12 variants with BDLC.  GM is going all 
CAN as of 2008.  Bit-banging looks like the only real alternative 
besides ELM for new devices,  and ELM is just a bit banging 
implementation itself.

Bill

Craig Moates wrote:
> Bill,
>
> This is in Cadsoft Eagle 4.16 (www.cadsoft.de), it should fit in the 
> 'Free' version but I haven't tried it that way.
>
> Agreed on the 68HC58, it is obsolete. But I've got a few hundred 
> laying around from another project so figured I'd try and make use of 
> it. Plus you can still get it from sources like www.newark.com I think 
> they have 700+ in stock at sub $4 each. Eventually it'll dry up in 
> terms of supply, and the design will need to be updated.
>
> Are there any updated chipsets which would handle all the VPW timing 
> and encoding including 4x? I've seen the line level stuff like the 
> MC33990, but you have to do all the pulewidth management at the micro 
> side. I think that would be a great way to go, but would put more 
> burden on the firmware development side. Maybe eventually, but for a 
> quick-hit, the 68HC58 should cut it. Open to other ideas though.
>
> Best regards,
> Craig Moates
>
>
> ----- Original Message ----- From: "Bill Shaw" <b.shaw at comcast.net>
> To: <gmecm at diy-efi.org>
> Sent: Thursday, December 21, 2006 7:32 AM
> Subject: Re: [Gmecm] Any USB developers out there?
>
>
>> Hi Craig,
>>
>> What schematic capture are you using for this?  The first problem I 
>> see is the 68hc58,  Freescale says it's obsolete and not recommended 
>> for new designs.
>>
>> Best,
>>
>> Bill
>>
>> Craig Moates wrote:
>>> Steve,
>>>
>>> I've put together an 'alternate' layout for USB-to-VPW. Feel free to 
>>> take a look. I have yet to stitch together all of the connections, 
>>> but given about an hour or so, it can be cleaned up and made to be 
>>> pretty tight. Check the readme.txt for comments.
>>>
>>> I just did it from scratch, based on the datasheets and takeoffs 
>>> from what I've done before. But it could be made to be pretty tight 
>>> and workable, and very low cost as well. It doesn't have integrated 
>>> USB in the micro, but on the other hand, it would be able to use 
>>> standard COM port protocols. You could set it up with a bootloader 
>>> as well to make it field updateable.
>>>
>>> Y'all are welcome to play however you like. I'm going to beat on it 
>>> some more and get all the connectivity together. Might even hit on 
>>> the firmware if I can find a spare day or two. Ha! Feel free to put 
>>> it in as part of the Wiki for the GMECM stuff. It's a work in 
>>> progress to be sure, but I figured I'd share what I had thus far.
>>>
>>> www.moates.net/projects/class2/
>>>
>>> Best regards,
>>> Craig Moates
>>>
>>>
>>> ----- Original Message ----- From: "Steve Ravet" <Steve.Ravet at arm.com>
>>> To: <gmecm at diy-efi.org>
>>> Sent: Sunday, November 19, 2006 11:41 PM
>>> Subject: RE: [Gmecm] Any USB developers out there?
>>>
>>>
>>>
>>>
>>>> -----Original Message-----
>>>> From: gmecm-bounces at diy-efi.org
>>>> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Craig Moates
>>>> Sent: Thursday, November 09, 2006 11:51 AM
>>>> To: gmecm at diy-efi.org
>>>> Subject: Re: [Gmecm] Any USB developers out there?
>>>>
>>>> Steve,
>>>>
>>>> Definitely check the crystal and capacitor areas. Those are
>>>> ceramics you are using for the 18pF set? Check that it's set
>>>> up for 18pf on the xtal desired capacitance?
>>>
>>> The crystal is 20 MHz 18pf according to the digikey datasheet.  They're
>>> ceramic caps.
>>>
>>> I don't know what the problem with the crystal circuit is, but I 
>>> removed
>>> it and used a 4 MHz OSC instead, changing the firmware accordingly, and
>>> now it works.  I tried with and without the load resistor (on the
>>> crystal) but no change.  The demo board has an external load resistor
>>> but the data sheet shows a resistor internal to the part.
>>>
>>> I decided that I want USB power after all so I can reflash the PIC
>>> without external power.  You mentioned the circuit you use but I can't
>>> find the note now.  What is it?
>>>
>>> Craig, what do you use for schematic capture and PCB layout?
>>>
>>> Maybe there'll be a USB <-> VPW project working by Christmas now...
>>>
>>> thanks for the suggestions everyone,
>>>
>>> --steve



From jshroff at hotmail.com  Thu Dec 21 11:20:15 2006
From: jshroff at hotmail.com (Jay Shroff)
Date: Thu, 21 Dec 2006 17:20:15 +0000
Subject: [Gmecm] Any USB developers out there?
Message-ID: <BAY124-W44C325175B2F7CD2B45D56A3CE0@phx.gbl>

There seems to be a competitor to ELM who posted on this list
 
www.obdpros.com
 
Maybe they are willing to provide the micro's at a much lower cost than ELM. I have been playing around with one of those devices and it seems to be able to keep up with a pretty busy J1850 bus on a 1996 Chevy Avalanche.
Jay



> Date: Thu, 21 Dec 2006 10:30:38 -0500> From: b.shaw at comcast.net> To: gmecm at diy-efi.org> Subject: Re: [Gmecm] Any USB developers out there?> > Motorola has discontinued almost everything containing a BDLC, says > J1850 is loosing popularity. The only thing they still have in the > product line is a couple of HC12 variants with BDLC. GM is going all > CAN as of 2008. Bit-banging looks like the only real alternative > besides ELM for new devices, and ELM is just a bit banging > implementation itself.> > Bill> > Craig Moates wrote:> > Bill,> >> > This is in Cadsoft Eagle 4.16 (www.cadsoft.de), it should fit in the > > 'Free' version but I haven't tried it that way.> >> > Agreed on the 68HC58, it is obsolete. But I've got a few hundred > > laying around from another project so figured I'd try and make use of > > it. Plus you can still get it from sources like www.newark.com I think > > they have 700+ in stock at sub $4 each. Eventually it'll dry up in > > terms of supply, and the design will need to be updated.> >> > Are there any updated chipsets which would handle all the VPW timing > > and encoding including 4x? I've seen the line level stuff like the > > MC33990, but you have to do all the pulewidth management at the micro > > side. I think that would be a great way to go, but would put more > > burden on the firmware development side. Maybe eventually, but for a > > quick-hit, the 68HC58 should cut it. Open to other ideas though.> >> > Best regards,> > Craig Moates> >> >> > ----- Original Message ----- From: "Bill Shaw" <b.shaw at comcast.net>> > To: <gmecm at diy-efi.org>> > Sent: Thursday, December 21, 2006 7:32 AM> > Subject: Re: [Gmecm] Any USB developers out there?> >> >> >> Hi Craig,> >>> >> What schematic capture are you using for this? The first problem I > >> see is the 68hc58, Freescale says it's obsolete and not recommended > >> for new designs.> >>> >> Best,> >>> >> Bill> >>> >> Craig Moates wrote:> >>> Steve,> >>>> >>> I've put together an 'alternate' layout for USB-to-VPW. Feel free to > >>> take a look. I have yet to stitch together all of the connections, > >>> but given about an hour or so, it can be cleaned up and made to be > >>> pretty tight. Check the readme.txt for comments.> >>>> >>> I just did it from scratch, based on the datasheets and takeoffs > >>> from what I've done before. But it could be made to be pretty tight > >>> and workable, and very low cost as well. It doesn't have integrated > >>> USB in the micro, but on the other hand, it would be able to use > >>> standard COM port protocols. You could set it up with a bootloader > >>> as well to make it field updateable.> >>>> >>> Y'all are welcome to play however you like. I'm going to beat on it > >>> some more and get all the connectivity together. Might even hit on > >>> the firmware if I can find a spare day or two. Ha! Feel free to put > >>> it in as part of the Wiki for the GMECM stuff. It's a work in > >>> progress to be sure, but I figured I'd share what I had thus far.> >>>> >>> www.moates.net/projects/class2/> >>>> >>> Best regards,> >>> Craig Moates> >>>> >>>> >>> ----- Original Message ----- From: "Steve Ravet" <Steve.Ravet at arm.com>> >>> To: <gmecm at diy-efi.org>> >>> Sent: Sunday, November 19, 2006 11:41 PM> >>> Subject: RE: [Gmecm] Any USB developers out there?> >>>> >>>> >>>> >>>> >>>> -----Original Message-----> >>>> From: gmecm-bounces at diy-efi.org> >>>> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Craig Moates> >>>> Sent: Thursday, November 09, 2006 11:51 AM> >>>> To: gmecm at diy-efi.org> >>>> Subject: Re: [Gmecm] Any USB developers out there?> >>>>> >>>> Steve,> >>>>> >>>> Definitely check the crystal and capacitor areas. Those are> >>>> ceramics you are using for the 18pF set? Check that it's set> >>>> up for 18pf on the xtal desired capacitance?> >>>> >>> The crystal is 20 MHz 18pf according to the digikey datasheet. They're> >>> ceramic caps.> >>>> >>> I don't know what the problem with the crystal circuit is, but I > >>> removed> >>> it and used a 4 MHz OSC instead, changing the firmware accordingly, and> >>> now it works. I tried with and without the load resistor (on the> >>> crystal) but no change. The demo board has an external load resistor> >>> but the data sheet shows a resistor internal to the part.> >>>> >>> I decided that I want USB power after all so I can reflash the PIC> >>> without external power. You mentioned the circuit you use but I can't> >>> find the note now. What is it?> >>>> >>> Craig, what do you use for schematic capture and PCB layout?> >>>> >>> Maybe there'll be a USB <-> VPW project working by Christmas now...> >>>> >>> thanks for the suggestions everyone,> >>>> >>> --steve> > _______________________________________________> Gmecm mailing list> Gmecm at diy-efi.org> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm> Main WWW page: http://www.diy-efi.org/gmecm
_________________________________________________________________
Type your favorite song.? Get a customized station.? Try MSN Radio powered by Pandora.
http://radio.msn.com

From b.shaw at comcast.net  Thu Dec 21 11:26:48 2006
From: b.shaw at comcast.net (Bill Shaw)
Date: Thu, 21 Dec 2006 12:26:48 -0500
Subject: [Gmecm] Any USB developers out there?
In-Reply-To: <BAY124-W44C325175B2F7CD2B45D56A3CE0@phx.gbl>
References: <BAY124-W44C325175B2F7CD2B45D56A3CE0@phx.gbl>
Message-ID: <458AC3D8.2060702@comcast.net>

I've been playing with it also.  It keeps up with the '06 and '07 
Corvette communications pretty well too.  Things get real busy on that 
bus once the engine starts.

It's difficult to compete on price with low volume products like this.

