injector duty cycles
Todd King
Todd_King at ccm.co.intel.com
Wed Dec 4 22:20:11 GMT 1996
File item:
24248
DIY_EFI Digest Wednesday, 4 December 1996 Volume 01 : Number 369
In this issue:
Re: DIYEFI FAQ
Nissan ECCS
Re: needhams emp-20 device programmer
Re: Injector Connectors
Re: Schematic of a GM ALDL -> PC converter
Re: Schematic of a GM ALDL -> PC converter
Re: Schematic of a GM ALDL -> PC converter
Re: crankshaft/flywheel encoder patterns
Re: Injector Connectors
Re: crankshaft/flywheel encoder patterns
Turbo City ?
Re: Injector Connectors
Re: Schematic of a GM ALDL -> PC converter
Re: needhams emp-20 device programmer
test
Test
Limits of TPI computer
Re: Turbo City ?
re: Limits of TPI computer
Re: Limits of TPI computer
Re: Nissan ECCS
Re: Schematic of a GM ALDL -> PC converter
See the end of the digest for information on subscribing to the
DIY_EFI or DIY_EFI-Digest mailing lists.
----------------------------------------------------------------------
From: "Joachim Glasstetter" <glassjo at vs-ulm.dasa.de>
Date: Tue, 3 Dec 1996 11:07:37 -0100
Subject: Re: DIYEFI FAQ
Wow, the FAQ is a very good idea, but somebody has to put togehter the
material.... ;-), somebody with too much freetime :-)
I would be able to write down a 'which efi in which german car' -list.
hope we will find somebody...
Joachim
===================================================
Dipl.-Ing. Joachim Glasstetter
VS2E22
Daimler-Benz Aerospace AG
Woerthstrasse 85
89077 Ulm
Germany
http://www.geocities.com/MotorCity/1642
Tel. +49 731 392 4731 '70 VW Beetle
Fax. +49 731 392 4958 '83 VW POLO GT
'85 VW Beetle
===================================================
------------------------------
From: Mike Jankowski <mike at bimberi.com.au>
Date: Tue, 03 Dec 1996 22:31:03 +1100
Subject: Nissan ECCS
Hi
I own a 1989 Nissan Skyline with a RB30E 6 Cyl engine using the Nissan ECCS
EFI.
Does anyone have any experiences in modifying this system for increased
performance?
Thanks
Bimberi Systems /\ Networking and High Avalability mike at bimberi.com.au
_______________/ \ Unix Specialists http://www.bimberi.com.au
PH: +61 419 492 646 FAX: +61 6 291 4818
------------------------------
From: Tim Drury <tim.drury at gtri.gatech.edu>
Date: Tue, 3 Dec 1996 07:42:02 -0500
Subject: Re: needhams emp-20 device programmer
>Should have come w/ 3 cards to do all 8 and 16 bit 27xxx,28xxx parts.
And the third "family module" does PALs and GALs.
- -tim
------------------------------
From: "Curt Martin" <cmartin at america.com>
Date: Tue, 3 Dec 1996 08:56:07 -0500
Subject: Re: Injector Connectors
> Hi All
>
> Need to find a good source for the connectors that plug into injectors on
a
> GM TPI unit. Have been scrounging the local u-pull-it, nothing left. Got
> the rest of harness parts - will start building soon.
>
> Thanks Vance
Vance.... broaden your junkyard search parameters.... *ANY* multiport
injected GM car will have the connectors you seek (Cavilers, Celebrities,
V6 Camaro's, V6 Fiero's, Grand Ams,... you get the picture) The connector
is a standard item (If I'm not mistaken, Ford and some imports use the same
connector too.)
Curt Martin (cmartin at america.com)
Ormond Beach, Florida
http://www.america.com/~cmartin/
------------------------------
From: Mark Bjork <snomo at ballcom.com>
Date: Mon, 02 Dec 1996 14:15:48 -0800
Subject: Re: Schematic of a GM ALDL -> PC converter
Michael F. Sargent wrote:
>
> I have no idea. :-)
>
> The level shifting from ALDL levels to RS-232 must be the problem. Async
> communications is very forgiving of clock speed mismatches. It has to be.
