I own 89 iroc 5.7 that recentlly started to hunt for idle, idles rough but doesnt stall. The car actually runs really good when on the street. The following have been recently installed cap, rotor, plugs, iac, battery, coolant temp sensor, starter, and starter remote selenoid.

When cold the car idles good with only a hint of idle hunt. Once, the car warms up the idle begins to hunt from 500 to 700 rpms. It started to hunt for idle after I used throttle body cleaner on the tb and iac hole.

Car is not throwing any codes, what could be wrong? Any help is appreciated

 

Maybe a vacuum leak?

 

Thanks for the reply camaronewbie. I found a vacuum leak at the t connection leading into vacuum reservoir. That did change the idle hunt. I disconnected maf and the car ran smoother with a slight idle hunt. Could that be it? The check engine light only lights because of mas being disconnected. I'm getting frustrated, I need help.

 

No expert on MAF stuff here so can't help any further - but any car can "hunt" for an idle with a vacuum leak and so I thought I'd throw it out there.