Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: AV.NINE on January 12, 2010, 05:59:15 PM

Title: Low Idle at stop light - WJ
Post by: AV.NINE on January 12, 2010, 05:59:15 PM
My mom has a 2004 WJ 4.0L

When stopped at a red the idle will go from 600-400 rpms, Ive searched and searched without victory but have heard other people have the same problem.

My first thought was fuel filter or dirty injectors. I have read some people have changed their TPS (throttle position sensor) and that has fixed it. I dont want to throw a whole bunch of her money away (well $45) on a new tps if that isnt the problem.

My plan of attack is some fuel injector cleaner then maybe a new tps.

Forgot to mention that a code does pop up once in a while but doesnt stay very long. I've never been there to check it when it does come on so I dont know the exact code.

I know this isnt very descriptive but has anyone else had this??  What do the jeep guru's think?
Title: Re: Need some idea's with mom's WJ
Post by: cLAY on January 12, 2010, 06:07:52 PM
Most momentary codes can be retrieved thru the computer. On my dodge trucks cycling the key 3 times displays them in the odometer window.

Often erratic idling is due to a dirt throttle body. Often spraying it down with TB cleaner will solve the problem, bad cases may need the idle control soleonid removed and cleaned seperatly.

However I've never worked on an '04 WJ so I can't say what will work...
Title: Re: Low Idle at stop light - WJ
Post by: AV.NINE on January 12, 2010, 06:10:46 PM
Thanks clay. Ill post some codes up as soon as I get back to RD tomorrow.
Title: Re: Need some idea's with mom's WJ
Post by: JackstandJohnny on January 12, 2010, 10:49:00 PM
Most momentary codes can be retrieved thru the computer. On my dodge trucks cycling the key 3 times displays them in the odometer window.

Often erratic idling is due to a dirt throttle body. Often spraying it down with TB cleaner will solve the problem, bad cases may need the idle control soleonid removed and cleaned seperatly.

However I've never worked on an '04 WJ so I can't say what will work...

X2.  had to do this at jeep jamboree in Penticton a few years back. had a bad seal on my intake, some dust got in, idle was very irattic, i found out coasting down a hill when it just stalled on me. sucked.  pulled air filter tube, sprayed it down good, and pulled the IAC and MAP to clean em good.  worked like a charm
Title: Re: Low Idle at stop light - WJ
Post by: AV.NINE on January 14, 2010, 05:09:46 PM
Took it to auto value and they put it on the comp. Said it was the TPS which I had assumed and BINGO!

Thanks guys.