Bill

Jay Shroff wrote:
> There seems to be a competitor to ELM who posted on this list
>  
> www.obdpros.com
>  
> Maybe they are willing to provide the micro's at a much lower cost than ELM. I have been playing around with one of those devices and it seems to be able to keep up with a pretty busy J1850 bus on a 1996 Chevy Avalanche.
> Jay
>
>
>   



From Steve.Ravet at arm.com  Thu Dec 21 11:36:25 2006
From: Steve.Ravet at arm.com (Steve Ravet)
Date: Thu, 21 Dec 2006 11:36:25 -0600
Subject: [Gmecm] Any USB developers out there?
Message-ID: <DBB2E4C4173F1749B6C74341406117830180FA81@NASDAQ.usa.Arm.com>

 

> -----Original Message-----
> From: gmecm-bounces at diy-efi.org 
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Bill Shaw
> Sent: Thursday, December 21, 2006 7:32 AM
> To: gmecm at diy-efi.org
> Subject: Re: [Gmecm] Any USB developers out there?
> 
> Hi Craig,
> 
> What schematic capture are you using for this?  The first 
> problem I see is the 68hc58,  Freescale says it's obsolete 
> and not recommended for new designs.
> 
> Best,
> 
> Bill

Bill, I've been meaning to ask you about this.  BDLC is one thing, it
doesn't include a line driver and it doesn't do block transfers or 4x
mode.  68hc58 is a DLC, and if you go to freescale.com and put xc68hc58
into the search field you come up to a page with 4 DLC parts that say
active, and in fact have all been transitioned to ROHS.  I'm not sure
that it is obsolete, given that it's the only choice for PCM and for
reflashing equipment, since it has support for blocks and 4x.

--steve



From b.shaw at comcast.net  Thu Dec 21 11:48:50 2006
From: b.shaw at comcast.net (Bill Shaw)
Date: Thu, 21 Dec 2006 12:48:50 -0500
Subject: [Gmecm] Any USB developers out there?
In-Reply-To: <DBB2E4C4173F1749B6C74341406117830180FA81@NASDAQ.usa.Arm.com>
References: <DBB2E4C4173F1749B6C74341406117830180FA81@NASDAQ.usa.Arm.com>
Message-ID: <458AC902.2030409@comcast.net>

Hi Steve,

That's direct from the local Freescale factory reps. I've been working 
with them on a new production design but they no longer have a good, low 
cost solution.  Since GM's no longer using VPW in new designs it figures 
that Freescale won't be making them any more.

Bill

Steve Ravet wrote:
>  
>
>   
>> -----Original Message-----
>> From: gmecm-bounces at diy-efi.org 
>> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Bill Shaw
>> Sent: Thursday, December 21, 2006 7:32 AM
>> To: gmecm at diy-efi.org
>> Subject: Re: [Gmecm] Any USB developers out there?
>>
>> Hi Craig,
>>
>> What schematic capture are you using for this?  The first 
>> problem I see is the 68hc58,  Freescale says it's obsolete 
>> and not recommended for new designs.
>>
>> Best,
>>
>> Bill
>>     
>
> Bill, I've been meaning to ask you about this.  BDLC is one thing, it
> doesn't include a line driver and it doesn't do block transfers or 4x
> mode.  68hc58 is a DLC, and if you go to freescale.com and put xc68hc58
> into the search field you come up to a page with 4 DLC parts that say
> active, and in fact have all been transitioned to ROHS.  I'm not sure
> that it is obsolete, given that it's the only choice for PCM and for
> reflashing equipment, since it has support for blocks and 4x.
>
> --steve
>
>   



From b.shaw at comcast.net  Thu Dec 21 11:51:15 2006
From: b.shaw at comcast.net (Bill Shaw)
Date: Thu, 21 Dec 2006 12:51:15 -0500
Subject: [Gmecm] Any USB developers out there?
In-Reply-To: <DBB2E4C4173F1749B6C74341406117830180FA81@NASDAQ.usa.Arm.com>
References: <DBB2E4C4173F1749B6C74341406117830180FA81@NASDAQ.usa.Arm.com>
Message-ID: <458AC993.5070902@comcast.net>

BTW - there are probably enough parts in distribution to supply hobbyist 
demand for a while (like Craig's personal stash),I just can't base a new 
production design on them.

Best,

Bill

Steve Ravet wrote:
>  
>
>   
>> -----Original Message-----
>> From: gmecm-bounces at diy-efi.org 
>> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Bill Shaw
>> Sent: Thursday, December 21, 2006 7:32 AM
>> To: gmecm at diy-efi.org
>> Subject: Re: [Gmecm] Any USB developers out there?
>>
>> Hi Craig,
>>
>> What schematic capture are you using for this?  The first 
>> problem I see is the 68hc58,  Freescale says it's obsolete 
>> and not recommended for new designs.
>>
>> Best,
>>
>> Bill
>>     
>
> Bill, I've been meaning to ask you about this.  BDLC is one thing, it
> doesn't include a line driver and it doesn't do block transfers or 4x
> mode.  68hc58 is a DLC, and if you go to freescale.com and put xc68hc58
> into the search field you come up to a page with 4 DLC parts that say
> active, and in fact have all been transitioned to ROHS.  I'm not sure
> that it is obsolete, given that it's the only choice for PCM and for
> reflashing equipment, since it has support for blocks and 4x.
>
> --steve
>
>   



From wopontour at hotmail.com  Thu Dec 21 12:09:50 2006
From: wopontour at hotmail.com (WopOnTour)
Date: Thu, 21 Dec 2006 11:09:50 -0700
Subject: [Gmecm] Any USB developers out there?
References: <BAY124-W44C325175B2F7CD2B45D56A3CE0@phx.gbl>
	<458AC3D8.2060702@comcast.net>
Message-ID: <BAY122-DAV1504DBB0CE25F9371D7A9EBACE0@phx.gbl>

It works with CAN/GM LAN??????
(as used in the 06-07 Vette)
WOT
----- Original Message ----- 
From: "Bill Shaw" <b.shaw at comcast.net>
To: <gmecm at diy-efi.org>
Sent: Thursday, December 21, 2006 10:26 AM
Subject: Re: [Gmecm] Any USB developers out there?


> I've been playing with it also.  It keeps up with the '06 and '07 Corvette 
> communications pretty well too.  Things get real busy on that bus once the 
> engine starts.
>
> It's difficult to compete on price with low volume products like this.
>
> Bill
>
> Jay Shroff wrote:
>> There seems to be a competitor to ELM who posted on this list
>>  www.obdpros.com
>>  Maybe they are willing to provide the micro's at a much lower cost than 
>> ELM. I have been playing around with one of those devices and it seems to 
>> be able to keep up with a pretty busy J1850 bus on a 1996 Chevy 
>> Avalanche.
>> Jay
>>
>>
>>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 



From b.shaw at comcast.net  Thu Dec 21 12:22:06 2006
From: b.shaw at comcast.net (Bill Shaw)
Date: Thu, 21 Dec 2006 13:22:06 -0500
Subject: [Gmecm] Any USB developers out there?
In-Reply-To: <BAY122-DAV1504DBB0CE25F9371D7A9EBACE0@phx.gbl>
References: <BAY124-W44C325175B2F7CD2B45D56A3CE0@phx.gbl>	<458AC3D8.2060702@comcast.net>
	<BAY122-DAV1504DBB0CE25F9371D7A9EBACE0@phx.gbl>
Message-ID: <458AD0CE.5070806@comcast.net>

'06/'07 Vette is using J1850 for slow stuff and GMLAN for ECM/ABS/fast 
stuff. The BCM acts as a bridge.  It still has the same old OBDII port 
with 10.5kbps vpw.  The '08s are all CAN/GMLAN.

Bill

WopOnTour wrote:
> It works with CAN/GM LAN??????
> (as used in the 06-07 Vette)
> WOT
> ----- Original Message ----- From: "Bill Shaw" <b.shaw at comcast.net>
> To: <gmecm at diy-efi.org>
> Sent: Thursday, December 21, 2006 10:26 AM
> Subject: Re: [Gmecm] Any USB developers out there?
>
>
>> I've been playing with it also.  It keeps up with the '06 and '07 
>> Corvette communications pretty well too.  Things get real busy on 
>> that bus once the engine starts.
>>
>> It's difficult to compete on price with low volume products like this.
>>
>> Bill
>>
>> Jay Shroff wrote:
>>> There seems to be a competitor to ELM who posted on this list
>>>  www.obdpros.com
>>>  Maybe they are willing to provide the micro's at a much lower cost 
>>> than ELM. I have been playing around with one of those devices and 
>>> it seems to be able to keep up with a pretty busy J1850 bus on a 
>>> 1996 Chevy Avalanche.
>>> Jay
>>>
>>>



From jshroff at hotmail.com  Thu Dec 21 12:28:40 2006
From: jshroff at hotmail.com (Jay Shroff)
Date: Thu, 21 Dec 2006 18:28:40 +0000
Subject: [Gmecm] Any USB developers out there?
Message-ID: <BAY124-W58B69F614CDE8AA7BA970AA3CE0@phx.gbl>

> > Bill, I've been meaning to ask you about this. BDLC is one thing, it> doesn't include a line driver and it doesn't do block transfers or 4x> mode. 68hc58 is a DLC, and if you go to freescale.com and put xc68hc58> into the search field you come up to a page with 4 DLC parts that say> active, and in fact have all been transitioned to ROHS. I'm not sure> that it is obsolete, given that it's the only choice for PCM and for> reflashing equipment, since it has support for blocks and 4x.> > --steve> Hi Steve, 
 
Do you have any doc's/Spec's on what you mean by blocks, I have played around with a J1850 implementation and getting 4x is not that difficult, but not sure what you mean by blocks.
 
Jay
_________________________________________________________________
Fixing up the home? Live Search can help.
http://imagine-windowslive.com/search/kits/default.aspx?kit=improve&locale=en-US&source=wlmemailtaglinenov06

From b.shaw at comcast.net  Thu Dec 21 12:36:04 2006
From: b.shaw at comcast.net (Bill Shaw)
Date: Thu, 21 Dec 2006 13:36:04 -0500
Subject: [Gmecm] Any USB developers out there?
In-Reply-To: <BAY124-W58B69F614CDE8AA7BA970AA3CE0@phx.gbl>
References: <BAY124-W58B69F614CDE8AA7BA970AA3CE0@phx.gbl>
Message-ID: <458AD414.2010701@comcast.net>

Hi Jay,

I was referring to microprocessors with integrated BDLC peripherals 
(BLDC blocks).  MC908AZ32A is an example of an obsolete microprocessor 
with a BDLC block.

