Identify This ECM

[george dailey]

At 10:52 PM 1/25/96 -0500, you wrote:
>
>   Does changing throttle body sizes have any effect on the calibration 
>of the unit?  

>   Since this box would be going on a Olds motor, and the original TPI 
>motor had a electronic distributor, would I be able to just hook the 
>newer distributor module to the Olds pickup (It's got a standard HEI in 
>it now) to get the right signals for the ECM?   Does the TPI distibutor 
>have a Hall Effect unit in it?
>
>> Peter Wales
>
>    Thanks guys... I got the replies before my message even showed up!
>
>                     -->   Bob Valentine  <--  
>                    --> ravalent at liii.com  <--

Pete or Bob (I've lost track),  the distributor connectors will interchange
if your olds an EST type HEI system.  There should be a 4 wire connector on
the olds distributor (7 term. HEI module).  Here's the magic,  I think the
tpi harness used the small HEI dist.  Your olds probably used the large HEI
dist.  Each system uses a 4 term connector. If the connectors don't match,
cut the car harness end and get another connector to match the olds dist.
The pin outs are as follows:

small dist
a	dist gnd
b	bypass
c	reference
d	est

large dist
a	est
b	reference
c	bypass
d	gnd

I'm not sure that there is any electronic difference between the two units.
If there is, My chopped, dropped, and swift TBI '58 chevy doesn't care. It's
been running strong for about a year with no problems.  I later found a book
that confirmed this so don't let the text book gurus rattle you.  It sounds
like you are going to drill the olds manifold for port injectors.  If  this
is the case, I would recommend using the MAF sensor.  Yes, it will increase
the complexity of the wiring, but it uses the true mass air flow to
calculate injection duration.  Modifiers and racers alike love this method
because it is very forgiving to cam, exhaust and induction system changes.
Changing from an tuned port arrangement to something else is hairy if the
electronics is still using manifold absolute pressure (and associated look
up tables) to calculate the injection duration.

Don't let this deter you,  the system still might work Reasonably well.
Most modifiers who have tried it say, a custom prom will be needed. 

Roll the dice buddy! Or keep on asking the right questions.

>
>George M Dailey gmd at tecinfo.com
>