I have a 99 XJ with 100k on the clock and it normally idles at 600 rpm but recently when i get to work and put it in park it idles at 1200... yesterday i went to start it up and let it warm up and it started at 600 and i was outside the car talking to my coworker then it just revved itself up to 1200... would this a vacuum leak or what?
Any suggestions on what to check would be really helpful

 

Clean your IAC first.

 

thats what i thought it would be to i cleaned it about 2k miles ago though

 

That would have been awesome info to include in your first post, eh?

 

i guess yea lol cleaning it doesn't mean that the parts not bad though