Bill

Jay Shroff wrote:
>>> Bill, I've been meaning to ask you about this. BDLC is one thing, it> doesn't include a line driver and it doesn't do block transfers or 4x> mode. 68hc58 is a DLC, and if you go to freescale.com and put xc68hc58> into the search field you come up to a page with 4 DLC parts that say> active, and in fact have all been transitioned to ROHS. I'm not sure> that it is obsolete, given that it's the only choice for PCM and for> reflashing equipment, since it has support for blocks and 4x.> > --steve> Hi Steve, 
>>>       
>  
> Do you have any doc's/Spec's on what you mean by blocks, I have played around with a J1850 implementation and getting 4x is not that difficult, but not sure what you mean by blocks.
>  
> Jay
>   



From jshroff at hotmail.com  Thu Dec 21 13:34:19 2006
From: jshroff at hotmail.com (Jay Shroff)
Date: Thu, 21 Dec 2006 19:34:19 +0000
Subject: [Gmecm] Any USB developers out there?
Message-ID: <BAY124-W4349B9F896BF5AB005FBE8A3CE0@phx.gbl>

> Date: Thu, 21 Dec 2006 13:36:04 -0500> From: b.shaw at comcast.net> To: gmecm at diy-efi.org> Subject: Re: [Gmecm] Any USB developers out there?> > Hi Jay,> > I was referring to microprocessors with integrated BDLC peripherals > (BLDC blocks). MC908AZ32A is an example of an obsolete microprocessor > with a BDLC block.> > Bill
Hi Bill, 
 
Thanks that helps, I was thinking maybe there is a Block transfer mode in J1850 or something :-)
 
Jay
_________________________________________________________________
Get into the holiday spirit, chat with Santa on Messenger.
http://imagine-windowslive.com/minisites/santabot/default.aspx?locale=en-us

From Steve.Ravet at arm.com  Thu Dec 21 19:56:09 2006
From: Steve.Ravet at arm.com (Steve Ravet)
Date: Thu, 21 Dec 2006 19:56:09 -0600
Subject: [Gmecm] Any USB developers out there?
Message-ID: <DBB2E4C4173F1749B6C74341406117830180FB84@NASDAQ.usa.Arm.com>


> -----Original Message-----
> From: gmecm-bounces at diy-efi.org 
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Jay Shroff
> Sent: Thursday, December 21, 2006 12:29 PM
> To: gmecm at diy-efi.org
> Subject: RE: [Gmecm] Any USB developers out there?
> 
> > > Bill, I've been meaning to ask you about this. BDLC is one thing, 
> > > it> doesn't include a line driver and it doesn't do block 
> transfers 
> > > or 4x> mode. 68hc58 is a DLC, and if you go to 
> freescale.com and put 
> > > xc68hc58> into the search field you come up to a page with 4 DLC 
> > > parts that say> active, and in fact have all been transitioned to 
> > > ROHS. I'm not sure> that it is obsolete, given that it's the only 
> > > choice for PCM and for> reflashing equipment, since it 
> has support 
> > > for blocks and 4x.> > --steve> Hi Steve,
>  
> Do you have any doc's/Spec's on what you mean by blocks, I 
> have played around with a J1850 implementation and getting 4x 
> is not that difficult, but not sure what you mean by blocks.

Take a look at the 68hc58 spec on the gmecm page.  Normal J1850 messages
have a maximum length of ?? (100 bytes or so?).  Can't recall exactly.
Block mode does away with that and allows the transmitter to send as
many bytes as it wants.  Block and 4x are used together for reflashing,
to speed it up.

Having done this board I think bit banging may be a better solution,
certainly cheaper, although more work up front in the firmware.

--steve



From Steve.Ravet at arm.com  Thu Dec 21 19:57:21 2006
From: Steve.Ravet at arm.com (Steve Ravet)
Date: Thu, 21 Dec 2006 19:57:21 -0600
Subject: [Gmecm] Any USB developers out there?
Message-ID: <DBB2E4C4173F1749B6C74341406117830180FB85@NASDAQ.usa.Arm.com>

> Thanks that helps, I was thinking maybe there is a Block 
> transfer mode in J1850 or something :-)

See my previous reply.  There is a block mode "outside" J1850.

--steve



From jshroff at hotmail.com  Thu Dec 21 20:28:25 2006
From: jshroff at hotmail.com (Jay Shroff)
Date: Fri, 22 Dec 2006 02:28:25 +0000
Subject: [Gmecm] Any USB developers out there?
Message-ID: <BAY124-W514654AB039D693519DB80A3CD0@phx.gbl>


> Subject: RE: [Gmecm] Any USB developers out there?> Date: Thu, 21 Dec 2006 19:57:21 -0600> From: Steve.Ravet at arm.com> To: gmecm at diy-efi.org> > > Thanks that helps, I was thinking maybe there is a Block > > transfer mode in J1850 or something :-)> > See my previous reply. There is a block mode "outside" J1850.> > --steve> Thanks steve, I will look up the datasheet on the gmecm page.
_________________________________________________________________
Fixing up the home? Live Search can help.
http://imagine-windowslive.com/search/kits/default.aspx?kit=improve&locale=en-US&source=wlmemailtaglinenov06

From wopontour at hotmail.com  Thu Dec 21 21:54:23 2006
From: wopontour at hotmail.com (WopOnTour)
Date: Thu, 21 Dec 2006 20:54:23 -0700
Subject: [Gmecm] Any USB developers out there?
References: <BAY124-W44C325175B2F7CD2B45D56A3CE0@phx.gbl>	<458AC3D8.2060702@comcast.net><BAY122-DAV1504DBB0CE25F9371D7A9EBACE0@phx.gbl>
	<458AD0CE.5070806@comcast.net>
Message-ID: <BAY122-DAV144EC222A8D6184DD08383BACD0@phx.gbl>

Sorry, I though you had been referring to the ECM , which has been GM 
LAN/CAN since MY 2005
WOT
----- Original Message ----- 
From: "Bill Shaw" <b.shaw at comcast.net>
To: <gmecm at diy-efi.org>
Sent: Thursday, December 21, 2006 11:22 AM
Subject: Re: [Gmecm] Any USB developers out there?


> '06/'07 Vette is using J1850 for slow stuff and GMLAN for ECM/ABS/fast 
> stuff. The BCM acts as a bridge.  It still has the same old OBDII port 
> with 10.5kbps vpw.  The '08s are all CAN/GMLAN.
>
> Bill
>
> WopOnTour wrote:
>> It works with CAN/GM LAN??????
>> (as used in the 06-07 Vette)
>> WOT
>> ----- Original Message ----- From: "Bill Shaw" <b.shaw at comcast.net>
>> To: <gmecm at diy-efi.org>
>> Sent: Thursday, December 21, 2006 10:26 AM
>> Subject: Re: [Gmecm] Any USB developers out there?
>>
>>
>>> I've been playing with it also.  It keeps up with the '06 and '07 
>>> Corvette communications pretty well too.  Things get real busy on that 
>>> bus once the engine starts.
>>>
>>> It's difficult to compete on price with low volume products like this.
>>>
>>> Bill
>>>
>>> Jay Shroff wrote:
>>>> There seems to be a competitor to ELM who posted on this list
>>>>  www.obdpros.com
>>>>  Maybe they are willing to provide the micro's at a much lower cost 
>>>> than ELM. I have been playing around with one of those devices and it 
>>>> seems to be able to keep up with a pretty busy J1850 bus on a 1996 
>>>> Chevy Avalanche.
>>>> Jay
>>>>
>>>>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 



From william.lucke at highspeedlink.net  Thu Dec 21 22:15:19 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Thu, 21 Dec 2006 23:15:19 -0500
Subject: [Gmecm] $EE questions/ DRAC questions
Message-ID: <458B5BD7.4060909@highspeedlink.net>

How many people here do anything with the $EE mask ('94-'95 LT1 apps)?

We're using an 8051 to control a Caddy 500/4L80E combo in our 1990 
Suburban and we have a couple of questions on things that are stumping us.

How does one set the torque convertor to lock in manual 2nd?

The VSS originally fed a DRAC which fed the speedo and goofy 1 channel 
rear-only ABS. Since the 8051 has the capability to output almost any 
multiple of the VSS frequency, we dumped the DRAC and are running the 
speedo and ABS off a PCM output, which mostly works... except that the 
ABS is constantly flashing the brake warning light with its trouble code 
indicating that it's not getting a good VSS signal. What's different 
between the DRAC output and the 8051 speedo output and how do we get the 
ABS to work with the speedo output?



Will


From william.lucke at highspeedlink.net  Thu Dec 21 22:47:58 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Thu, 21 Dec 2006 23:47:58 -0500
Subject: [Gmecm] Fuse block pins
Message-ID: <458B637E.9050307@highspeedlink.net>

Does anyone know where to get pins for GM fuse blocks? They're kind of 
similar to pack-con pins used in '80's interior connectors, but wider 
and with different retention tangs. I need to replace one, but I don't 
know where to get it.



Will


From william.lucke at highspeedlink.net  Sun Dec 24 11:42:20 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Sun, 24 Dec 2006 12:42:20 -0500
Subject: [Gmecm] Hacking the 7429
Message-ID: <458EBBFC.60803@highspeedlink.net>

I'm finally getting started on the OBDI Cadillac Northstar computer. I'm 
looking at a reman'd unit that lists its service # as 16197429.

I've started a thread on the code and box contents here: 
http://gmecm.mine.nu/viewtopic.php?p=502#502

and have a picture of the insides here: 
http://will.saturnet.net/pictures/Northstar_PCM_16197429_marked.jpg

If anyone can help identify the IC's I've listed in the forum thread, 
that would be great. Thanks.



Will


From william.lucke at highspeedlink.net  Sun Dec 24 11:43:20 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Sun, 24 Dec 2006 12:43:20 -0500
Subject: [Gmecm] Hacking the 7429
Message-ID: <458EBC38.9080407@highspeedlink.net>

BTW, I found a page in the DIY-EFI archives ( 
http://www.retro.co.za/efi/DIY_EFI/1999/efi4-206.txt ) that lists some 
similar IC's in an 8051 (OBDI LT1 computer).



Will



From william.lucke at highspeedlink.net  Sun Dec 24 12:04:50 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Sun, 24 Dec 2006 13:04:50 -0500
Subject: [Gmecm] $EE questions/ DRAC questions
In-Reply-To: <000f01c726a1$7c0e2380$6501a8c0@HPDESKTOP>
References: <458B5BD7.4060909@highspeedlink.net>
	<000f01c726a1$7c0e2380$6501a8c0@HPDESKTOP>
Message-ID: <458EC142.40405@highspeedlink.net>

The Caddy uses an HEI dizzy. The opti-spark pickup was grafted into the
base. We're also running a TPI 400/4L60E in a Jaguar like this.

The 4L80E just has one shift solenoid inverted compared to the 4L60E.
This was accomplished caveman style with a relay.

We've played with the TCC appy/release 2nd gear tables for manual mode 
and normal mode but haven't been able to get it to work for us. I'm 
wondering if there's something we're overlooking.

Sounds like we have to put that DRAC back in. Thanks.


Will



Scott Peitzsch wrote:
>> How many people here do anything with the $EE mask ('94-'95 LT1 apps)?
> 
> I use it quite a bit - owned a few LT! cars and have a few LT1 swaps under
> my belt.
> 
>> We're using an 8051 to control a Caddy 500/4L80E combo in our 1990 
>> Suburban and we have a couple of questions on things that are stumping 
>> us.
> 
> Nice!  Did you adapt the Opti wheel and sensor to the inside of a caddy
> distributor?
> 
> Also, did you correct the inconsistencies in the shift logic between the 
> 4L60E
> and 4L80E in the transmission, in the PCM code, or using an enternal 
> hardware?
> Controlling a 4L80E trans using a PCM originally intended for a 4L60E is a
> project I've had on the back burner for a while now - need to get to it 
> one of
> these days!
> 
>> How does one set the torque convertor to lock in manual 2nd?
> 
> The latest TunerCat definition for the $EE mask has Manual Mode TCC apply
> and release tables that include a 2nd gear column.  Have you tried these 
> yet?
> All of the stock calibrations I;'ve seen have the apply set to 255 in 
> all cells, meaning
> it won't lock up in 2nd manual.
> 
>> The VSS originally fed a DRAC which fed the speedo and goofy 1 channel 
>> rear-only ABS. Since the 8051 has the capability to output almost any 
>> multiple of the VSS frequency, we dumped the DRAC and are running the 
>> speedo and ABS off a PCM output, which mostly works... except that the 
>> ABS is constantly flashing the brake warning light with its trouble 
>> code indicating that it's not getting a good VSS signal. What's 
>> different between the DRAC output and the 8051 speedo output and how 
>> do we get the ABS to work with the speedo output?
> 
> The ABS output from your original DRAC module produced 128,000 PPM.
> The speedo output from that same DRAC module produced 2,000 PPM.  The
> speedo output from the LT1 PCM is also going to produce 2,000 PPM.  The
> speedo and ABS can't be run from the same PCM output since they're looking
> for different pulse ratios.  You may have to reinstall the DRAC just to 
> generate
> the ABS output.  Both the LT1 PCM VSS input and DRAC can be wired to the
> VSS - BTDT.
> 
> Hope this helps!
> 
> -Scott
> 
> 
> 




From craig.moates at cox.net  Mon Dec 25 15:01:01 2006
From: craig.moates at cox.net (Craig Moates)
Date: Mon, 25 Dec 2006 15:01:01 -0600
Subject: [Gmecm] Any USB developers out there?
References: <DBB2E4C4173F1749B6C74341406117830180FA81@NASDAQ.usa.Arm.com>
Message-ID: <003401c72867$c8c9a830$b800a8c0@antec>

Folks,

I updated the layout, and it's probably ready for a proto run. Check it out if you like:
www.moates.net/projects/
Got tired of trying to squeeze those beefy 1206s in there so went to mostly 0402. They're doable with magnifier and tweezers.

