Idle problems when clutch is in

[TJ Dynamics]

Whenever I am at a red light and have the clutch in or is in neutral the engine revs to 3500 to 4500 RPM he will not stop until you release the clutch and takeoff again if any has suggestions on how to fix this I would greatly appreciate it Thank you

 

[AndyG]

Whenever I am at a red light and have the clutch in or is in neutral the engine revs to 3500 to 4500 RPM he will not stop until you release the clutch and takeoff again if any has suggestions on how to fix this I would greatly appreciate it Thank you

What year TJ. Sounds like a PCM issue if 04-06 but could be the idle air controller ...that comes to mind.

 

[Steel City 06]

Bad vacuum leak?

Does it occur at all times in neutral or with the clutch in? Or just during certain situations?

One thought I had is if the vacuum brake booster is bad, you may see a significant spike in RPM when you depress the brake pedal

 

[qslim]

Whenever I am at a red light and have the clutch in or is in neutral the engine revs to 3500 to 4500 RPM he will not stop until you release the clutch and takeoff again if any has suggestions on how to fix this I would greatly appreciate it Thank you

Any maintenance done recently? Sounds like a bad vacuum leak. Does it do it all the time from a start or only after you start driving?

Also finish filling out your profile with the particulars of your TJ, it makes it easier to people to help out when they can see what you're driving.

 

[Jeepn_Texas]

Whenever I am at a red light and have the clutch in or is in neutral the engine revs to 3500 to 4500 RPM he will not stop until you release the clutch and takeoff again if any has suggestions on how to fix this I would greatly appreciate it Thank you

You don't have your jeep stats listed... I'm new.
Year, Engine, etc...
Your Idle air stepper may be Kaput!
Any other symptoms?

 

[TJ Dynamics]

Bad vacuum leak?

Does it occur at all times in neutral or with the clutch in? Or just during certain situations?

One thought I had is if the vacuum brake booster is bad, you may see a significant spike in RPM when you depress the brake pedal

It happens all the time, when you push the brake in and release the clutch slowly the idle will go back to normal.

 

[TJ Dynamics]

You don't have your jeep stats listed... I'm new.
Year, Engine, etc...
Your Idle air stepper may be Kaput!
Any other symptoms?

2000 Jeep Wrangler tj 4.0 straight six 4wd. No other symptoms just what I listed .Thanks

 

[TJ Dynamics]

Any maintenance done recently? Sounds like a bad vacuum leak. Does it do it all the time from a start or only after you start driving?

Also finish filling out your profile with the particulars of your TJ, it makes it easier to people to help out when they can see what you're driving.

No maintenance recently except the usual oil change .im also thinking bad vacuum leak but where would I start looking for that at . Thanks for your comment

 

[Steel City 06]

I would start by looking for vacuum leaks.
Try this test:
https://wranglertjforum.com/threads/cheap-engine-vacuum-leak-tester.19643/
Then try cleaning the IAC:
https://wranglertjforum.com/threads/how-to-clean-your-iac-idle-air-controller-valve.662/

 

[qslim]

No maintenance recently except the usual oil change .im also thinking bad vacuum leak but where would I start looking for that at . Thanks for your comment

If you haven't had anything apart recently I'd be looking to the IAC and then look at checking for vacuum leaks like @Steel City 06 suggested. I've had occasions (not on the TJ, but my other cars) where I tapped on the IAC with a little hammer and the idle dropped back down to normal. Carbon and gunk can build up in there and keep the valve from turning, cleaning it is pretty straight forward.

BTW your factory manual is in the "TJ Resources" forum, you can get the PDF for free if you need to see how stuff comes apart and goes back together.