>
> Mike
>
> ----------
> From: owner-diy_efi at coulomb.eng.ohio-state.edu on behalf of John Faubion
> Sent: Thursday, November 28, 1996 9:49 AM
> To: diy_efi at coulomb.eng.ohio-state.edu
> Subject: Re: Schematic of a GM ALDL -> PC converter
>
> > Why bother?
> >
> > Serial I/O is designed to be able to handle at least a 5% error in clock
> rates
> > between sender and receiver. Using 8228 instead of 8192 is less than 0.5%
>
> > error.
>
> Mike if this works then why are there not more people doing this? The
> software should be easy and the cable should be easier. Additionally if its
> that easy, why did Diacom spend the time to write software to adapt to a
> parallel port? 8{)
>
> John Faubion
> jfaubion at beaches.netThe spec for RS232 is (i believe) a logic 1
for any signal below .2v, and
a logic 0 for any voltage above 2.7v. Therefore, even though RS 232 is
meant to be -15 and +15, the ALDL signal of 0v (logic 0) and 5v (logic 1)
will work if the signal is "inverted".
I am not a comm port expert, but from recently checking some serial
interface databooks, i belive the above is true.
Mark
------------------------------
From: Mark Bjork <snomo at ballcom.com>
Date: Mon, 02 Dec 1996 14:09:49 -0800
Subject: Re: Schematic of a GM ALDL -> PC converter
John Faubion wrote:
>
> > Why bother?
> >
> > Serial I/O is designed to be able to handle at least a 5% error in clock
> rates
> > between sender and receiver. Using 8228 instead of 8192 is less than 0.5%
>
> > error.
>
> Mike if this works then why are there not more people doing this? The
> software should be easy and the cable should be easier. Additionally if its
> that easy, why did Diacom spend the time to write software to adapt to a
> parallel port? 8{)
>
> John Faubion
> jfaubion at beaches.netBecause, if they didn't use a harware "hardkey"
then all one would have
to do is copy the software and pass it on the the next guy.
Mark
------------------------------
From: Mark Bjork <snomo at ballcom.com>
Date: Mon, 02 Dec 1996 14:02:43 -0800
Subject: Re: Schematic of a GM ALDL -> PC converter
John Faubion wrote:
>
> > You can't program a PC UART to 8192 baud, but
> >you can program it to 8228 using a divisor of 14, which is close enough.
>
> Actually why not change the XTAL to a 3.2768Mhz and use a divisor of 25?
> With the UART's internal divisor of 16 and a programmable divisor of 25
> would get 8192. Plus this is a standard crystal which costs about a dollar.
> Dual port serial cards for the PC are around seven dollars now. Looks like
> a cheap way to talk to it. Or I guess someone with a bit more EE skills
> could probably whip up a circuit for it using that crystal, a UART, a
> couple IC's and a few discretes to connect to a parallel port. Anyone with
> the know how for this willing to take a shot. I'm willing to build it.
>
> John Faubion
> jfaubion at beaches.netThe only hardware you need is a ciruit to "invert"
the data. Other than
that you can ( as someone mentioned earlier in this thread) do the rest
in software. We (a friend and I) did connect a pc to the ALDL port over
the weekend, and did obtain data from the port, but, we hadn't "borrowed"
any hardware from work to do the inverting. Tonight, we hope to have a
simple serial communication inverter circuit ready. Then we should be
able to get valid data. The data we obtianed would be correct if we did a
BSL on each word (I think that would work) but since the "level" of the
start bit was inverted, the data is tough to decipher. I will post the
results of our "test" as soon as we have something further.
