johnpwrc

Hi,

I have a 2000 Cherokee Sport 4.0L with 72k miles.

Recently I've had trouble with my Cherokee randomly stalling during driving. The car runs fine most of the time, but randomly the car will buck violently - but keep running - or just flat out stall and die. It hasn't thrown a Check Engine light yet, so I have no codes to look to for a diagnosis.

My local mechanic took a look at it, and can't seem to find any problem. We thought it might be fuel related, but the pump and pressure in the system seem to be fine.

Now I am leaning toward an issue issue with the plugs/wires. I'm thinking there might be a problem there, since the car tends to behave like it has trouble getting spark and keeping the engine moving.

Has anyone on the forum experienced an issue like this before?

I'd welcome any thoughts/ideas any of you might have.

Thanks!

John

Willys55

sounds like the crank sensor is failing

johnpwrc

Thanks for the reply.

How involved/expensive is the replacement of the crank sensor?

If this sensor was bad, would it throw a Check Engine light?

I'm trying to narrow this down so I can avoid just throwing parts at the car

Thanks

ATVracer76

ok, i seem to be having the same issues. a violent buck where the motor cuts and starts right back up. my gauges even drop like i lost all power and bounces back on. i replaced my crank positioning sensor and i havent had it on the interstate so i havent had any bucks but when i start it to warm it up, itll just stall out in the drive. it has always started right back up but today i backed out of the driveway and it stalled. started back up again but i see all the stories about peoples jeeps leaving them stranded and they have to come back to it the next day before itll start again and i dont want that happening to me. the jeep also seems to have a low idle and its kinda ruff running. at least compared to my last jeep... some jeep god please tell me what i need to check to make er right.

thanks

ATVracer76

The more I search the forum, the more I see something about the idle air controller valve/sensor. Where is that located on the motor? I'm gonna clean up the throttle body too while I've got it in a warm garage. Any other tips or tricks?? Thanks

azxj99

I'm having the same problem. Replaced my plugs and wires. Stalled out just sitting at the light and no check engine light....

wildspear

Check the "crankshaft position sensor". Get a meter and check the leads in the plug. There is a write up to do the test. I just replaced mine yesterday. It was a pain in the rear because its hard to get to. but all you do is unplug, remove 2 7/16 bolts and replace with new one. I bought mine at "Autovalue" for 31 dollars and change. Cheaper if you order online.

davida

Even though your check engine did not come on did you check it for trouble codes? Another thing that causes what you are describing is a O2 Sensor. The PCM relies on the O2 Sensor's to tell it about the burn in the cylinders down line in the exhaust by monitoring the Oxygen in the exhaust. This is one part of what the PCM uses to adjust injectors, airflow and spark.

davida

Don't forget to check in to this thread and let everyone know what fixes your problem.

troy fritz

Pull the tps ,iac and clean them before dumping $ into it.Also try adjusting the tps.There is a bullit looking thing on it when you pull it out ,just turn it one way or the other and see if that helps.I have had plug wires go bad and it does make it buck alot.But I've never had it stall the motor.I would lean more towards the sensors.I had a tps go and it did this.Cps could also be bad.

Dracos

OK, I have also started to have these problems with my Jeep. It's a 1988 Cherokee with 160k miles on it; inline 6, 4.0. It cuts off for no apparent reason as I drive it, and will restart easily enough. It runs rough when it's going; lots of vibration. I've recently completely replaced the transmission fluid and oil, as well as changed the filters. I'm going to try the ideas shown here. If anyone does before I get to it, results would be appreciated.

ken72

this sounds like bad injector issues. First thing I would do is pour a full bottle of injector cleaner in half a tank of gas. let that burn through and see if it gets better. Rough running and a bucking engine are usualy a sign of a bad injector. A mechanic can even hook it up to a diagnostic machine and tell you which injector it is if that is the issue. I do agree with the TPS as well so get some Throttle body cleaner and clean that up as well.

Dracos

Okay, this has also been told to me once before. I ran a bottle of cleaner through the system on a full tank, and it settled down, but only for a short time; I'll give the half tank idea a try as well.

A friend of mine is also suggesting that it might be something to do with the alternator not putting out enough voltage. I just bought it off someone who drove it pretty hard in mud and such without doing a complete seal and protect job on it. Looking at the alternator, it has traces of mud and even some strands of old grass on the outside, making me think he might be right... think it would be a good idea to replace the thing completely, or is it just a matter of cleaning it in some way?

This is my first car, so any suggestions on improving it will be much appreciated; I'd like to get it back to being roadworthy without worrying I'm messing it up worse just by driving it.

ken72

If running a cleaner through it settles it down for a little while I would guess your dealing with bad injectors. It could be just one injector or all. I would get some from the JY and replace all of them. Or look around them and see if any of them appear to be leaking. You will notice some darker color around the injector on the manifold like it is wet. Get a set of injector seals for just a few bucks and remove the rail and injectors and look them over. See if any look like they have some carbon build up. Clean them all up and reinstall. Search for write ups on this so you reinstall them correctly. I did this a few months ago and it was very easy. This is a cheap solution before you go out buying new parts. You might even find a place that will test them for you for free if you take them out.