I've been trying to find the problem to my little misfire/ high idle on my 97 tahoe for a LONG LONG time now... I tried cleaning my IAC the best I could few days back. I couldn't take it totally out of the Throttle Body due to one of the bolts being stripped. I get it all back together, start it, idle was way lower. Shut it off, start it back up, idle went sky rocket like normal which is in the 1800-1900 RMP range, and then it drops down to 1400, and once in gear it goes to about 900. I take it out of town later that night, it starts chugging, and running like ****. killed on me about 3 times, today it didn't kill or chug on highway, but then when at a stop sign she killed on me; had no power, then it came back on.. check my battery connection and my positive was kinda loose... I'm just lost on where or what to do now. Did I fry my TPS cleaning the IAC? I'm just so sick of this thing.

 

On vehicles of your year the tps has little on no effect on fuel delivery it is mainly used to shift the transmission. The IAC can not make it run bad only idle high or low. It is unlikely that either is causeing your problem. If you have a high idle and a misfire I would start looking for a vac leak.

 

Looked pretty good for vacumm leaks on it. Well wouldn't my best bet be the IAC then? Its idling extremely high.

 

Did you use a vac guage to verify?

 

Is the only symptom high idle? If it is running bad then IAC is not your problem. IAC stands for idle air control. It controls how much air is allowed in at idle only. How did you check for a vac leak?

 

I haven't tested it with anyone just looked. Details on how I test it?

 

You will have to get a vacuum guage & the specs from the manual or take it to a shop to have it tested for leaks/clogs in the system.