MacShamus

It's on a 1986, V8, Calif. Vin F, Chevy G20 Van. In 1998 the local dealer installed a 350/5.7 engine in it.

I've had this van for about six years. I never drove it much, it always started, but it needed an alternator. I put in a battery/alternator and rewired the starter. After that it had choke, acceleration and combustion problems.

It has a rebuilt, Rochester Quadrajet E4ME - 17085524 carburetor.
The ECM is labeled, re-manufactured, 1226865.

I found out how to read the EMC flash codes and I got an error message on the MAP sensor.

I have a voltmeter and just bought a hand held vacuum pump.

Now, what I need is the pinout diagram for this ECM and maybe some helpful info on how to test it. Other engine wiring diagrams would be a big plus.

Any advice will be welcome.

Thanks,
MacShamus

ECM 1226865 pinouts needed

Saar

i assume it came with a 5 liter?

here's the best diagram i can pull for it.

http://imgur.com/ZevSw.png

MacShamus

Saar,

Yes, it's a 3/4 ton and the VIN says it was a 5.0 liter V8 4BBL LF3.
I don't know if the ECM or harness was
changed out when the 350 cc engine was installed,
but some things must have been different.

Thanks,
MacShamus

Saar

i don't know enough about the old TBI setups to know an easy way to tell, but is there a 3 or 4 letter code on the PROM inside the ECM?

MacShamus

Well now, you got me there.
If TBI is an injection system, then this is not.
It has that E4ME Quadrajet with the MCS, TPS, and electric choke.

I know the Prom is a chip inside the ECM, and that's about all I know.

I have pinouts for three similar ECM's, including the one you sent. I'm comparing them for consensus.
Mac Shamus

Saar

even worse: i know next to nothing about the CCC systems!

they still used PROMs though, and there should be some kind of identifying marks on it to determine what the dealer did about it.

MacShamus

I took out the PROM and started to search codes, but...

DELCO
CE1090N
&
a small 8520 in a corner
1090 possible?

I think I can figure out the ECM from tracing wires colors in the harness. Don't need the exact diagram.

What if I'm trying to read a wire can I just ground some place other than in the terminal plug?

I need some general instructions on testing computer modules.

Shamus

Saar

ahh, the 8520 gives it away

the chip it has is intended for a 1986 G-van with a LF3 5.0V8 a 700R4 and california emissions...

MacShamus

OK
So that's the original ECM/PROM running the 5.7/350 engine.

Could I switch this engine from CCC top TBI?
Are there advantages?
What does it take?
New harness, new hardware?
Different ECM/PROM?

Shamus

MacShamus

Saar,
Thanks for all your time and attention.
I'll push on from here and let you know the
the repair.
Shamus