Odd idle issue

[Itygr]

I have had a very small issue happen as of late. Occasionally while driving my tj has an odd idle issue. Engine idle drops to 3-400, upon giving it gas it fixes back to normal. I have replaced spark plugs, cleaned the iac and throttle body, recently did the starter (few months ago, and ran fine until now), and it has an optima yellow top that’s only two years old giving 14v. Starts have been great for the most part, usually only happens when driving. Not sure what to look at next. Thanks!

 

[macleanflood]

Make smoke test the vacuum lines and check for leaks?

Could be the throttle body.

And check grounds. Check then again. And clean them all!

-Mac

 

[TonyArms]

I have had a very small issue happen as of late. Occasionally while driving my tj has an odd idle issue. Engine idle drops to 3-400, upon giving it gas it fixes back to normal. I have replaced spark plugs, cleaned the iac and throttle body, recently did the starter (few months ago, and ran fine until now), and it has an optima yellow top that’s only two years old giving 14v. Starts have been great for the most part, usually only happens when driving. Not sure what to look at next. Thanks!

Did you try to relearn on the iac memory ? that seems to fix my rough idle

 

[Lucky!]

Run throttle position sensor test with a multimeter. Had something similar started with idle then started cutting out at higher speeds, turned out it was a bad TPS. If needs replacing you have to spend the extra $ for Mopar. Certain parts especially this sensor should be OEM.

 

[Itygr]

Make smoke test the vacuum lines and check for leaks?

Could be the throttle body.

And check grounds. Check then again. And clean them all!

-Mac

I’ll check them tonight! Throttle body looks good. Never smoke tested at home. Maybe if I can’t find anything else.

 

[Itygr]

Did you try to relearn on the iac memory ? that seems to fix my rough idle

I tried that when I cleaned it and it’s still causing issues. Is there another way other that disconnecting neg?

 

[Itygr]

Run throttle position sensor test with a multimeter. Had something similar started with idle then started cutting out at higher speeds, turned out it was a bad TPS. If needs replacing you have to spend the extra $ for Mopar. Certain parts especially this sensor should be OEM.

Will try!

 

[Jeepster97TJ]

Did you try to relearn on the iac memory ? that seems to fix my rough idle

How is this accomplished? I did the IAC and throttle body clean out and seem to work for a little while but I still have an occasional low idle like the OP described. If I rev it up it seems to go away. So I believe it is the IAC still but not sure what the next step it.

 

[Itygr]

Will try!

Run throttle position sensor test with a multimeter. Had something similar started with idle then started cutting out at higher speeds, turned out it was a bad TPS. If needs replacing you have to spend the extra $ for Mopar. Certain parts especially this sensor should be OEM.

I have some odd readings. Power reading 3-4v

 

[TonyArms]

I use a scan tool to do the relearn.

 

[Itygr]

Update. Just replaced the tps. Seems to be back idling around 750 consistently. Time will tell now!

 

[TonyArms]

Good Deal ow its fixed.