I have been having idle troubles w/check engine light on, up and down idle, and high idle problems. One of the sensors are probably bad, but I heard a buzzing noise coming from the throddle body when I had the air cleaner lid off. Any help would be appreciated. BTW, I am refering to my 92 RS tbi.

 

IAC valve makes that sound wenn adjusting itself.

Could alredy read the error code, check fuel pressure and inspect the IAC valve.

 

I heard the buzzing sound after I removed the IAC and cleaned it with carb cleaner. I cleaned it, and arount the tb where it screws in. I am still having the idle issues though. up down up down idle, and sometimes it idles five hundred over where it should idle.

 

if its still buzzing, the IAC may still be getting stuck. Cleaning may help, but it won't save a worn out or dead unit.