Hi. I was wondering if anyone could help me out. My 1988 Cherokee 4.0 has intermittent idle issues. Sometimes it idles fine but then other times it idles high (sometimes 1200 RPMs other times as high as 3000 RPMs). Sometimes it takes a few seconds and the idle drops back down to normal, other times it does not. I cleaned the throttle body and the IAC. I also tried to check the TPS but I am not sure if I was doing it correctly because my input voltage was high (6.4 volts). The instructions I read said it should be 5 volts. Thansk in advance for any help.

 

Check out cruisers renix tips. I would suggest bookmarking this page as you will use it over and over for as long as you own your jeep. I can say a new IAC fixed my random idle but it was due to taking the plunger thingy out while cleaning it which resulted in its untimely death.


https://www.cherokeeforum.com/f51/cr...x-tips-153657/

 

Check for vacuum leaks....for me it was a combo of a dirty IAC, vac leak and a bad TPS.

 

You definitely have grounding problems follow all of the tips ,,,,,do not just think the grounds are ok ,,,they are not,,,,,A Renix era Jeep lives ,and dies by it's grounds. The E.C.U. uses the ground circuit to control everything. Your idle problems are classic symptoms of a bad ground.

 

"Pink link" in my signature. Numbers 1,2, 3, and 5 to start with. Then #8 if problem persists.