All the components are specified, laid out pretty well, and labeled on the schematic and silkscreen.

I'll start working on the firmware shortly. Prefer C++ or ASM? Guess I'll make it compatible with some of the 'other' stuff out 
there.

Best regards,
Craig Moates


----- Original Message ----- 
From: "Steve Ravet" <Steve.Ravet at arm.com>
To: <gmecm at diy-efi.org>
Sent: Thursday, December 21, 2006 11:36 AM
Subject: RE: [Gmecm] Any USB developers out there?




> -----Original Message-----
> From: gmecm-bounces at diy-efi.org
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Bill Shaw
> Sent: Thursday, December 21, 2006 7:32 AM
> To: gmecm at diy-efi.org
> Subject: Re: [Gmecm] Any USB developers out there?
>
> Hi Craig,
>
> What schematic capture are you using for this?  The first
> problem I see is the 68hc58,  Freescale says it's obsolete
> and not recommended for new designs.
>
> Best,
>
> Bill

Bill, I've been meaning to ask you about this.  BDLC is one thing, it
doesn't include a line driver and it doesn't do block transfers or 4x
mode.  68hc58 is a DLC, and if you go to freescale.com and put xc68hc58
into the search field you come up to a page with 4 DLC parts that say
active, and in fact have all been transitioned to ROHS.  I'm not sure
that it is obsolete, given that it's the only choice for PCM and for
reflashing equipment, since it has support for blocks and 4x.

--steve

_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm



From craig.moates at cox.net  Mon Dec 25 16:00:47 2006
From: craig.moates at cox.net (Craig Moates)
Date: Mon, 25 Dec 2006 16:00:47 -0600
Subject: [Gmecm] Any USB developers out there?
References: <DBB2E4C4173F1749B6C74341406117830180FA81@NASDAQ.usa.Arm.com>
	<003401c72867$c8c9a830$b800a8c0@antec>
Message-ID: <003d01c72870$221b9670$b800a8c0@antec>

Added info to GMECM Twiki along with some other stuff:
http://www.diy-efi.org/twiki/bin/view.pl/Gmecm/GmecmProjects

Best regards,
Craig Moates


----- Original Message ----- 
From: "Craig Moates" <craig.moates at cox.net>
To: <gmecm at diy-efi.org>
Sent: Monday, December 25, 2006 3:01 PM
Subject: Re: [Gmecm] Any USB developers out there?


> Folks,
> 
> I updated the layout, and it's probably ready for a proto run. Check it out if you like:
> www.moates.net/projects/
> Got tired of trying to squeeze those beefy 1206s in there so went to mostly 0402. They're doable with magnifier and tweezers.
> 
> All the components are specified, laid out pretty well, and labeled on the schematic and silkscreen.
> 
> I'll start working on the firmware shortly. Prefer C++ or ASM? Guess I'll make it compatible with some of the 'other' stuff out 
> there.
> 
> Best regards,
> Craig Moates
> 
> 
> ----- Original Message ----- 
> From: "Steve Ravet" <Steve.Ravet at arm.com>
> To: <gmecm at diy-efi.org>
> Sent: Thursday, December 21, 2006 11:36 AM
> Subject: RE: [Gmecm] Any USB developers out there?
> 
> 
> 
> 
>> -----Original Message-----
>> From: gmecm-bounces at diy-efi.org
>> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Bill Shaw
>> Sent: Thursday, December 21, 2006 7:32 AM
>> To: gmecm at diy-efi.org
>> Subject: Re: [Gmecm] Any USB developers out there?
>>
>> Hi Craig,
>>
>> What schematic capture are you using for this?  The first
>> problem I see is the 68hc58,  Freescale says it's obsolete
>> and not recommended for new designs.
>>
>> Best,
>>
>> Bill
> 
> Bill, I've been meaning to ask you about this.  BDLC is one thing, it
> doesn't include a line driver and it doesn't do block transfers or 4x
> mode.  68hc58 is a DLC, and if you go to freescale.com and put xc68hc58
> into the search field you come up to a page with 4 DLC parts that say
> active, and in fact have all been transitioned to ROHS.  I'm not sure
> that it is obsolete, given that it's the only choice for PCM and for
> reflashing equipment, since it has support for blocks and 4x.
> 
> --steve
> 
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm


From Steve.Ravet at arm.com  Wed Dec 27 01:14:31 2006
From: Steve.Ravet at arm.com (Steve Ravet)
Date: Wed, 27 Dec 2006 01:14:31 -0600
Subject: [Gmecm] Any USB developers out there?
Message-ID: <DBB2E4C4173F1749B6C74341406117830180FBE0@NASDAQ.usa.Arm.com>

Hey Craig, thanks for sharing.  I have a few questions:

Is the 9 pin to OBD2 cable something that is standard or one of your
cables?  I used a DB-15 on mine, but was planning on moving to a DB-25
to allow more of the PIC pins to be pinned out (ie misc analog and
digital I/O).  But if the DB9 is standard I may switch to it.

I guess you use solder paste to do 0402?  In your experience (or anyone
else), does solder paste really go bad within a month?

After looking at yours I realized there's no reason to have the 5V
regulator in there, might as well always have the VCC stuff powered from
USB.  Eliminates parts and makes the BOM that much cheaper.  I'm also
going to use your board layout to fit the Pactec enclosure.

I'm writing my firmware in C, since microchip assembly makes my head
hurt.  As far as the host interface, I had planned on implementing the
SAE J2534-1 API.  (Yes, this is an SAE spec that specifies a windows
API).  This is a standard API for vehicle reprogramming but the API is
generic enough to work for normal scan tool operations also.  The spec
requires support for all vehicle protocols but USBVPW will only do VPW.
That SAE spec is now on the USBVPW wiki page, take a look.

What do you think your BOM cost is, including the PCB?

Speaking of PCBs, I have a number of small (couple square inches or
less) projects I've been wanting to do but it seems like most PCB houses
get offended if you do arrayed PCBs.  Is there a PCB place that will do
a 4x6 PCB with many individual circuits on it and not want to give me
all kinds of per project charges?  Otherwise the cost for these one-offs
is prohibitive.

--steve

> -----Original Message-----
> From: gmecm-bounces at diy-efi.org 
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Craig Moates
> Sent: Monday, December 25, 2006 3:01 PM
> To: gmecm at diy-efi.org
> Subject: Re: [Gmecm] Any USB developers out there?
> 
> Folks,
> 
> I updated the layout, and it's probably ready for a proto 
> run. Check it out if you like:
> www.moates.net/projects/
> Got tired of trying to squeeze those beefy 1206s in there so 
> went to mostly 0402. They're doable with magnifier and tweezers.
> 
> All the components are specified, laid out pretty well, and 
> labeled on the schematic and silkscreen.
> 
> I'll start working on the firmware shortly. Prefer C++ or 
> ASM? Guess I'll make it compatible with some of the 'other' 
> stuff out there.
> 
> Best regards,
> Craig Moates
> 
> 


From b.shaw at comcast.net  Wed Dec 27 08:05:32 2006
From: b.shaw at comcast.net (Bill Shaw)
Date: Wed, 27 Dec 2006 09:05:32 -0500
Subject: [Gmecm] Any USB developers out there?
In-Reply-To: <DBB2E4C4173F1749B6C74341406117830180FBE0@NASDAQ.usa.Arm.com>
References: <DBB2E4C4173F1749B6C74341406117830180FBE0@NASDAQ.usa.Arm.com>
Message-ID: <45927DAC.90801@comcast.net>

Hi Steve,

I've written a tutorial on surface mount assembly,  you can see it here....
http://articulationllc.home.comcast.net/sm0402.htm

Realistically,  0402 assembly is tough,  you're much better off sticking 
to 0805 if you can. 

hth,

Bill


Steve Ravet wrote:
> Hey Craig, thanks for sharing.  I have a few questions:
>
> Is the 9 pin to OBD2 cable something that is standard or one of your
> cables?  I used a DB-15 on mine, but was planning on moving to a DB-25
> to allow more of the PIC pins to be pinned out (ie misc analog and
> digital I/O).  But if the DB9 is standard I may switch to it.
>
> I guess you use solder paste to do 0402?  In your experience (or anyone
> else), does solder paste really go bad within a month?
>
> After looking at yours I realized there's no reason to have the 5V
> regulator in there, might as well always have the VCC stuff powered from
> USB.  Eliminates parts and makes the BOM that much cheaper.  I'm also
> going to use your board layout to fit the Pactec enclosure.
>
> I'm writing my firmware in C, since microchip assembly makes my head
> hurt.  As far as the host interface, I had planned on implementing the
> SAE J2534-1 API.  (Yes, this is an SAE spec that specifies a windows
> API).  This is a standard API for vehicle reprogramming but the API is
> generic enough to work for normal scan tool operations also.  The spec
> requires support for all vehicle protocols but USBVPW will only do VPW.
> That SAE spec is now on the USBVPW wiki page, take a look.
>
> What do you think your BOM cost is, including the PCB?
>
> Speaking of PCBs, I have a number of small (couple square inches or
> less) projects I've been wanting to do but it seems like most PCB houses
> get offended if you do arrayed PCBs.  Is there a PCB place that will do
> a 4x6 PCB with many individual circuits on it and not want to give me
> all kinds of per project charges?  Otherwise the cost for these one-offs
> is prohibitive.
>
> --steve
>
>   
>> -----Original Message-----
>> From: gmecm-bounces at diy-efi.org 
>> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Craig Moates
>> Sent: Monday, December 25, 2006 3:01 PM
>> To: gmecm at diy-efi.org
>> Subject: Re: [Gmecm] Any USB developers out there?
>>
>> Folks,
>>
>> I updated the layout, and it's probably ready for a proto 
>> run. Check it out if you like:
>> www.moates.net/projects/
>> Got tired of trying to squeeze those beefy 1206s in there so 
>> went to mostly 0402. They're doable with magnifier and tweezers.
>>
>> All the components are specified, laid out pretty well, and 
>> labeled on the schematic and silkscreen.
>>
>> I'll start working on the firmware shortly. Prefer C++ or 
>> ASM? Guess I'll make it compatible with some of the 'other' 
>> stuff out there.
>>
>> Best regards,
>> Craig Moates
>>
>>
>>     
> _



From craig.moates at cox.net  Wed Dec 27 11:23:29 2006
From: craig.moates at cox.net (Craig Moates)
Date: Wed, 27 Dec 2006 11:23:29 -0600
Subject: [Gmecm] Any USB developers out there?
References: <DBB2E4C4173F1749B6C74341406117830180FBE0@NASDAQ.usa.Arm.com>
Message-ID: <014301c729db$b9d43fa0$b800a8c0@antec>

Hi Steve,

Here's a link to DB9 cables:
http://www.obd2cables.com/products/
Cheapest I could find around, sub-$10 in bulk, sub-$20 even individually.