Mark
------------------------------
From: Mark Eidson <mark.eidson at tempe.vlsi.com>
Date: Tue, 3 Dec 1996 08:32:51 -0700
Subject: Re: crankshaft/flywheel encoder patterns
This is the same approach I have come up with but I'm only in the thought
process. Are you going to sequence your counters so that each cylinder will
have a programmable injection timing? This will also work for ignition. I
thought a phase locked loop running at a higher frequency would give more
accuracy than 1 degree of cam rotation but can't figure out an easy to get
the dynamic range required. me
***************************************************************************
* Mark Eidson Voice: (602)752-6513 *
* Staff Design Engineer Fax: (602)752-6000 *
* Manager System Integration and *
* Verification E-Mail: mark.eidson at tempe.vlsi.com *
* VLSI Technology, Inc. *
* 8375 South River Parkway *
* M/S 265 *
* Tempe, Arizona 85284 *
***************************************************************************
------------------------------
From: kleenair at ix.netcom.com
Date: Tue, 03 Dec 1996 10:35:53 -0800
Subject: Re: Injector Connectors
Curt Martin wrote:
>
> > Hi All
> >
> > Need to find a good source for the connectors that plug into injectors on
> a
> > GM TPI unit. Have been scrounging the local u-pull-it, nothing left. Got
> > the rest of harness parts - will start building soon.
> >
> > Thanks Vance
>
> Vance.... broaden your junkyard search parameters.... *ANY* multiport
> injected GM car will have the connectors you seek (Cavilers, Celebrities,
> V6 Camaro's, V6 Fiero's, Grand Ams,... you get the picture) The connector
> is a standard item (If I'm not mistaken, Ford and some imports use the same
> connector too.)
>
> Curt Martin (cmartin at america.com)
> Ormond Beach, Florida
> http://www.america.com/~cmartin/You are not mistaken. Ford, Chrysler
and other port injection connectors
will fit.
Best Regards,
Mazda
------------------------------
From: kleenair at ix.netcom.com
Date: Tue, 03 Dec 1996 10:56:53 -0800
Subject: Re: crankshaft/flywheel encoder patterns
Mark Eidson wrote:
>
> This is the same approach I have come up with but I'm only in the thought
> process. Are you going to sequence your counters so that each cylinder will
> have a programmable injection timing? This will also work for ignition. I
> thought a phase locked loop running at a higher frequency would give more
> accuracy than 1 degree of cam rotation but can't figure out an easy to get
> the dynamic range required. me
> ***************************************************************************
> * Mark Eidson Voice: (602)752-6513 *
> * Staff Design Engineer Fax: (602)752-6000
Hi Mark,
Yes, I plan to sequence them, and I'm using the same approach for
ignition coils. Also, with one edge per crank degree, we can narrow our
resolution to 0.5 degrees of cam rotation not 1 degree, and for my
purposes this is accurate. I know there are systems out there that claim
they are more accurate, but I don't know beyound 1/2 degree if it makes a
difference.
The reason I decided to go this route was to relieve the processor from
too many interrupts. I plan to set the processor up to be interrupted on
every rising edge of the crank sensor (once every 2 degrees of crank
rot). When there is a rising edge on the CAM, I'll set angle to zero,
and increment by two on every crank interrupt. I then reload the
counters (by writing to a memory location), when their proper angle comes
up.
I'd like to discuss this more, but I'm out of time right now. Write me
back on what you think.
------------------------------
From: Jack Alford <jalford at off-road.com>
Date: Tue, 3 Dec 1996 10:53:49 -0600
Subject: Turbo City ?
Anybody know if Turbo City is still in business, I remember reading an
article about them using a pair of 2.5L TBI units in some magazine a
while back. I just tried to call their number in an old magazine I have
and I get the 'they don't live here any more" message ???????
- jack
------------------------------
From: peter paul fenske <pfenske at direct.ca>
Date: Tue, 3 Dec 1996 09:46:56 -0800
Subject: Re: Injector Connectors
At 06:35 PM 12/2/96 -0800, you wrote:
>Hi All
>
>
>Need to find a good source for the connectors that plug into injectors on a
>GM TPI unit. Have been scrounging the local u-pull-it, nothing left. Got
>the rest of harness parts - will start building soon.
