[Gmecm] Chevy 350 Carburated to TBI / TPI?

Fri Jan 12 03:49:57 UTC 2007

Not to sound ignorant, however much I may be on the topic, what exactly 
is a CAL?

Jake Tucker wrote:
> Bob,
>     If you are going to use a TH400 transmission, you will want to find
> a wiring harness from a truck equipped with the TH400 and use a CAL from
> a TH400.  If you can't find the CAL, let me know and I can tell you
> which one I used that I uploaded to the server several years ago.  The
> TH400 uses an electric solenoid for the kick-down on the transmission.
> On a carb, this is activated by a simple switch that is below the gas
> pedal and senses full throttle.  On a TBI system, it is controlled by
> the computer, which allows you to change the set point.  You can
> probably re-pin a harness that doesn't have this wire, but that's a
> little more difficult.  Look for an orange wire that is by itself, near
> the firewall on the drivers side.  The TH350 and manual trans versions
> of the TBI system will not have this wire.  The TH350 uses a mechanical
> cable for the kickdown, and obviously the manual trans doesn't do
> anything.
>
> Jake
>
> -----Original Message-----
> From: gmecm-bounces at diy-efi.org [mailto:gmecm-bounces at diy-efi.org] On
> Behalf Of Aphelion79
> Sent: Thursday, January 11, 2007 4:13 PM
> To: gmecm at diy-efi.org
> Subject: Re: [Gmecm] Chevy 350 Carburated to TBI / TPI?
>
> Ok, so that means I will need the distributor from the truck that I pull
>
> the TBI, harness, and ECM out of (and all accompanying sensors) as well 
> right?
>
> Also one more thing I've thought of...
> How does the TH400 transmission work with the stock carburetor?  Does it
>
> have anything to do with it? If so, how does this work with the TBI?  
> I've only messed with manual transmissions in my lifetime, never worried
>
> about autos! =)
>
> Thanks for all the help, thats about all I can think of that I'd have 
> problems/concerns about!
>
> Jay Vessels wrote:
>   
>> Hi there!
>>
>>     
>>> I was wondering if the TBI systems used on the '87+ Truck 350s were 
>>> fuel only, or did they control timing as well?
>>>       
>> They controlled the timing as well, through the distributor ignition 
>> module.
>>
>>     
>>> On the GM 151 4cyls I've had experience with they used a computer 
>>> controlled timing curve (basically the same idea as a vacuum advance,
>>>       
>
>   
>>> I.E. the computer has NO idea where the timing is in relation to the 
>>> crankshaft)
>>>       
>> The ECM doesn't have absolute position of the crank, but it does have 
>> relative position in that it trusts that the distributor is set at a 
>> particular static timing position, and it adjusts from that.  Since it
>>     
>
>   
>> is not doing individual cylinder timing adjustments and is not doing 
>> sequential fuel injector firing it does not need to know exactly where
>>     
>
>   
>> the crank is.
>>
>>   I also know of other types of engines using complete timing
>>     
>>> control where the use of a crankshaft positioning sensor / knock 
>>> sensor is used...
>>>       
>> Many GM DIS systems don't provide crank position to the ECM.  The 
>> ignition module has that data but doesn't pass it on since the ECM 
>> doesn't need it.
>>
>>     
>>> Also, for an O2 sensor, do you need one for each "side" of the 
>>> engine? (Where as my previous knowledge is I4 and I6's, I only have 
>>> one exhaust manifold! =D )
>>>       
>> For this system (older TBI) there is only one sensor.
>>
>>     
>>> Also these systems are all OBDI, because to my knowledge OBDII didn't
>>>       
>
>   
>>> start up until 1996?  (Dunno where I got that year from, but for some
>>>       
>
>   
>>> reason it comes to mind, lol.)
>>>       
>> Right on both counts.
>>
>> Jay Vessels
>> 1982 Chevrolet S-10 Sport, 2.8V6 TBI
>> 1984 Chevrolet S-10 Blazer Sport, 2.8V6 (TBI pending)
>>
>>
>>     
>>> Thanks for the support everyone!
>>>
>>> Jake Tucker wrote:
>>>       
>>>> Bob,
>>>>     The Carter is a square bore, just like a Holley.  As a matter of
>>>> fact, I believe the only stock spread bore carb was a quadrajet
>>>> (although that was almost all GM 4 barrel carbs).  Holley, and
>>>>         
> others,
>   
>>>> do make a spread bore replacement, but the OEM carbs that weren't
>>>> quadrajets were all square bores.
>>>>
>>>> Jake
>>>>
>>>> -----Original Message-----
>>>> From: gmecm-bounces at diy-efi.org [mailto:gmecm-bounces at diy-efi.org]
>>>>         
> On
>   
>>>> Behalf Of BNRVL at aol.com
>>>> Sent: Tuesday, January 09, 2007 11:45 AM
>>>> To: gmecm at diy-efi.org
>>>> Subject: Re: [Gmecm] Chevy 350 Carburated to TBI / TPI?
>>>>
>>>>
>>>>
>>>>  Hello , what is the bolt pattern for  69 Corvette Carter carb.  ??
>>>>
>>>>  thanks
>>>>  Bob Norville
>>>>         
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>>     
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