[xtreme_jeeps]

About thirty seconds after start-up, my TJ goes to missing, spitting, sputtering and nearly will die. Once I push the throttle down one time real good, it goes away until I try to crank it and go again. It will do this at idle or during take-off when you need to get out in a hurry to merge with traffic. Can anyone help me with this?

 

[Jason R]

check the cps first...

 

[Sharp]

yeah, cps or tps

 

[Kilby]

Any of the sensors can make it act crazy. It starts like that... then goes into full-on Limp Mode.

 

[jeeperaaron]

No check engine light? Whats the mileage on the engine? 4.0L? Auto or manual? More info might help narrow itdown a bit.

 

[xtreme_jeeps]

98 tj with 2.5 with manual tranny and 110k miles. No check engine light. Some emailed me and suggested carbon build up... but where?

 

[Oxjockey]

98 tj with 2.5 with manual tranny and 110k miles. No check engine light. Some emailed me and suggested carbon build up... but where?

In your head.

 

[Tom Houston]

Run a can of BG44K fuel system cleaner. It will clean the injectors and get rid of any extra carbon in the cylinders. It runs $18 a can but works miracles. It is totally different than the STP type crap. If that doesn't take care of it, check the TPS. The CPS will tend to cause it to totally stall or always run crappy, not so much only at different throttle positions. The other thing to check is for a vacuum leak. That will throw off the mixture and the MAP/MAF control loop but won't be so noticable at higher speeds.

 

[jeeperaaron]

sounds like Tom Huston is on he right track does not hurt to clean the sh-t out of the throttle body with a tooth brush and, well a number of things work well , I have even used brake fluid. At that milaege on a 4 pop it's more than due. Then go from there and he is very right about the cps also, they either do or don't, I would lean in the direction of vacuum leak (check the manifold gasket) or next tps. you can always check your tps with a multimeter, basically you want it to read from low ma to higher ma consistantly as you go from closed to wide open throttle. if there are anomolies you probably have a problem.

 

[troyman]

Might try the o2 sensors and check for a cracked manifold. Mine was doing that for a while, (even back-firing) ended up going through two o2 sensors, two cats and on my third exhaust manifold. On mine, the pos manifold would crack, then the o2 sensor would go and then the cat. I heard a lot of people saying about checking the other sensors, but it never panned out for me. Ended up taking it to a five star dealer and had them check it out for like three days. They did everything from computer upgrade flashes to tune-ups and never did find anything. I had also heard to check the fuel rail and TPS even had one guy tell me it was due to running split-fires Personal feel was that it was a combination of the manifold and the sensors, would scare the crap out of you though trying to merge into traffic and it would just bog out...

 

[sw99]

o2 sensors! and it sure woulden't hurt to go down to the stealership and get a couple cans of the throttle body cleaner, like previously mentioned. It's about $4 a can and it's the MOPAR shit (not like it matters). The stuff works better than the other stuff I have tried in the past. Plus, it makes some cool white smoke that fills the street block, when you start it back up.

 

[xtreme_jeeps]

I will check most of these out, but as for the crack in the manifold... header! That little item was 150.00 and brought my fuel mileage up to about 14 mpg with 4.88's on 35's.

Jeep has been a real dream for the most part, but I know that now is when things are really going to head south. Allready have a 350 to start working in. Gotta have a back up plan!!