>
>Thanks Vance
>
Hi Vance
I'll look in the GM Y body parts book for you. Gm does make new
ones.
Later: peter
------------------------------
From: Stephen Dubovsky <dubovsky at vt.edu>
Date: Tue, 3 Dec 1996 13:39:05 -0500
Subject: Re: Schematic of a GM ALDL -> PC converter
...
>The spec for RS232 is (i believe) a logic 1 for any signal below .2v, and
>a logic 0 for any voltage above 2.7v. Therefore, even though RS 232 is
>meant to be -15 and +15, the ALDL signal of 0v (logic 0) and 5v (logic 1)
>will work if the signal is "inverted".
...
Used to be that -5 to +5 (or +-7) was invalid for RS232 inputs back when
everyboy went from -12 to +12. (The invalid area was a hysteresis band so
you HAD to cross both boundries to toggle the bit) Now with all the 3.3V
chips around, they use a charge pump to get almost +6.6V and -6.6 (usually
+6.2 and -6.0 in my exp) and the hysteresis band is reduced to something
like +-2V. I believe it is still bipolar, so if you only go from 0V to 5V
the bit may get 'stuck' in one direction. Hope this helps... You might
also have a serial interface that doesn't truly follow the RS232 spec and
toggles around 0.7-2.7V though.
SMD
- --
Stephen Dubovsky
dubovsky at vt.edu
95 Yamaha FZR600
83 Porsche 911SC
84 Jeep Cherokee
------------------------------
From: ashok bala <ashok at belaray.com>
Date: Tue, 03 Dec 1996 10:41:49 -0800
Subject: Re: needhams emp-20 device programmer
Sorry my mistake...
my programmer was not working properly, which is why I was unable to use
the 01A module to program EPROMS.... I have contacted needhams and they
are fixing the problem..
Tim Drury wrote:
>
> >Should have come w/ 3 cards to do all 8 and 16 bit 27xxx,28xxx parts.
>
> And the third "family module" does PALs and GALs.
>
> -tim
------------------------------
From: Jussi T Kosonen <jkosone1 at cc.hut.fi>
Date: Tue, 3 Dec 1996 21:50:06 +0200 (EET)
Subject: test
Test
------------------------------
From: Jussi T Kosonen <jkosone1 at cc.hut.fi>
Date: Tue, 3 Dec 1996 21:46:11 +0200 (EET)
Subject: Test
only a test
------------------------------
From: Jussi T Kosonen <jkosone1 at cc.hut.fi>
Date: Tue, 3 Dec 1996 22:54:13 +0200 (EET)
Subject: Limits of TPI computer
Hi you all!!!
I have few questions about stock TPI computer limitations.
I own a -85 Vette (MAF computer) with quite heavy modifications that
include....
-400 cid block bored 0.03"
-stroker crank 3.875"
= 420 cid
-Dart II Sportsman cylinder heads
-Compucam 2040 cam duration @ .050"=210/216 gross lift=.440"/.454"
-SLP T-Ram manifold
-Accel 58mm throttle body
-Hedman Hedders with 1 5/8" tubes 3" collectors
-Dual 2 1/2" exhaust tubing no catalytic converter
-3" Flowmaster mufflers
-modified MAF and air filter housing
with STOCK computer,fuel pump, injectors 24lbs/hr, fuel filter.
And that is what worries me ......
Is the stock TPI computer able to operate my engine??
I know that computer with MAF is quite tolerable with engine modifications
but still I fear that I'am not using the full potential of my engine.
I have the TPIS Insider Hints book that states that stock injectors
are able to produce +450 HP and they also say that it is better to
use small injectors with high fuel pressure than bigger ones with
lower.
I don't know how much HP my engine is producing but taking in a account
that my cam is so mild I estimate less than 450HP...
but that book doesn't tell me what pressure should use.....
currently I have set it to 45PSI....
The question is......could I damage my engine at high RMP with
too lean mixture..?
