RPM Issues while driving

[nlocascio]

I'm having a weird issue with my 2002 V6 liberty. While driving, lets say 30mph, after i get up to speed, maybe 2200 rpm, when I let off the gas to coast the rpms drop of course. But not smooth. It will drop to 1800, then to 1500 and then back up. The car sort of jerks a bit as well. The neddle bounces. It then smooths out. Jeep idles fine, and no miss under acceleration. Also does not happen all the time, just enough to be annoying. Any ideas?

 

[LibertyTC]

The first thing to check is the operation of the throttle plate to ensure it is not sticking though normal operating range. Remove the air intake hose to the throttle body & with car not running, move by hand the throttle and note its smooth movement that it opens full & closes completely without sticking anywhere. Sometime some throttle body cleaner is often necessary to keep it clean. The next thing would be the IAC intake air control which does control the idle rpms and it may need removing & cleaning as well.
I assume you have no codes or engine light on..Also look for vacuum leaks..in any hoses

 

[nlocascio]

Will do. I have replaced idle air valve. Will check for vacuum leaks. Also my pcv valve makes a rapid ticking noise. I have replaced it and no change. And no, no check engine lights.