Fast idle problems

[rhe]

My 99 TJ 4.0 seems to be getting worse on idling fast, anywhere between 1500-2000. Does it at all different times, after warmed up, sometimes when it first starts, after sitting for a day or two, or after 10-15 mins. Haven't had any problem with starting or low idle, it's normally around 800-1000. But it seems to be jumping into the faster range more often. Any suggestions? Thanks in advance!

 

[StG58]

Try this first: https://wranglertjforum.com/threads/how-to-clean-your-iac-idle-air-controller-valve.662/

 

[rhe]

Thanks, I will certainly give that a try.

 

[StG58]

Thanks, I will certainly give that a try.

Cleaning the IAC becomes a maintenance item after awhile. It's cheap and easy to do. Good luck, I hope it fixes the issue.

 

[Chris]

Yep, clean that IAC and report back. With as old as our TJs are becoming, @StG58 is correct that it becomes a regular maintenance item. Cleaning it is free and easy!