Any advise appreciated!!!!
Jussi
------------------------------
From: Todd Knighton <knighton at net-quest.com>
Date: Tue, 03 Dec 1996 14:06:32 -0800
Subject: Re: Turbo City ?
Jack Alford wrote:
>
> Anybody know if Turbo City is still in business, I remember reading an
> article about them using a pair of 2.5L TBI units in some magazine a
> while back. I just tried to call their number in an old magazine I have
> and I get the 'they don't live here any more" message ???????
>
> - jack
Yup, they're at (714) 639 4933 as of a July 1996 Turbo mag.
1137 W. Katella Ave., Dept. TRB, Orange, CA 92667
Todd Knighton
Protomotive Engineering
------------------------------
From: SRavet at bangate.compaq.com
Date: Tue, 3 Dec 96 16:07:40 CST
Subject: re: Limits of TPI computer
Jussi T Kosonen <jkosone1 at cc.hut.fi> Wrote:
|
|
| Hi you all!!!
| I have few questions about stock TPI computer limitations.
|
| I own a -85 Vette (MAF computer) with quite heavy modifications that
| include....
|
| -400 cid block bored 0.03"
| -stroker crank 3.875"
| = 420 cid
| -Dart II Sportsman cylinder heads
| -Compucam 2040 cam duration @ .050"=210/216 gross
lift=.440"/.454"
| -SLP T-Ram manifold
| -Accel 58mm throttle body
| -Hedman Hedders with 1 5/8" tubes 3" collectors
| -Dual 2 1/2" exhaust tubing no catalytic converter
| -3" Flowmaster mufflers
| -modified MAF and air filter housing
|
| with STOCK computer,fuel pump, injectors 24lbs/hr, fuel filter.
|
| And that is what worries me ......
|
| Is the stock TPI computer able to operate my engine??
| I know that computer with MAF is quite tolerable with engine
modifications
| but still I fear that I'am not using the full potential of my engine.
|
| I have the TPIS Insider Hints book that states that stock injectors
| are able to produce +450 HP and they also say that it is better to
| use small injectors with high fuel pressure than bigger ones with
| lower.
|
| I don't know how much HP my engine is producing but taking in a account
| that my cam is so mild I estimate less than 450HP...
| but that book doesn't tell me what pressure should use.....
| currently I have set it to 45PSI....
|
| The question is......could I damage my engine at high RMP with
| too lean mixture..?
Yes you could, but you would probably see a "Block Learn" error first.
Block learn is what allows the ECM to "lean" a new fuel curve for your
engine. It is a modifier that is added/subtracted to the base injector
timing stored in the table. It can only be adjusted so far, though, and if
the computer can't increase it any further and it still sees lean operation
then it will set a "block learn out of range" error. This won't help WOT
much, since feedback is not used then. Your best bet would be to hook a
high impedance multimeter to the O2 sensor and have someone watch it while
you drive to see if you are rich/lean. If you are lean at WOT, you should
probably create more fuel flow by increasing the pressure or getting bigger
injectors. The block lean will take care of adjusting part throttle
conditions, and the larger injectors will increase fuelling at WOT. If you
get a scan tool or Diacom software, you can see the block learn values, O2
sensor values, etc. all as you drive around.
What's your 1/4 mile time?
- --steve
Steve Ravet
sravet at bangate.compaq.com
Baby you're a genius when it comes to cooking up some chili sauce...
------------------------------
From: Mazda Ebrahimi <kleenair at ix.netcom.com>
Date: Tue, 03 Dec 1996 19:07:39 -0500
Subject: Re: Limits of TPI computer
Jussi T Kosonen wrote:
> I have the TPIS Insider Hints book that states that stock injectors
> are able to produce +450 HP and they also say that it is better to
> use small injectors with high fuel pressure than bigger ones with
> lower.
I don't know the specifics of the TPI, but this advice is good for two
reasons. One is that you generally get better atomization of fuel with
higher pressure. The second is that going to larger injectors may
negatively affect your idle.
