Hello all,
I am having an issue with my 1989 Jeep Cherokee Limited 4.0L. It has a high idle at start up, going up to 2500 to 3000 rpm and it does't want to come down. Background info is that I have read through the forums and have seen several posts with similar issues and I believe I have tried all the fixes already. I refreshed all the grounds, and added the extra 2 ground cables that is mentioned in the instructions.I have thoroughly cleaned the throttle body. I have checked for vacuum leaks using starting fluid throughout the engine compartment, especially near the intake with no findings. I replaced the MAP sensor and IAC valve. I replaced the TPS even though it checked good based on voltage readings and the ground tested almost no resistance. I have probably done more, this is just what I can think of as of right now. The thing is, with the old or new TPS, once the engine is started and idling high, if you unplug the 3 wire plug from the TPS (engine side), it will idle down to 7-800 rpm. Then if you plug it back in it stays idling fine until the next startup. My question is what could be causing this at this point? Should I just leave it unplugged? Thanks for any help!!!