My wife and I do the 0402 all the time by hand (she doesn't like them!), it's not bad at all but it definitely takes some getting 
used to. Of course if you drop one, might as well forget about it and grab another. Just use magnifying head gear, 0.015" organic 
core solder, tweezers, and a fine tip. Regarding paste, I've used it with hot air and not had the best of luck. Little balls tend to 
float around and up under stuff (was trying to do a TQFP144 package that way). Had a lot better luck just laying it down normally 
and coming back with the wick as needed. Not sure about the aging, but I gave up on it. I suppose it's fine for volume production 
using stencils and pick-n-place.

By the way, anyone know of a water-soluble fluxed wick that works well? The stuff I use works OK, but leaves solvent-needy residues 
instead of full water clean. I'd like to have some better wicking material.

Yes, you can supply a good 100mA or so from just about any USB bus. Fairly decent power supply, not too noisy.

I did cross-check the board dimensions compared to the recommended PCB size for the Pactec enclosure, and I have some of them in 
hand. Appears to be correct, but they'll need to be trimmed pretty closely to actually fit. Also, the hole for the USB side is 
actually for an RJ11, so it'll be slightly too big. I've seen where some folks have used a rubber O-ring around the USB connector to 
center that end of the assembly in the enclosure, that works well. But the USB side of the board might need to be set back slightly 
to allow for that placement.

I'll see about setting something initial up in C then. Been trying to force myself more in that direction on new projects. Gives a 
lot more flexibility and portability.

For PCBs, if you've got anything you want run, just let me know. I can saddleback what you've got into one of my submissions. I try 
to put some 'known good' stuff in with the proto projects so that it isn't a waste if it doesn't work out. I put in 60 square inches 
of various prototypes to www.4pcb.com at least every 2 weeks under their www.33each.com offer. For the arrays, you can squeeze a lot 
of stuff into 60 square inches (their limit) and get 3 boards (their minimum) for $99 plus $50 (their upcharge for step/repeat/array 
characteristics). Lead time is 5-7 business days. Not a bad deal. There's some other deals out there, but I've had good luck with 
these guys. As long as you keep your spacing wider than 8 mils or so, and use traces of 8 mils or better and vias of 12 mils or 
better you should be OK. I usually go with 10 mil spacing, 10 mil trace width, and 16 mil via mininums.

Best regards,
Craig Moates


----- Original Message ----- 
From: "Steve Ravet" <Steve.Ravet at arm.com>
To: <gmecm at diy-efi.org>
Sent: Wednesday, December 27, 2006 1:14 AM
Subject: RE: [Gmecm] Any USB developers out there?


Hey Craig, thanks for sharing.  I have a few questions:

Is the 9 pin to OBD2 cable something that is standard or one of your
cables?  I used a DB-15 on mine, but was planning on moving to a DB-25
to allow more of the PIC pins to be pinned out (ie misc analog and
digital I/O).  But if the DB9 is standard I may switch to it.

I guess you use solder paste to do 0402?  In your experience (or anyone
else), does solder paste really go bad within a month?

After looking at yours I realized there's no reason to have the 5V
regulator in there, might as well always have the VCC stuff powered from
USB.  Eliminates parts and makes the BOM that much cheaper.  I'm also
going to use your board layout to fit the Pactec enclosure.

I'm writing my firmware in C, since microchip assembly makes my head
hurt.  As far as the host interface, I had planned on implementing the
SAE J2534-1 API.  (Yes, this is an SAE spec that specifies a windows
API).  This is a standard API for vehicle reprogramming but the API is
generic enough to work for normal scan tool operations also.  The spec
requires support for all vehicle protocols but USBVPW will only do VPW.
That SAE spec is now on the USBVPW wiki page, take a look.

What do you think your BOM cost is, including the PCB?

Speaking of PCBs, I have a number of small (couple square inches or
less) projects I've been wanting to do but it seems like most PCB houses
get offended if you do arrayed PCBs.  Is there a PCB place that will do
a 4x6 PCB with many individual circuits on it and not want to give me
all kinds of per project charges?  Otherwise the cost for these one-offs
is prohibitive.

--steve

> -----Original Message-----
> From: gmecm-bounces at diy-efi.org
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Craig Moates
> Sent: Monday, December 25, 2006 3:01 PM
> To: gmecm at diy-efi.org
> Subject: Re: [Gmecm] Any USB developers out there?
>
> Folks,
>
> I updated the layout, and it's probably ready for a proto
> run. Check it out if you like:
> www.moates.net/projects/
> Got tired of trying to squeeze those beefy 1206s in there so
> went to mostly 0402. They're doable with magnifier and tweezers.
>
> All the components are specified, laid out pretty well, and
> labeled on the schematic and silkscreen.
>
> I'll start working on the firmware shortly. Prefer C++ or
> ASM? Guess I'll make it compatible with some of the 'other'
> stuff out there.
>
> Best regards,
> Craig Moates
>
>
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm



From craig.moates at cox.net  Wed Dec 27 11:24:09 2006
From: craig.moates at cox.net (Craig Moates)
Date: Wed, 27 Dec 2006 11:24:09 -0600
Subject: [Gmecm] Any USB developers out there?
References: <DBB2E4C4173F1749B6C74341406117830180FBE0@NASDAQ.usa.Arm.com>
Message-ID: <014901c729db$d180e310$b800a8c0@antec>

I'll put together a BOM with part numbers, vendors, and pricing. I'd think it'll be pretty economical.

Best regards,
Craig Moates


----- Original Message ----- 
From: "Steve Ravet" <Steve.Ravet at arm.com>
To: <gmecm at diy-efi.org>
Sent: Wednesday, December 27, 2006 1:14 AM
Subject: RE: [Gmecm] Any USB developers out there?


Hey Craig, thanks for sharing.  I have a few questions:

Is the 9 pin to OBD2 cable something that is standard or one of your
cables?  I used a DB-15 on mine, but was planning on moving to a DB-25
to allow more of the PIC pins to be pinned out (ie misc analog and
digital I/O).  But if the DB9 is standard I may switch to it.

I guess you use solder paste to do 0402?  In your experience (or anyone
else), does solder paste really go bad within a month?

After looking at yours I realized there's no reason to have the 5V
regulator in there, might as well always have the VCC stuff powered from
USB.  Eliminates parts and makes the BOM that much cheaper.  I'm also
going to use your board layout to fit the Pactec enclosure.

I'm writing my firmware in C, since microchip assembly makes my head
hurt.  As far as the host interface, I had planned on implementing the
SAE J2534-1 API.  (Yes, this is an SAE spec that specifies a windows
API).  This is a standard API for vehicle reprogramming but the API is
generic enough to work for normal scan tool operations also.  The spec
requires support for all vehicle protocols but USBVPW will only do VPW.
That SAE spec is now on the USBVPW wiki page, take a look.

What do you think your BOM cost is, including the PCB?

Speaking of PCBs, I have a number of small (couple square inches or
less) projects I've been wanting to do but it seems like most PCB houses
get offended if you do arrayed PCBs.  Is there a PCB place that will do
a 4x6 PCB with many individual circuits on it and not want to give me
all kinds of per project charges?  Otherwise the cost for these one-offs
is prohibitive.

--steve

> -----Original Message-----
> From: gmecm-bounces at diy-efi.org 
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Craig Moates
> Sent: Monday, December 25, 2006 3:01 PM
> To: gmecm at diy-efi.org
> Subject: Re: [Gmecm] Any USB developers out there?
> 
> Folks,
> 
> I updated the layout, and it's probably ready for a proto 
> run. Check it out if you like:
> www.moates.net/projects/
> Got tired of trying to squeeze those beefy 1206s in there so 
> went to mostly 0402. They're doable with magnifier and tweezers.
> 
> All the components are specified, laid out pretty well, and 
> labeled on the schematic and silkscreen.
> 
> I'll start working on the firmware shortly. Prefer C++ or 
> ASM? Guess I'll make it compatible with some of the 'other' 
> stuff out there.
> 
> Best regards,
> Craig Moates
> 
> 
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm



From murr32 at shaw.ca  Wed Dec 27 12:00:08 2006
From: murr32 at shaw.ca (David Murray)
Date: Wed, 27 Dec 2006 11:00:08 -0700
Subject: [Gmecm] Any USB developers out there?
Message-ID: <11e4ad11dd0d.11dd0d11e4ad@shaw.ca>

Craig,

I have used an Alpha-Metals solder with a water soluble flux core, available through Digi-Key (www.digikey.com) I think.  Any reason you jumped directly to 0402 components from 1206 (or 0805)?  I have found I can squeeze most designs, with the exception of high-complexity small space boards like cell phones, using 0603 parts; though I haven't looked at your scematic or layout yet to see how tight a fit everything is.

Cheers
Dave

----- Original Message -----
From: Craig Moates <craig.moates at cox.net>
Date: Wednesday, December 27, 2006 10:23 am
Subject: Re: [Gmecm] Any USB developers out there?