>
> I don't know how much HP my engine is producing but taking in a account
> that my cam is so mild I estimate less than 450HP...
> but that book doesn't tell me what pressure should use.....
> currently I have set it to 45PSI....
>
> The question is......could I damage my engine at high RMP with
> too lean mixture..?
It's possible. But if it happens, it will happen right near stoich. at
wide open throttle (this is the hottest combustion you can get). The
best way to find out is to monitor your O2 sensor as suggested by
someone else.
There are a couple of other things that may be interesting to check.
One is your fuel pressure at maximum power, to make sure your fuel pump
is keeping up with the demand. When this is the case, you can usually
tell even by driving the car.
The other is your injector duty cycle. Generally, you would like to
keep the maximum injector duty cycle at or below 80% (I think it keeps
the injector driver chips from overheating, but I'm not sure). I wonder
if the ECM will exceed this number if fuel flow demands require it to?
Hopefully someone else on the mailing list has an answer.
Best Regards,
Mazda
------------------------------
From: MaxBoost at aol.com
Date: Tue, 3 Dec 1996 20:00:30 -0500
Subject: Re: Nissan ECCS
>Does anyone know who can program Nissan ECCS systems......snip
Call Clark at Jim Wolf Technology in El Cajon, 619-433-0680. They have years
of experience with the ECCS system. They have done the ecu for a couple of
my cars and I trust their work.
Max.
------------------------------
From: Darrell Norquay <dnorquay at iul-ccs.com>
Date: Wed, 4 Dec 1996 05:34:05 GMT
Subject: Re: Schematic of a GM ALDL -> PC converter
At 01:39 PM 12/3/96 -0500, SMD wrote:
>Used to be that -5 to +5 (or +-7) was invalid for RS232 inputs back when
>everyboy went from -12 to +12. (The invalid area was a hysteresis band so
>you HAD to cross both boundries to toggle the bit) Now with all the 3.3V
>chips around, they use a charge pump to get almost +6.6V and -6.6 (usually
>+6.2 and -6.0 in my exp) and the hysteresis band is reduced to something
>like +-2V. I believe it is still bipolar, so if you only go from 0V to 5V
>the bit may get 'stuck' in one direction. Hope this helps... You might
>also have a serial interface that doesn't truly follow the RS232 spec and
>toggles around 0.7-2.7V though.
The true RS232C standard specifies +/- 15 volt signals. This was sortof
relaxed to +/- 12 volts when personal computers started becoming popular.
The signal was supposed to have a "dead band" between +/- 3 volts, which
allowed for lots of signal loss over long wires. There is actually another
standard, (I forget the RS number), which is a modified RS232 that only
swings +/- 5V. This was (and is) used a lot on laptops, etc. It was still
called an RS232 port, however, (even though it's not) because if your cables
weren't too long, it would still talk to a true RS232C input. I don't think
this will work with a single-ended 0-5v signal, since it must swing
significantly negative to get it to change from space to mark.
Any of the "backwards" converters using a MAX232 presented here recently
should work nicely, though. Since "mark" is negative, and "space" is
positive, an additional inverter may be required to get the proper
signal into the serial port of a PC.
regards
dn
dnorquay at iul-ccs.com
------------------------------
End of DIY_EFI Digest V1 #369
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Text item: External Message Header
<<<
The other is your injector duty cycle. Generally, you would like to
keep the maximum injector duty cycle at or below 80% (I think it keeps
the injector driver chips from overheating, but I'm not sure). I wonder
if the ECM will exceed this number if fuel flow demands require it to?
Hopefully someone else on the mailing list has an answer.
Best Regards,
Mazda
>>>
I find that at WOT my injectors go greater than 99% duty cycle for most of the
time. The ECM is a GM SFI unit (Buick Grand National). This high duty cycle is
common at WOT. The ECM does send out a token closing "blip" that keeps things in
true SFI mode; essentially the injectors are just serving as holes in the fuel
rail at WOT.
Todd Todd_King at ccm.co.intel.com
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