Hey guys I need your help. Today I was leaving my girlfriends and I went to start my car ( 1991 formula firebird, 5.7l FI 350) and it was idling between 1500 - 2k rpm's. It was bouncing quite profusely between them. On top of that it was " jumping " quite bad if I put it into drive. Any ideas what it could be?

 

Check your Idle Air Control (IAC) sensor. It is located on the bottom, passenger side of the throttle body.

In my experience, they can get a carbon buildup resulting in the spring/pintle becoming compressed instead of "springy". This throws off the air reading to the computer.

Hope this helps!

 

Thanks, I cleaned it out today and its not idling high anymore just jumping a bit when im braking for a while, is this a sign of it going bad and i need to replace it?