Need Help with 90 Coupe

[my90c4]

This problem started after I had the intake manifold resealed as I had a serious fluid leak. Idles rough and stumbles while running, ECM shows a code 42. Suggested that ignition module or ECM be replaced. Could this be a vacuum problem or spark plug wires ? At a lost need help, please! Only have owned Coupe for a year and only has 25,000 miles on it.

Thanks in advance for all your help.
my90c4

 

[vetteboy86]

I know after my bro had his engine rebuilt it ran like crap as you are describing. They tracked down the vacum leak. I would say that it probably is the culprit in your case. I also hope that is the problem. Good luck and let us know what you find.

Craig

 

[Hrtbeat1]

Your on the right track

Mine had a similar happening about a year after I got it. I'm not sure if it was the Ignintion Module or the ECM. I replaced both plus the distributor wiring terminal as it broke where the hold down screw was. The '90 uses the seven pin Module and I think I got the ECM from Autozone. Haven't had a problem since.