hey guys, im new here. I just bought a 1991 Camaro rs with the 3.1l. it has the check engine light on. I know how to read them but when I jump the two prongs n the diagnostic port, and turn the key to in, the check engine light blinks once. and then just stays on. what I do know about this car is the guy I bought it from put a 88 engine harness in it(the 91 had issues with it) and he changed the ecu I cant remember what he changed it to, but any ideas on y it wont pull codes would be a great help.

 

get the ECU number, IE 1227730???? so we will start there. you will need to verify wiring, don't worry we can walk you through it. just get the info so we can get you, and us the correct wiring info. to start with. I do have some experience with cross mated wiring/equiptment lol "my toy"

 

I took a picture of the ecu. not sure what numbers you would need

 

I ordered a new engine harness to replace the one he hacked in from the 88. so ill have that in about a week or so depending on shipping

 

smart move that will solve a lot of Search and destroy time LOL

1226870 that is what we needed

 

go here for pinout and voltage test values, looks like that is a 1985 only, so befor you get started we need to know the year of the wiring you ordered, so that you can get the right ECU. I do like your approach, start with a known good wiring harness. kudo's my friend

http://www.chevythunder.com/fuel%20i...nouts.htm#1985 pinouts (ecm #1226870)

 

PM sent.

 

So you have a 91 with a 88 harness and a 85 ECM ?

 

ya that is what I saw, that is why I suggested we wait until his wiring came in then find an ECM to match it, the EFI to body wiring is a walk in the park. but un bastardizing a wiring harness from long distance is ????? well, like trying to make love to a pi$$ed off panther, first off it aint gonna happen, second it aint gonna be as fun as it sounds.

 

Maybe the '870 is wired the same as a later V6 ECM but in the V8's
the '870 TPI ECM is a one year only wonder that requires many wiring mods for it to match up to a 86 - 89 TPI harness.

 

every time they designed a new ECU they would change the internal configuration, which will naturally change the external configuration also - go figure??? sorry I had to LOL. I do know for a fact that the '85 was the only year to have a burnoff relay. and it is unnessary to reprogram it when engine mods are made. air in air out that is about it. And every concurrent year emission laws changed.... later V6's used the same ECU ans the V8's with minor programming and wiring mods, GM learned that interchangability was more valuable in the long run


in short Loose the 870 unless you have an '85 "COMPLETE" system, wiring TPI, and ECU

 

any updates dude???

 

this guy must have bugged out on us????

 

sorry guys didn't bail on you. I work 2 fulltime jobs, very very busy. I get online when I can. I havnt had a chance to put the new harness on that I got

 

I ordered a harness for a 91, which is what the car is. my thought is if I can get the right harness and the right ecm for it MAYBE problems all solved. I think the guy I got it from was a hack dude anyways.

 

and what I have just read, I would need a 1227730 ecm for the 91 harness and motor?

 

just went out and looked at the extra ecm's he gave me, I have 2-- 1227730 ecm's one has a chip which is labeled aujx 0982. the other has no chip in it... ive done some research and found that that chip is the correct one for the computer. just not sure if there is an issue with these extra ecm's or not. any easy way to test them out of the car?

 

does it look like he cut the wiring up? if so pm me I may be able to assist. and yes that is the right ECU. there is a dude that will reflash your chip for $65 i believe, and turn off all of the "nonesentials"

 

What exactly are the non essentials? I know there's the V.A.T.S crap. oh while on that subject does the vats system keep the fuel pump from kicking on? just curious, he had a aux. switch for the starter and fuel pump. my guess was because of the vats system disabled it, am I on the right track with that thought? and I would love to have some one go through the chip and have there way with it. is it possible to do myself or is it pretty technical? I know my way mechanically around these cars but the electrical part im still learning

 

get ahold of a guy named " Tuned Performance " on here, he is Real good at what he does. I had him reflash a chip for me, and it works great.