carencro xj

sometimes when i start my jeep it revs up to 2000 or 3000 rpm's and the only thing i can do to get it to stop is to kill it and start it again .and if that dont work then i just keep doing that until it does work. the most ive ever had to do that was 4 times . other than it doing that every once in a while it runs like new. my teacher is a master tech and we both cant find the problem. any ideas ?

fantic238

Replace the IAC (idle stepper motor) placed on the throttle body besides the TPS.

carencro xj

how do i check to see if its bad or you know thats the problem.

fantic238

Trust me.
If you want you can chech it in this way: when your jeep is running fine shut the engine off, open the hood, unplug the connector and restart the engine, if it doesn't rev up like crazy it's that.
Test 2: when it is idleing like crazy (3000), unplug the connector with the engine on, then shut off and restart and if ti stays at 3000 rpm no matter what you do, it's that.

carencro xj

ok ill let you know when im done.

Donnie_K

My wife's 89 wagoneer does the exact same thing. I kinda suspected the IAC. Let us know if that does the trick.

carencro xj

ok well i talked to my teacher today and he said we already looked at that and cleeaned it ,i forgot!!! so we tried cheking it with a scan tool i think he said to create a vacume leak to compensate fore the over reving idle. but it just so happenes that the machine had an error so monday hes bringing his own scan tool.

Hommersimpson

why didnt you test it the way sujested ^ up there

carencro xj

my teacher didnt want to idk why.

SeriousOffroad

Cleaning the IAC is fine and dandy, but you need to clean the entire TB thoroughly before condeming the IAC.

fantic238

Do it yourself!

McRay

I use good intake cleaner to clean air intake and replaced air filters when my rpm moves up and down at times.

carencro xj

i bought a new ica ,problem solved. thanks everyone.

fantic238