Ok so from the beginning.I bought an 88 iroc with no engine or trans.I bought a used drivetrain from an 89 iroc.So the only difference is no cold start.Got everything together and running.Only problem is its very hard to start.Cranks strong but wont start.I have to crank it a little,shut it off,crank it a little,shut it off,etc....and i do this for like a minute until it finally starts.I was guessing because of no cold start.When it gets started it runs great....until it starts getting warm.The longer it runs,the worse it runs until after about 4-5 minutes its running like complete crap.It seems to develop a miss.And its at any RPM.I can hold it at 800 or 3000 and its the same.When i installed the engine i put in new plugs,wires,cap,rotor and module.I checked the timing and its dead on 6*.I checked fuel pressure key on engine off and its 43psi.Running its at 40psi.I did an injector balance test and all 8 injectors went from 43psi down to 30psi.Fuel pressure does not bleed off.I hooked a scan tool up and watched all the computer info.Everything seems to be within spec.I thought maybe was bad CTS but doesnt seem to be the case.Im thinking either the distributor or something fuel related.I did notice the reluctor wheel in the dist. was rusty.Any help would be great

 

Anyone?

 

I had the same issue. I replaced all of the injectors and the car is running great. It turned out I had two bad injectors. Hope this helps.

 

Are you using the Original 88 ECM or the 89 ECM that came from the transplant? They are completely different because of the cold start (9th Injector on the '88). The 89 ECM adds pulse width to enrich the cold start, the 88 does not. So an 88 ECM and an 89 non-cold start Injector engine are incompatable for that reason (maybe others as well). I do not know if the wiring pin outs are the same for 88 and 89, but there may be some really bad conflicts if you just plug in the 89 ECM to the 88 Harness.

 

I ordered new injectors from south bay injectors and a "piggy back" chip that now gives me the 89 cold start program.So this weekend ill be installing both and we'll see how i make out

 

Installed new injectors and chip and car runs great.Thanks for the help

 

GREAT! It is really good when a plan comes together. I knew that it had to be somehow related to the chip and cold start.