Warm Idle stall Procedure?

[CHARLES NELSON]

I have a 2002 with 3.7L autotrans.
After the engine warms up, and I come to a stop...the rpms drop
to below 700 and the engine stalls.
If I put the trans into neutral to decrease the load on the engine...it
continues to run.
The cold idle works perfectly fine.

I took it into the Dealer and they 'spray cleaned the throttle body mouth' and
charged me $140.00...afterward it still warm idle stalled! Dealer said they needed to do an 'induction cleaning' which would run about $250-300.

A second dealer stated that almost certainly (even without looking at the engine) they would have to replace the complete throttle body assembly!

I asked both dealers why they couldn't adjust the warm idle faster via the internal computer and they told me that it was IMPOSSIBLE to adjust
the warm idle!

A friend of mine suggested that the repair shop 'check the IAC and TPS sensors'...I called back both dealers and was told that no one at either
shop knew how to either check or adjust the sensors.

Does anyone have suggestion on how to proceed?
1) an induction cleaning
2) a full throttle body replacement
3) continue with diagnostics and check the sensors (and how
to determine if a shop has the capability to do so)

Thanks
computer and both

 

[Dave]

My first guess would be the throttle body clogged with deposits, but you said it was cleaned. Sounds like the IAC is not working properly. (Idle Air Control) It is located on the side of the throttle body. The PCM controls the IAC but if there is no other issue I would think the PCM is ok.

I am just guessing here from what you said. You have no codes?? I would take it to an Advance Auto because they will put a code reader on it and check it (free) in the hopes of selling you a part.

Dave

 

[JeepJeepster]

Yea, thats what I thought too dave.

http://www.jeepforum.com/forum/showthread.php?t=515244

 

[Prospect62]

Welcome CHARLES NELSON. To answer one of your questions, the idle speed (warm or cold) really cannot be adjusted or changed on today's modern fuel injected vehicles. It is controlled almost exclusively by the engine computer. What the guys have told you so far is right on...you must be having some type of sensor or valve malfunction. How many miles are on the Jeep? Has it ever been in for a tune up (new plugs, etc)? Usually when stuff like this happens, it is accompanied by a check engine light. Yours isn't on?

Also, I have to say that a complete throttle body replacement is almost certainly NOT NECESSARY. I'd get some throttle body cleaner and spray it around again, look at the Idle Air Control Valve ($90), the Throttle Position Sensor ($35) or the coolant temp sensor ($23). I don't really know. But before you pay the stealer to change the whole damn throttle body, check the small stuff first.

 

[offrovering]

first go get your money back, that is why they get the name, stealership

second, I would check IAC , then look at TPS, you can clean the TPS, my other vehicle had dirty TPS which after cleaning up helped cure stalling or very low rpm at idle.

your buddy may be able to look/help? brake cleaner can be used to clean sensors, be gentle though.

guys around here will know more on the jeeps specifics and what to use

 

[tjkj2002]

on the 3.7 V-6 the warm idle speed is between 625-675 RPM.Do a tune-up(plugs,air filter,fuel filter,pvc valve) and clean the throttle body and IAC.

 

[robertgriggs1]

The idle air control on my jeep was filthy. Cleaned it up and everything works great on idle now. Thanks for the tip!
Rob

 

[LibertyTC]

See below: Some problem with KJ Server this am real slow?

 

[LibertyTC]

IAC Cleaning With photos Link

In this link: http://www.jeepkj.com/forum/showthread.php?t=47972
I posted some photos about cleaning the IAC.
Sometimes the plunger acts to quickly and it causes a stall.
If the plunger has some good resistance, like wanting to bend the q-tip while depressing, all is good. Otherwise replace the IAC. I normally just clean it and re-install.
If problem persists do clean the port and then replace the IAC with a new OEM part.

 

[k99jk99j]

The idle air control on my jeep was filthy. Cleaned it up and everything works great on idle now. Thanks for the tip!
Rob

cleaning the iac is suppose to be part of the throttle body cleaning. don't go back to that dealer. mike

 

[MadDog]

I remember reading somewhere but I can't find it now, how do you remove the IAC for cleaning? Do I remember reading that you need a Torx bit?

 

[LibertyTC]

http://www.jeepkj.com/forum/showthread.php?t=47972