> Hi Steve,
> 
> Here's a link to DB9 cables:
> http://www.obd2cables.com/products/
> Cheapest I could find around, sub-$10 in bulk, sub-$20 even 
> individually.
> My wife and I do the 0402 all the time by hand (she doesn't like 
> them!), it's not bad at all but it definitely takes some getting 
> used to. Of course if you drop one, might as well forget about it 
> and grab another. Just use magnifying head gear, 0.015" organic 
> core solder, tweezers, and a fine tip. Regarding paste, I've used 
> it with hot air and not had the best of luck. Little balls tend to 
> float around and up under stuff (was trying to do a TQFP144 
> package that way). Had a lot better luck just laying it down 
> normally 
> and coming back with the wick as needed. Not sure about the aging, 
> but I gave up on it. I suppose it's fine for volume production 
> using stencils and pick-n-place.
> 
> By the way, anyone know of a water-soluble fluxed wick that works 
> well? The stuff I use works OK, but leaves solvent-needy residues 
> instead of full water clean. I'd like to have some better wicking 
> material.
> Yes, you can supply a good 100mA or so from just about any USB 
> bus. Fairly decent power supply, not too noisy.
> 
> I did cross-check the board dimensions compared to the recommended 
> PCB size for the Pactec enclosure, and I have some of them in 
> hand. Appears to be correct, but they'll need to be trimmed pretty 
> closely to actually fit. Also, the hole for the USB side is 
> actually for an RJ11, so it'll be slightly too big. I've seen 
> where some folks have used a rubber O-ring around the USB 
> connector to 
> center that end of the assembly in the enclosure, that works well. 
> But the USB side of the board might need to be set back slightly 
> to allow for that placement.
> 
> I'll see about setting something initial up in C then. Been trying 
> to force myself more in that direction on new projects. Gives a 
> lot more flexibility and portability.
> 
> For PCBs, if you've got anything you want run, just let me know. I 
> can saddleback what you've got into one of my submissions. I try 
> to put some 'known good' stuff in with the proto projects so that 
> it isn't a waste if it doesn't work out. I put in 60 square inches 
> of various prototypes to www.4pcb.com at least every 2 weeks under 
> their www.33each.com offer. For the arrays, you can squeeze a lot 
> of stuff into 60 square inches (their limit) and get 3 boards 
> (their minimum) for $99 plus $50 (their upcharge for 
> step/repeat/array 
> characteristics). Lead time is 5-7 business days. Not a bad deal. 
> There's some other deals out there, but I've had good luck with 
> these guys. As long as you keep your spacing wider than 8 mils or 
> so, and use traces of 8 mils or better and vias of 12 mils or 
> better you should be OK. I usually go with 10 mil spacing, 10 mil 
> trace width, and 16 mil via mininums.
> 
> Best regards,
> Craig Moates
> 
> 
> ----- Original Message ----- 
> From: "Steve Ravet" <Steve.Ravet at arm.com>
> To: <gmecm at diy-efi.org>
> Sent: Wednesday, December 27, 2006 1:14 AM
> Subject: RE: [Gmecm] Any USB developers out there?
> 
> 
> Hey Craig, thanks for sharing.  I have a few questions:
> 
> Is the 9 pin to OBD2 cable something that is standard or one of your
> cables?  I used a DB-15 on mine, but was planning on moving to a 
> DB-25
> to allow more of the PIC pins to be pinned out (ie misc analog and
> digital I/O).  But if the DB9 is standard I may switch to it.
> 
> I guess you use solder paste to do 0402?  In your experience (or 
> anyoneelse), does solder paste really go bad within a month?
> 
> After looking at yours I realized there's no reason to have the 5V
> regulator in there, might as well always have the VCC stuff 
> powered from
> USB.  Eliminates parts and makes the BOM that much cheaper.  I'm also
> going to use your board layout to fit the Pactec enclosure.
> 
> I'm writing my firmware in C, since microchip assembly makes my head
> hurt.  As far as the host interface, I had planned on implementing the
> SAE J2534-1 API.  (Yes, this is an SAE spec that specifies a windows
> API).  This is a standard API for vehicle reprogramming but the 
> API is
> generic enough to work for normal scan tool operations also.  The spec
> requires support for all vehicle protocols but USBVPW will only do 
> VPW.That SAE spec is now on the USBVPW wiki page, take a look.
> 
> What do you think your BOM cost is, including the PCB?
> 
> Speaking of PCBs, I have a number of small (couple square inches or
> less) projects I've been wanting to do but it seems like most PCB 
> housesget offended if you do arrayed PCBs.  Is there a PCB place 
> that will do
> a 4x6 PCB with many individual circuits on it and not want to give me
> all kinds of per project charges?  Otherwise the cost for these 
> one-offs
> is prohibitive.
> 
> --steve
> 
> > -----Original Message-----
> > From: gmecm-bounces at diy-efi.org
> > [gmecm-bounces at diy-efi.org] On Behalf Of Craig Moates
> > Sent: Monday, December 25, 2006 3:01 PM
> > To: gmecm at diy-efi.org
> > Subject: Re: [Gmecm] Any USB developers out there?
> >
> > Folks,
> >
> > I updated the layout, and it's probably ready for a proto
> > run. Check it out if you like:
> > www.moates.net/projects/
> > Got tired of trying to squeeze those beefy 1206s in there so
> > went to mostly 0402. They're doable with magnifier and tweezers.
> >
> > All the components are specified, laid out pretty well, and
> > labeled on the schematic and silkscreen.
> >
> > I'll start working on the firmware shortly. Prefer C++ or
> > ASM? Guess I'll make it compatible with some of the 'other'
> > stuff out there.
> >
> > Best regards,
> > Craig Moates
> >
> >
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 



From davida1 at hiwaay.net  Wed Dec 27 15:01:50 2006
From: davida1 at hiwaay.net (David Allen)
Date: Wed, 27 Dec 2006 15:01:50 -0600
Subject: [Gmecm] MSD or Delco DIS
Message-ID: <006301c729fa$430b10f0$0600a8c0@yancey.com>

  Hey I have been wondering... My car does not have the proper mounting 
points for a crank trigger for use with factory DIS ignition.  I know it 
could be fabricated or adapted with medium difficulty.  I have instead gone 
with a MSD-6A ignition amplifier controlled by my ECM.
  Is this setup as strong as a Delco DIS setup?  It made a world of 
difference in high RPM power, versus a plain 1-coil HEI distributor.
  In the future I plan to build up a newer turbo motor and will probably go 
DIS at that time.
  Just curious what everyone's thoughts are on this.
Thanks,
David 



From Steve.Ravet at arm.com  Wed Dec 27 18:44:42 2006
From: Steve.Ravet at arm.com (Steve Ravet)
Date: Wed, 27 Dec 2006 18:44:42 -0600
Subject: [Gmecm] Any USB developers out there?
Message-ID: <DBB2E4C4173F1749B6C74341406117830180FBFE@NASDAQ.usa.Arm.com>

 

> -----Original Message-----
> From: gmecm-bounces at diy-efi.org 
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Bill Shaw
> Sent: Wednesday, December 27, 2006 8:06 AM
> To: gmecm at diy-efi.org
> Subject: Re: [Gmecm] Any USB developers out there?
> 
> Hi Steve,
> 
> I've written a tutorial on surface mount assembly,  you can 
> see it here....
> http://articulationllc.home.comcast.net/sm0402.htm
> 
> Realistically,  0402 assembly is tough,  you're much better 
> off sticking to 0805 if you can. 
> 
> hth,
> 
> Bill

Do you have to reflow the paste?  I needed 3 hands to solder this board:
one for solder, one for the component, and one for the iron.  I was
thinking instead to put down blobs of paste, place the component, then a
touch with the iron to melt the paste.  The reflow oven looks neat but
more than I want to get into now, especially for this fairly small
project.

--steve



From b.shaw at comcast.net  Wed Dec 27 18:49:58 2006
From: b.shaw at comcast.net (Bill Shaw)
Date: Wed, 27 Dec 2006 19:49:58 -0500
Subject: [Gmecm] Any USB developers out there?
In-Reply-To: <DBB2E4C4173F1749B6C74341406117830180FBFE@NASDAQ.usa.Arm.com>
References: <DBB2E4C4173F1749B6C74341406117830180FBFE@NASDAQ.usa.Arm.com>
Message-ID: <459314B6.7010007@comcast.net>

Sure you can use paste with the iron,  no problem.

Bill

Steve Ravet wrote:
>  
>
>   
>> -----Original Message-----
>> From: gmecm-bounces at diy-efi.org 
>> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Bill Shaw
>> Sent: Wednesday, December 27, 2006 8:06 AM
>> To: gmecm at diy-efi.org
>> Subject: Re: [Gmecm] Any USB developers out there?
>>
>> Hi Steve,
>>
>> I've written a tutorial on surface mount assembly,  you can 
>> see it here....
>> http://articulationllc.home.comcast.net/sm0402.htm
>>
>> Realistically,  0402 assembly is tough,  you're much better 
>> off sticking to 0805 if you can. 
>>
>> hth,
>>
>> Bill
>>     
>
> Do you have to reflow the paste?  I needed 3 hands to solder this board:
> one for solder, one for the component, and one for the iron.  I was
> thinking instead to put down blobs of paste, place the component, then a
> touch with the iron to melt the paste.  The reflow oven looks neat but
> more than I want to get into now, especially for this fairly small
> project.
>
> --steve
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>
>   



From DOZIERHC at aol.com  Wed Dec 27 21:28:20 2006
From: DOZIERHC at aol.com (DOZIERHC at aol.com)
Date: Wed, 27 Dec 2006 22:28:20 EST
Subject: [Gmecm] New paper on 1227749 and 1227727/30 ECMs on GM-ECM Twiki
	site
Message-ID: <c22.d66254a.32c493d4@aol.com>

I have posted a paper on the 1227749 WWW page.
 
To get there, navigate to this link:
_http://www.diy-efi.org/twiki/bin/view.pl/Gmecm/1227749_ 
(http://www.diy-efi.org/twiki/bin/view.pl/Gmecm/1227749) 
 
I think this could be of interest to several  people on the mailing list, as 
it shows a coupling association between the  1227730 series and the 1227749 
series ECMs that goes deeper than previously  thought, and opens up some 
additional possibilities for both ECMs.
 
Hank  Dozier


From craig.moates at cox.net  Thu Dec 28 13:01:01 2006
From: craig.moates at cox.net (Craig Moates)
Date: Thu, 28 Dec 2006 13:01:01 -0600
Subject: [Gmecm] Any USB developers out there?
References: <DBB2E4C4173F1749B6C74341406117830180FBFE@NASDAQ.usa.Arm.com>
Message-ID: <00c101c72ab2$84bc0b90$b800a8c0@antec>

I'll usually put solder on one of the pads by hand and then heat it up to a melt while I place the part with tweezers. Then remove 
the heat and a second later release the part from being held.

Best regards,
Craig Moates


----- Original Message ----- 
From: "Steve Ravet" <Steve.Ravet at arm.com>
To: <gmecm at diy-efi.org>
Sent: Wednesday, December 27, 2006 6:44 PM
Subject: RE: [Gmecm] Any USB developers out there?




> -----Original Message-----
> From: gmecm-bounces at diy-efi.org
> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Bill Shaw
> Sent: Wednesday, December 27, 2006 8:06 AM
> To: gmecm at diy-efi.org
> Subject: Re: [Gmecm] Any USB developers out there?
>
> Hi Steve,
>
> I've written a tutorial on surface mount assembly,  you can
> see it here....
> http://articulationllc.home.comcast.net/sm0402.htm
>
> Realistically,  0402 assembly is tough,  you're much better
> off sticking to 0805 if you can.
>
> hth,
>
> Bill

Do you have to reflow the paste?  I needed 3 hands to solder this board:
one for solder, one for the component, and one for the iron.  I was
thinking instead to put down blobs of paste, place the component, then a
touch with the iron to melt the paste.  The reflow oven looks neat but
more than I want to get into now, especially for this fairly small
project.

--steve

_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
Main WWW page: http://www.diy-efi.org/gmecm



From craig.moates at cox.net  Thu Dec 28 13:01:51 2006
From: craig.moates at cox.net (Craig Moates)
Date: Thu, 28 Dec 2006 13:01:51 -0600
Subject: [Gmecm] Any USB developers out there?
References: <11e4ad11dd0d.11dd0d11e4ad@shaw.ca>
Message-ID: <00c801c72ab2$a2469b30$b800a8c0@antec>

Dave,

Not really, just wanted to get some components in tight spots. I could probably upsize to 0603 or maybe even 0805 and get the same 
effect.

Best regards,
Craig Moates


----- Original Message ----- 
From: "David Murray" <murr32 at shaw.ca>
To: <gmecm at diy-efi.org>
Sent: Wednesday, December 27, 2006 12:00 PM
Subject: Re: [Gmecm] Any USB developers out there?


