Engine Trouble

[Stampey]

Need HELP #-o #-o !
Hey guys today my Jeep started up normal, i drove for about 15 minutes, THEN at stoplight I noticed my rpm's going up and down crazily... Then all of a sudden it dies. I try to start it up again at the stop light, and nothin. I crank it for a bit trying to turn it on but wont turn over. So i finally managed to start her up and hobble to the side of the road where it died again. So on the side of the road i try to figure out the problem. I got no engine codes at all, and the that light only lights up on the dash were the engine, and a little oil can. So i checked the oil, level was fine it looked a good color. Well so i left my jeep on the side of the road, and had to get my dad to pick me up and take me to my math final!
I told him the story and he thought it was the fuel filter. Anyone experience anything similar to this? Engine is a 3.7L v6 automatic 2002
Any help at all would be great!

 

[Whelan]

No codes bein thrown could be a fuel filter, how many miles on the car?

 

[Stampey]

102k miles.

 

[Whelan]

Hmm,

Not sure how you can check if fuel is being sent or not, I know on older cars I simply open the TB and check to see if fuel is being spit in.

Anyone else know about this.

 

[JC]

If there are no codes my guess would be a dirty throttle body. I used to work in a shop and we'd see a lot of cars with the same symptoms do that.

 

[2003KJ]

Are you sure the fuel pump is coming on?

That would be the first thing i'd check.....gonna need somebody else probably to stick their head underneath the tank and listen for the pump to come on.

Could also be clogged fuel filter....although at 102K I have a hard time believing that unless you run your tank almost completely empty on a regular basis.

 

[JeepJeepster]

check to make sure its getting fuel. There is a pressure check valve on the fuel rail that you cna use to see if its getting pressure.

Sometimes you start right up after sitting for a sec and it will be fine. Ive seen that a few times on here.

At 102k, it very well could be the fuel pump though. O

 

[cowdogg]

How old is the air filter? Could be choking it.

 

[Stampey]

Airfilter is good, been checked regularly. Well we managed to get it to the dealer... So hopefully they can figure all the problems out with it. Will keep you guys posted.. Oh and btw when we got to the dealership, they said they are also scheduling me for new ball joints.

 

[indieaz]

It's probably the idle air controller motor. Chances are there some dirt/gunk built up in your throttle body causing it to have trouble opening/closing and the ECU can't figure out proper voltage to send to it based on current RPMs.

MAF sensor is also common cause of this - bud since you're getting no SES light i'm guessing that is not the case.

 

[Stampey]

Got it all worked out will post what the problem was in a sec. Here is the tech's report.

Tech-PO340 present cam position sensor circuit inspected sensor and connector, found engine will stuble when sensor vibrated after warmed up. Rec replace sensor and retest. Replaced Cam sensor and test drive 3 miles. Vehicle started to miss-fire and mil came on returned to shop and monitored cam and crank sensor signals. Found crank sensor signal would degrade and drop out when engine was warmed up rec replace crank sensor and retest. Note: Found large amounts of mud in chassis and lower mounted wiring harnesses and connectores. It is possible that there may be hidden damage to wiring and components from water and mud. Replaced crank position sensor. Started and let run for 45 min. Test drive 14 miles. System operating properly at this time....

OK well. we had them replace that stuff. ALL OF THIS FROM GOING THROUGH SOME DAMN MUD?? The dealer said to me that my car is not really ment for that type of stuff even though its trail rated and a 4wd jeep ????????? Well it really frustrated and kinda dampened my jeep spirit a little bit. Im now pretty hesitant to go offroading again, saying how one sensor can mess up my entire car like that. Has anyone else experienced stuff like this, cause i know some of you guys go offroading quite a bit. Or do you guys just think it coulda been a old sensor to start with?

 

[Stampey]

Bumpity bump

 

[2003KJ]

There are some sensors that are very picky about mud and water and stuff and they flip out when the slightest bit gets in them.

I'd continue to use your Jeep as a Jeep, and if you ever have this problem again, you might can get away with pulling the sensor off and cleaning it yourself.

 

[JC]

To me, it sounds like the tech was just trying to cover himself in case there is something he didn't catch. If that were me, and you got that in writing that you shouldn't take your jeep off road, then I'd contact the general manager. Just let him know that you feel that they are misrepresenting the product and that if you get any surveys you'll fill them out accordingly. Dealers make a LOT of money on their CSI Index and they will listen to you.