I have a 97 Wrangler. The other day it started to idle high. It Idles at 2200 rpm. It is not speratic. It runs just like it should but at 2200 RPM. I think it may be a vaccum leak somewhere but I looked everywhere and couldnt find one. Another thing that is puzzeling me is that I have no check engine light on. I did some tests on the Throttle Position Sensor and ruled that out as the problem. Any suggestions would help out greatly, I am stumped on this one.
Well, back to the drawing board. I cleand out the IAC valve and housing at with no effect. I did the TPS voltage test and it came back like this. 5V Incoming voltage. Which is correct. I did the output to test and at WOT it only read 3.9V when I was opening the throttle. I couldnt get it to go over 3.9V Should the range on a proper TPS get me closer to 5V? Does anybody know what the proper Volt range is?
Leaks are often hard to locate but my guess, since you have already cleaned the IAC, is a vacuum leak. How about spraying some WD-40 at where the intake manifold bolts to the head while the engine is running to see that makes the engine rpms change.