> Craig,
>
> I have used an Alpha-Metals solder with a water soluble flux core, available through Digi-Key (www.digikey.com) I think.  Any 
> reason you jumped directly to 0402 components from 1206 (or 0805)?  I have found I can squeeze most designs, with the exception of 
> high-complexity small space boards like cell phones, using 0603 parts; though I haven't looked at your scematic or layout yet to 
> see how tight a fit everything is.
>
> Cheers
> Dave
>
> ----- Original Message -----
> From: Craig Moates <craig.moates at cox.net>
> Date: Wednesday, December 27, 2006 10:23 am
> Subject: Re: [Gmecm] Any USB developers out there?
>
>> Hi Steve,
>>
>> Here's a link to DB9 cables:
>> http://www.obd2cables.com/products/
>> Cheapest I could find around, sub-$10 in bulk, sub-$20 even
>> individually.
>> My wife and I do the 0402 all the time by hand (she doesn't like
>> them!), it's not bad at all but it definitely takes some getting
>> used to. Of course if you drop one, might as well forget about it
>> and grab another. Just use magnifying head gear, 0.015" organic
>> core solder, tweezers, and a fine tip. Regarding paste, I've used
>> it with hot air and not had the best of luck. Little balls tend to
>> float around and up under stuff (was trying to do a TQFP144
>> package that way). Had a lot better luck just laying it down
>> normally
>> and coming back with the wick as needed. Not sure about the aging,
>> but I gave up on it. I suppose it's fine for volume production
>> using stencils and pick-n-place.
>>
>> By the way, anyone know of a water-soluble fluxed wick that works
>> well? The stuff I use works OK, but leaves solvent-needy residues
>> instead of full water clean. I'd like to have some better wicking
>> material.
>> Yes, you can supply a good 100mA or so from just about any USB
>> bus. Fairly decent power supply, not too noisy.
>>
>> I did cross-check the board dimensions compared to the recommended
>> PCB size for the Pactec enclosure, and I have some of them in
>> hand. Appears to be correct, but they'll need to be trimmed pretty
>> closely to actually fit. Also, the hole for the USB side is
>> actually for an RJ11, so it'll be slightly too big. I've seen
>> where some folks have used a rubber O-ring around the USB
>> connector to
>> center that end of the assembly in the enclosure, that works well.
>> But the USB side of the board might need to be set back slightly
>> to allow for that placement.
>>
>> I'll see about setting something initial up in C then. Been trying
>> to force myself more in that direction on new projects. Gives a
>> lot more flexibility and portability.
>>
>> For PCBs, if you've got anything you want run, just let me know. I
>> can saddleback what you've got into one of my submissions. I try
>> to put some 'known good' stuff in with the proto projects so that
>> it isn't a waste if it doesn't work out. I put in 60 square inches
>> of various prototypes to www.4pcb.com at least every 2 weeks under
>> their www.33each.com offer. For the arrays, you can squeeze a lot
>> of stuff into 60 square inches (their limit) and get 3 boards
>> (their minimum) for $99 plus $50 (their upcharge for
>> step/repeat/array
>> characteristics). Lead time is 5-7 business days. Not a bad deal.
>> There's some other deals out there, but I've had good luck with
>> these guys. As long as you keep your spacing wider than 8 mils or
>> so, and use traces of 8 mils or better and vias of 12 mils or
>> better you should be OK. I usually go with 10 mil spacing, 10 mil
>> trace width, and 16 mil via mininums.
>>
>> Best regards,
>> Craig Moates
>>
>>
>> ----- Original Message ----- 
>> From: "Steve Ravet" <Steve.Ravet at arm.com>
>> To: <gmecm at diy-efi.org>
>> Sent: Wednesday, December 27, 2006 1:14 AM
>> Subject: RE: [Gmecm] Any USB developers out there?
>>
>>
>> Hey Craig, thanks for sharing.  I have a few questions:
>>
>> Is the 9 pin to OBD2 cable something that is standard or one of your
>> cables?  I used a DB-15 on mine, but was planning on moving to a
>> DB-25
>> to allow more of the PIC pins to be pinned out (ie misc analog and
>> digital I/O).  But if the DB9 is standard I may switch to it.
>>
>> I guess you use solder paste to do 0402?  In your experience (or
>> anyoneelse), does solder paste really go bad within a month?
>>
>> After looking at yours I realized there's no reason to have the 5V
>> regulator in there, might as well always have the VCC stuff
>> powered from
>> USB.  Eliminates parts and makes the BOM that much cheaper.  I'm also
>> going to use your board layout to fit the Pactec enclosure.
>>
>> I'm writing my firmware in C, since microchip assembly makes my head
>> hurt.  As far as the host interface, I had planned on implementing the
>> SAE J2534-1 API.  (Yes, this is an SAE spec that specifies a windows
>> API).  This is a standard API for vehicle reprogramming but the
>> API is
>> generic enough to work for normal scan tool operations also.  The spec
>> requires support for all vehicle protocols but USBVPW will only do
>> VPW.That SAE spec is now on the USBVPW wiki page, take a look.
>>
>> What do you think your BOM cost is, including the PCB?
>>
>> Speaking of PCBs, I have a number of small (couple square inches or
>> less) projects I've been wanting to do but it seems like most PCB
>> housesget offended if you do arrayed PCBs.  Is there a PCB place
>> that will do
>> a 4x6 PCB with many individual circuits on it and not want to give me
>> all kinds of per project charges?  Otherwise the cost for these
>> one-offs
>> is prohibitive.
>>
>> --steve
>>
>> > -----Original Message-----
>> > From: gmecm-bounces at diy-efi.org
>> > [gmecm-bounces at diy-efi.org] On Behalf Of Craig Moates
>> > Sent: Monday, December 25, 2006 3:01 PM
>> > To: gmecm at diy-efi.org
>> > Subject: Re: [Gmecm] Any USB developers out there?
>> >
>> > Folks,
>> >
>> > I updated the layout, and it's probably ready for a proto
>> > run. Check it out if you like:
>> > www.moates.net/projects/
>> > Got tired of trying to squeeze those beefy 1206s in there so
>> > went to mostly 0402. They're doable with magnifier and tweezers.
>> >
>> > All the components are specified, laid out pretty well, and
>> > labeled on the schematic and silkscreen.
>> >
>> > I'll start working on the firmware shortly. Prefer C++ or
>> > ASM? Guess I'll make it compatible with some of the 'other'
>> > stuff out there.
>> >
>> > Best regards,
>> > Craig Moates
>> >
>> >
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm 



From william.lucke at highspeedlink.net  Thu Dec 28 14:34:05 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Thu, 28 Dec 2006 15:34:05 -0500
Subject: [Gmecm] Re: MSD or Delco DIS
Message-ID: <45942A3D.7010505@highspeedlink.net>

What kind of engine? There are MSD amplifiers compatible with DIS as well.


Will


> From: "David Allen" <davida1 at hiwaay.net>
> Subject: [Gmecm] MSD or Delco DIS
> 
>   Hey I have been wondering... My car does not have the proper mounting 
> points for a crank trigger for use with factory DIS ignition.  I know it 
> could be fabricated or adapted with medium difficulty.  I have instead gone 
> with a MSD-6A ignition amplifier controlled by my ECM.
>   Is this setup as strong as a Delco DIS setup?  It made a world of 
> difference in high RPM power, versus a plain 1-coil HEI distributor.
>   In the future I plan to build up a newer turbo motor and will probably go 
> DIS at that time.
>   Just curious what everyone's thoughts are on this.
> Thanks,
> David 


From davida1 at hiwaay.net  Thu Dec 28 15:03:14 2006
From: davida1 at hiwaay.net (David Allen)
Date: Thu, 28 Dec 2006 15:03:14 -0600
Subject: [Gmecm] Re: MSD or Delco DIS
References: <45942A3D.7010505@highspeedlink.net>
Message-ID: <000e01c72ac3$a0c5b7d0$0700a8c0@yancey.com>

  It's an ironhead MPFI 2.8, with a distributor. Turbo intercooled.  I would 
be just as happy with a standard Delco DIS setup if it will ignite my 
turbocharged engine.
  See http://home.hiwaay.net/~davida1/turbo2.htm for the engine information. 
or http://home.hiwaay.net/~davida1/superc.htm.
Thanks!
David


----- Original Message ----- 
From: "William Lucke" <william.lucke at highspeedlink.net>
To: <gmecm at diy-efi.org>
Sent: Thursday, December 28, 2006 2:34 PM
Subject: [Gmecm] Re: MSD or Delco DIS


> What kind of engine? There are MSD amplifiers compatible with DIS as well.
>
>
> Will
>
>
>> From: "David Allen" <davida1 at hiwaay.net>
>> Subject: [Gmecm] MSD or Delco DIS
>>
>>   Hey I have been wondering... My car does not have the proper mounting 
>> points for a crank trigger for use with factory DIS ignition.  I know it 
>> could be fabricated or adapted with medium difficulty.  I have instead 
>> gone with a MSD-6A ignition amplifier controlled by my ECM.
>>   Is this setup as strong as a Delco DIS setup?  It made a world of 
>> difference in high RPM power, versus a plain 1-coil HEI distributor.
>>   In the future I plan to build up a newer turbo motor and will probably 
>> go DIS at that time.
>>   Just curious what everyone's thoughts are on this.
>> Thanks,
>> David
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 



From pmkls1 at yahoo.com  Fri Dec 29 01:00:29 2006
From: pmkls1 at yahoo.com (Phillip Kuhn)
Date: Thu, 28 Dec 2006 23:00:29 -0800 (PST)
Subject: [Gmecm] Re: MSD or Delco DIS
In-Reply-To: <000e01c72ac3$a0c5b7d0$0700a8c0@yancey.com>
Message-ID: <221582.20397.qm@web54608.mail.yahoo.com>

DIS is definately the way to go and like was mentioned
earlier some msd boxes are designed to be compatible
with it which would make it even better. The main
thing is fabricating a crank trigger which shouldnt be
that bad really. There are a few companies that sell
pre-fabricated crank wheels in different sizes that
just need a little work to be mounted correctly. DIS
works great no matter what the engine setup be.
Granted, it does require some fab work, but the
rewards are worth it. Try accufabracing.com they
(along with several others) sell wheels for the crank
trigger in various sizes.


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 


From pmkls1 at yahoo.com  Fri Dec 29 01:01:43 2006
From: pmkls1 at yahoo.com (Phillip Kuhn)
Date: Thu, 28 Dec 2006 23:01:43 -0800 (PST)
Subject: [Gmecm] Re: MSD or Delco DIS
In-Reply-To: <000e01c72ac3$a0c5b7d0$0700a8c0@yancey.com>
Message-ID: <209796.42989.qm@web54602.mail.yahoo.com>

BTW, im curious what type of vehicle this is in. Is is
a s10 or camaro or an older front drive car ?


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 


From davida1 at hiwaay.net  Fri Dec 29 08:48:34 2006
From: davida1 at hiwaay.net (David Allen)
Date: Fri, 29 Dec 2006 08:48:34 -0600
Subject: [Gmecm] Re: MSD or Delco DIS
References: <209796.42989.qm@web54602.mail.yahoo.com>
Message-ID: <001001c72b58$6c3111a0$0700a8c0@yancey.com>


> BTW, im curious what type of vehicle this is in. Is is
> a s10 or camaro or an older front drive car ?

