Just took out my IAC to clean and the plunger is very stiff. It seems like it should move freely in order to sense flow. Am I wrong? Does anyone have the GM part number for it (91 Camaro 5.0 TPI). Thanks.

 

Yes, you are incorrect. The plunger doesn't "sense" anything, it is a threaded shaft that is turned by the IAC motor which adjusts its position. When you pull or push on the plunger you are "jumping" the teeth or threads that are on the shaft of the plunger and it should be pretty stiff.

 

Thanks