I know enough to be an idiot but that's mainly with the 1987 IROC I have. I bought this 91 1LE. It's super clean but runs likes crap. Here's the story. PO had the ECM replaced. I haven't looked at it yet but he says it was done by a GM specific shop so for now I'm assuming they put in the proper ECM. (But you know what they say about assuming.)Occasionally it takes more cranks then it should to cold start but it always starts cold. It seems to run well for about 20 minutes or until the temp hits about 210-220. Then the idle wanders, runs crappy and has even died on me on the freeway under heavy acceleration. At this point it won't hot start again at all and it smells flooded. So far all I have done is replace the ICM and pulled the following two codes. 32 for EGR and 44 for O2 sensor indicating lean.

Replacing an EGR is no fun but an O2 is easy and I have one new one so that will get done next couple days. But riddle me this. If the O2 sensor says lean then why does it smell heavily of gas when hot? Does the lean reading cause the ECM to dump extra gas in?

My research here also indicates that it could be the coils in the injectors or the electronic spark control. BTW; side question, is the ESC really integral to the ECM on 91 and 92? Its on the firewall in 87.

Anybody have any other ideas?

And lastly, When I get his car and my two 87's running decent I want to have them tuned. Any good tuners in northern CA you can suggest?

Thank All

 

Well I guess I will work on my own solution. I've tested and debugged virtually everything expect for one that I can think of. So now I test the injectors. As far as I can tell these are the original MulTec injectors and everybody says they are crap. So I ohm test them just now and I get readings on 3 of them under 8 ohms, 2 are between 8 and 12 and the other 3 are above 15. That is obviously not within spec. So I've sent an email to SouthBay to confirm my suspicion that the problem is the injectors. I've read that this can certainly cause long cranks times, hard cold start and not start at all after they get warm. I'm almost certainly going to be ordering new injectors tomorrow.

 

Sounds similar to the situation I had with mine. Cold it ran great, warm I almost didn't get home. Although I replaced the ignition module on mine new injectors solved the problem. I got mine from SouthBay.