High Idle

southtj

Active member
I had the TPS replaced (along with many seals, bearings etc) and now the Jeep idles at a little over 1000 rpm. What should it idle at? Should I take it back to the shop to fix?
 
Should be closer to 700. I recommend removing the throttle body and all sensors from the TB. Then give the TB a good bench cleaning with carb cleaner and a tooth brush, paying special attention to the IAC housing. It's the half circle housing attached to the TB with 4 bolts and controls the idle.
 
I haven't had time to do this yet, Bounty, but I plan to soon. They replaced the TPS and did a fuel cleaning the first time I took it and that's when the problem appeared.

I took it back to Firestone twice for the high idle problem since they are down the street from where I work and it wouldn't cost me anything to fix the problem they caused. They couldn't figure out what was wrong and said it was either the IAC or the EGR valve. Do you think the fuel cleaning maybe gummed up the IAC and a good cleaning of the throttle body and IAC could fix my problem? I poked around and didn't see anything obvious as far as a vacuum leak goes and I mentioned it to them and he blew it off saying it would cause a much higher idle than the 1100 i've got.

I've got a cold air intake and a spacer on order so once those come in I'll do a good thorough bench cleaning of the TB and IAC. Any tips?
 

What kind of fuel cleaning? Was it injector cleaning?
 
TPS replacement. It's possible either they took off the TB and didn't replace the gasket or left something loose.

Is the high idle a smooth idle or is there a lot of poping? If they pulled any injectors the gaskets may be missing or leaking.
 
What kind of fuel cleaning? Was it injector cleaning?

It was a fuel system cleaning. This one.
Ever_wear_fuel_system_cleaner_VTS_ee_thu-1.gif


Is the high idle a smooth idle or is there a lot of poping?

No poping, it runs smooth. When I first start it up it revs up to about 2000 then settles down to about 1100. Sometimes it will drop to about 700 but 90% of the time it idles about 1100.
 

That sounds like a dirty TB and IAC. Take off the TB and remove the IAC. Clean it well including the IAC port. I use a Q-tip with almost no cotten to gently rub away the black build up. I do not touch or scrub the plunger, but I do rinse it well with cleaner. Check the gaskets adn reseat it. Be sure all the screws are tight and the gasket is in good shape. If this doesn't correct it. write back.

EDIT: Thanks for the tiny picture. It looks like the Ever Wear 3 step cleaner. One in the tank one in the TB and one in the oil. Correct? It is possible when you put the one in the TB you stirred up the dirt and it clogged instead of rinsing away. This would cause more air durring idle than needed and result in higher Idle.
 
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Re: High Idle - updated

Update almost a year later.

Two trips to Firestone right after they screwed it up by "cleaning" the fuel system and they couldn't figure out the problem.

AAA Automotive couldn't find anything wrong.

The Jeep dealer said that everything was operating within normal parameters.

I did take the throttle body off and cleaned everything I could with carb cleaner with no luck. So I tried to ignore it and didn't mess with it at all this year. Finally, I got tired of the reving up to 2000 when starting it and pretty regular idle at around 1200. I went to NAPA yesterday and bought an IAC for about $80. Firestone said they replaced the TPS but it didn't really look new so I bought a new one for about $30 and replaced them both yesterday afternoon in about 30 minutes.

Problem solved. So how is it that three repair shops couldn't figure out the problem or even if there was a problem but Bounty and JPNinPA nailed it without even seeing it?
 
Maybe they've got their heads stuck in their code scanners, and if their code scanners aren't throwing a code they're clueless.

Glad you have it figured out, I would have gotten tired of the high idle as well.
 
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