  It'a an older FWD car - a Buick Century.  Maybe this didn't go through. 
http://home.hiwaay.net/~davida1/superc.htm shows the car and it has a link 
to the engine setup.
  I'm not in this for looks or to be able to say "I have an MSD ignition" to 
the riceboys.  I just wanted something that works properly with my setup.  A 
stock 1-coil distributor did NOT work properly... The MSD was a very 
non-invasive drop-in solution that absolutely _fixed_ the problem.
  The MSD box works exceptionally well, but my next motor will be a newer 
one with factory DIS. (maybe even a 3900!)
  I know the GN guys have a standard DIS and boost 20 PSI with it and have 
plenty of ignition.
  Thanks,
David



From william.lucke at highspeedlink.net  Sat Dec 30 18:59:36 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Sat, 30 Dec 2006 19:59:36 -0500
Subject: [Gmecm] Re: Gmecm Digest, Vol 22, Issue 32
Message-ID: <45970B78.9090607@highspeedlink.net>

That's a cool setup. Have you ever taken it to a drag strip and gotten 
numbers?
The 3900 and '06 3500 both have variable cam phasing. This necessitates 
an advanced ECM. The latest engine that would be compatible with your 
current (or any OBDI) ECM would be an '04-'05 3500. Stock 3400's have 
made over 300 WHP turbocharged.
MSD makes multi-channel boxes with adapters that mount between the DIS 
module and the coils.
Your page mentions an aftermarket datalogging system... what system is that?


Will


> From: "David Allen" <davida1 at hiwaay.net>
> Subject: Re: [Gmecm] Re: MSD or Delco DIS
> 
>> BTW, im curious what type of vehicle this is in. Is is
>> a s10 or camaro or an older front drive car ?
> 
>   It'a an older FWD car - a Buick Century.  Maybe this didn't go through. 
> http://home.hiwaay.net/~davida1/superc.htm shows the car and it has a link 
> to the engine setup.
>   I'm not in this for looks or to be able to say "I have an MSD ignition" to 
> the riceboys.  I just wanted something that works properly with my setup.  A 
> stock 1-coil distributor did NOT work properly... The MSD was a very 
> non-invasive drop-in solution that absolutely _fixed_ the problem.
>   The MSD box works exceptionally well, but my next motor will be a newer 
> one with factory DIS. (maybe even a 3900!)
>   I know the GN guys have a standard DIS and boost 20 PSI with it and have 
> plenty of ignition.
>   Thanks,
> David



From davida1 at hiwaay.net  Sat Dec 30 19:59:33 2006
From: davida1 at hiwaay.net (David Allen)
Date: Sat, 30 Dec 2006 19:59:33 -0600
Subject: [Gmecm] Re: Gmecm Digest, Vol 22, Issue 32
References: <45970B78.9090607@highspeedlink.net>
Message-ID: <005101c72c7f$64de7dc0$0700a8c0@yancey.com>

  I had planned to fully utilize the VVT - will be another challenge I look 
forward to learning from.
  Haven't taken it to the track because there are no tracks here that I know 
of; and I'm not in the loop of people locally to make such an outing.  That 
day will come however.
  I'm using a Tech Edge 2B0 datalogger for this car.  Nothing high-tech; I 
have to review the data in Excel and adjust the tables manually.
  As for the VVT; I can build a controller which will look at cam reference 
and crank reference and hold the VVT at whatever position is commanded. 
This could take a duty-cycle signal from the ECM.  It could possible use the 
PWM output, and table in the BIN originally for EGR to allow an older ECM to 
work. Something to think about anyway.
  I'd rather not have an MSD system unless it is necessary.  It was 
necessary with the distributor but I bet DIS will be strong enough as-is.
  Thanks!
David




- ---- Original Message ----- 
From: "William Lucke" <william.lucke at highspeedlink.net>
To: <gmecm at diy-efi.org>
Sent: Saturday, December 30, 2006 6:59 PM
Subject: [Gmecm] Re: Gmecm Digest, Vol 22, Issue 32


> That's a cool setup. Have you ever taken it to a drag strip and gotten 
> numbers?
> The 3900 and '06 3500 both have variable cam phasing. This necessitates an 
> advanced ECM. The latest engine that would be compatible with your current 
> (or any OBDI) ECM would be an '04-'05 3500. Stock 3400's have made over 
> 300 WHP turbocharged.
> MSD makes multi-channel boxes with adapters that mount between the DIS 
> module and the coils.
> Your page mentions an aftermarket datalogging system... what system is 
> that?
>
>
> Will
>
>
>> From: "David Allen" <davida1 at hiwaay.net>
>> Subject: Re: [Gmecm] Re: MSD or Delco DIS
>>
>>> BTW, im curious what type of vehicle this is in. Is is
>>> a s10 or camaro or an older front drive car ?
>>
>>   It'a an older FWD car - a Buick Century.  Maybe this didn't go through. 
>> http://home.hiwaay.net/~davida1/superc.htm shows the car and it has a 
>> link to the engine setup.
>>   I'm not in this for looks or to be able to say "I have an MSD ignition" 
>> to the riceboys.  I just wanted something that works properly with my 
>> setup.  A stock 1-coil distributor did NOT work properly... The MSD was a 
>> very non-invasive drop-in solution that absolutely _fixed_ the problem.
>>   The MSD box works exceptionally well, but my next motor will be a newer 
>> one with factory DIS. (maybe even a 3900!)
>>   I know the GN guys have a standard DIS and boost 20 PSI with it and 
>> have plenty of ignition.
>>   Thanks,
>> David
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 



From Robin at FuryWorld.fsnet.co.uk  Sun Dec 31 06:51:14 2006
From: Robin at FuryWorld.fsnet.co.uk (Robin Handley)
Date: Sun, 31 Dec 2006 12:51:14 -0000
Subject: [Gmecm] Re: MSD or Delco DIS
Message-ID: <014801c72cda$5e58d080$020101c0@gandalf>

> DIS is definately the way to go... but the
> rewards are worth it.

 Could I ask what you believe the benefits are? I had thought that there was
 no power advantage from DIS. I know that not having a dizzy saves rotor
 arm/cap wear and possible timing jitter.

 Robin



From Steve.Ravet at arm.com  Sun Dec 31 17:20:17 2006
From: Steve.Ravet at arm.com (Steve Ravet)
Date: Sun, 31 Dec 2006 17:20:17 -0600
Subject: [Gmecm] test, please read
Message-ID: <DBB2E4C4173F1749B6C74341406117830180FCAC@NASDAQ.usa.Arm.com>

It seems that the guy that hosts diy-efi.org let the domain expire and
someone else has taken it.  Not sure what the implications are but I
think the lists should still be working.  If you don't get this email,
then that means they aren't working.

--steve

-------------------
Steve Ravet
ARM
steve.ravet at arm.com


From wopontour at hotmail.com  Sun Dec 31 21:45:30 2006
From: wopontour at hotmail.com (WopOnTour)
Date: Sun, 31 Dec 2006 20:45:30 -0700
Subject: [Gmecm] Re: MSD or Delco DIS
References: <014801c72cda$5e58d080$020101c0@gandalf>
Message-ID: <BAY122-DAV6B948CBDC6AE96E2EB4D9BABB0@phx.gbl>

Some of the advantages are...
- less potential for cross-fire
- increased timing accuracy due to elimination of distributor gear drive 
system
-primary current (and thus delivered secondary energy) is generally higher 
than HEI
-longer dwell periods
-with 3 coils there's more recovery time
JMO
WOT
----- Original Message ----- 
From: "Robin Handley" <Robin at FuryWorld.fsnet.co.uk>
To: <gmecm at diy-efi.org>
Sent: Sunday, December 31, 2006 5:51 AM
Subject: Re: [Gmecm] Re: MSD or Delco DIS


>> DIS is definately the way to go... but the
>> rewards are worth it.
>
> Could I ask what you believe the benefits are? I had thought that there 
> was
> no power advantage from DIS. I know that not having a dizzy saves rotor
> arm/cap wear and possible timing jitter.
>
> Robin
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
> 



From william.lucke at highspeedlink.net  Sun Dec 31 12:32:02 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Sun, 31 Dec 2006 13:32:02 -0500
Subject: [Gmecm] Re: MSD or Delco DIS
Message-ID: <45980222.5060903@highspeedlink.net>

So you plan to build a controller external to the ECM that would handle 
the feedback loop to control the VVT actuator so that all the ECM would 
have to do is output a signal describing where it wanted the cam phasing 
held and wouldn't have to control the feedback loop itself. Interesting.



Will


> From: "David Allen" <davida1 at hiwaay.net>
> Subject: Re: [Gmecm] Re: Gmecm Digest, Vol 22, Issue 32
> 
>   I had planned to fully utilize the VVT - will be another challenge I look 
> forward to learning from.
>   Haven't taken it to the track because there are no tracks here that I know 
> of; and I'm not in the loop of people locally to make such an outing.  That 
> day will come however.
>   I'm using a Tech Edge 2B0 datalogger for this car.  Nothing high-tech; I 
> have to review the data in Excel and adjust the tables manually.
>   As for the VVT; I can build a controller which will look at cam reference 
> and crank reference and hold the VVT at whatever position is commanded. 
> This could take a duty-cycle signal from the ECM.  It could possible use the 
> PWM output, and table in the BIN originally for EGR to allow an older ECM to 
> work. Something to think about anyway.
>   I'd rather not have an MSD system unless it is necessary.  It was 
> necessary with the distributor but I bet DIS will be strong enough as-is.
>   Thanks!
> David
> 
> 
> 
> 
> - ---- Original Message ----- 
> From: "William Lucke" <william.lucke at highspeedlink.net>
> To: <gmecm at diy-efi.org>
> Sent: Saturday, December 30, 2006 6:59 PM
> Subject: [Gmecm] Re: Gmecm Digest, Vol 22, Issue 32
> 
> 
>> That's a cool setup. Have you ever taken it to a drag strip and gotten 
>> numbers?
>> The 3900 and '06 3500 both have variable cam phasing. This necessitates an 
>> advanced ECM. The latest engine that would be compatible with your current 
>> (or any OBDI) ECM would be an '04-'05 3500. Stock 3400's have made over 
>> 300 WHP turbocharged.
>> MSD makes multi-channel boxes with adapters that mount between the DIS 
>> module and the coils.
>> Your page mentions an aftermarket datalogging system... what system is 
>> that?
>>
>>
>> Will
>>
>>
>>> From: "David Allen" <davida1 at hiwaay.net>
>>> Subject: Re: [Gmecm] Re: MSD or Delco DIS
>>>
>>>> BTW, im curious what type of vehicle this is in. Is is
>>>> a s10 or camaro or an older front drive car ?
>>>   It'a an older FWD car - a Buick Century.  Maybe this didn't go through. 
>>> http://home.hiwaay.net/~davida1/superc.htm shows the car and it has a 
>>> link to the engine setup.
>>>   I'm not in this for looks or to be able to say "I have an MSD ignition" 
>>> to the riceboys.  I just wanted something that works properly with my 
>>> setup.  A stock 1-coil distributor did NOT work properly... The MSD was a 
>>> very non-invasive drop-in solution that absolutely _fixed_ the problem.
>>>   The MSD box works exceptionally well, but my next motor will be a newer 
>>> one with factory DIS. (maybe even a 3900!)
>>>   I know the GN guys have a standard DIS and boost 20 PSI with it and 
>>> have plenty of ignition.
>>>   Thanks,
>>> David


From william.lucke at highspeedlink.net  Sun Dec 31 12:38:01 2006
From: william.lucke at highspeedlink.net (William Lucke)
Date: Sun, 31 Dec 2006 13:38:01 -0500
Subject: [Gmecm] Schematic drawing program
Message-ID: <45980389.4000203@highspeedlink.net>

What would be a good (preferably free) program to draw 
schematics/circuit diagrams (not necessarily plan a board layout)?

Thx


Will