Hello everyone, first time poster.
I have a 1991 Z28 that is idling rough. Seems to be idling too rich, I'm guessing it is a sensor? Runs just fine running down the road. Not much of a mechanic myself, know just enough to get myself in trouble. Any suggestions? By the way I've had this car since it was new, 65k mi. now.
Cary

 

If the SES lite is lit, get the ECM scanned or try to pull the codes.

 

No lights are on.
Cary

 

And how many tune ups have you done on the car since it was new? Done one lately?

 

Idling rough while cold? Or, idling rough during all power bands. Meaning, does it only idle rough while cold or does it also idle roughafter the engine warms up? Have you replaced the spark plugs and injectors lately? You'll be amazed with the difference these two adjustments make on your 3rd gen. Not to patronize but, be sure to install the spark plugs with the correct gap.