Random Stalling?

[Hudson]

I have a 99 XJ that randomly stalls. Before i even begin describing it, if you remember about 2 weeks ago i figured out i had a bad battery. I never got around to replacing it, as i do not have the money to buy a new one at this point. I don't think this is related though, maybe it is.

Anyways, the Jeep randomly stalls when driving. I was driving down a main road today going about 45 MPH, cars behind me and what not, and the jeep just dies. RPM's go to zero, and i have to fight the steering wheel and pull the thing to the side of the road. Throw it in neutral and it fires right back up. I haven't found a pattern that it does it, it just seems to be intermittently. Any ideas?

OH, and i forgot to mention. I also noticed that if i push the gas pedal all the way to the floor when i'm driving (Wot), the RPM's will not go over 3,000 at times. Most of the times, they will not go over 3,000, but at other times they go up a little bit more.

[92xjlaredo]

I have a 99 XJ that randomly stalls. Before i even begin describing it, if you remember about 2 weeks ago i figured out i had a bad battery. I never got around to replacing it, as i do not have the money to buy a new one at this point. I don't think this is related though, maybe it is.

Anyways, the Jeep randomly stalls when driving. I was driving down a main road today going about 45 MPH, cars behind me and what not, and the jeep just dies. RPM's go to zero, and i have to fight the steering wheel and pull the thing to the side of the road. Throw it in neutral and it fires right back up. I haven't found a pattern that it does it, it just seems to be intermittently. Any ideas?

OH, and i forgot to mention. I also noticed that if i push the gas pedal all the way to the floor when i'm driving (Wot), the RPM's will not go over 3,000 at times. Most of the times, they will not go over 3,000, but at other times they go up a little bit more.

i had that EXACT same thing happen to my 95, threw about 500 bucks into it between fuel and ignition components...turned out to be a bad ECM. id say find a buddy with one to check against, or hit up a junkyard.

[Hudson]

i had that EXACT same thing happen to my 95, threw about 500 bucks into it between fuel and ignition components...turned out to be a bad ECM. id say find a buddy with one to check against, or hit up a junkyard.

Thanks for that. That is probably a good place to start. Where is the ECM located, and how much would a new one cost? I think there is a test somewhere to figure out if it's working correctly, i'll have to find it.

[92xjlaredo]

Thanks for that. That is probably a good place to start. Where is the ECM located, and how much would a new one cost? I think there is a test somewhere to figure out if it's working correctly, i'll have to find it.

well the ECM (electronic control module) aka your computer is located on the driver side fender under the hood there should be a little plastic cover over it, three plugs, and three bolts that hold it in place. theyre quite expensive new but at my local junkyard were 40 dollars a piece. i threw one in and it worked beautifully until the time i retired it. worse case scenario i have one in my garage that i could get to ya if ya wanted to cover shipping.

[ErikVilla]

I had that problem with a grandcherokee cutting out on the highway with no warning that it was gonna do it. it was the crankshaft position sensor. I put a new one in and it never happened again.

[Hudson]

well the ECM (electronic control module) aka your computer is located on the driver side fender under the hood there should be a little plastic cover over it, three plugs, and three bolts that hold it in place. theyre quite expensive new but at my local junkyard were 40 dollars a piece. i threw one in and it worked beautifully until the time i retired it. worse case scenario i have one in my garage that i could get to ya if ya wanted to cover shipping.

Alright i'm going to go looking for it. I'll start calling around my local junkyards to see if they have one i could pick up. If you have one laying around, i'd be more than happy to cover the shipping if you wanted to ship me one of em.

I had that problem with a grandcherokee cutting out on the highway with no warning that it was gonna do it. it was the crankshaft position sensor. I put a new one in and it never happened again.

Is there a way to find out if it's the CPS rather than the ECM? How much is a CPS? Should i just replace them both? This stuff is all over my head.

[ErikVilla]

Alright i'm going to go looking for it. I'll start calling around my local junkyards to see if they have one i could pick up. If you have one laying around, i'd be more than happy to cover the shipping if you wanted to ship me one of em.



Is there a way to find out if it's the CPS rather than the ECM? How much is a CPS? Should i just replace them both? This stuff is all over my head.

cps is like 35 located on the bellhosing of the transmission pretty easy to change one bolt and one connector just a pain getting up in there not sure how it is on an xj. pretty sure there are ways to test the electrical circuit but not sure how myself

[ErikVilla]

i would start with the simple stuff first look everything over make sure its getting good fuel and spark and check all electrical connections for the ignition system . could be something simple instead of just dumping cash on stuff that may not be bad.

[Ruepart Hoaxley]

Throttle position sensor? Where's your exhaust end? If your exhaust is shorter it could be vaporlocking, but it wouldn't fire right back up.

[LittleD]

If you have a noid light, you could see if the crank sensor is reacting consistently or if it's cutting in and out

[Hudson]

i would start with the simple stuff first look everything over make sure its getting good fuel and spark and check all electrical connections for the ignition system . could be something simple instead of just dumping cash on stuff that may not be bad.

I was actually going to get a fuel pressure tester and test the fuel pressure at the fuel rail. I might even be able to rent one from an auto parts store, or maybe they'll do it for me. I just recently (like a month ago) changed out the cap, rotor, plugs, and plug wires. Is there any easy way to check all electrical connections, or just to go each of them one by one and look at them?

Throttle position sensor? Where's your exhaust end? If your exhaust is shorter it could be vaporlocking, but it wouldn't fire right back up.

My brother changed out the TPS a little over a year ago. Is it possible for it to have gone bad again? What do you mean my exhaust end? Like where the end of my pipe is? It's like right under the rear hatch, but it doesn't protrude out. It's like flush with my rear bumper.

If you have a noid light, you could see if the crank sensor is reacting consistently or if it's cutting in and out

I do not have a noid light.

[92xjlaredo]

http://www.jeepforum.com/forum/f11/x...ensor-1167378/

heres a link on how to test the CPS, could be TPS...as well, theres a Camshaft position sensor as well right under the distributor cap (under the plastic cover when rotor and cap are both off. had one of them fray and cause me all kinds of little gremlins before. definitely run some tests before running out for a whole computer because it could be any one of the aforementioned things

[ErikVilla]

http://www.jeepforum.com/forum/f11/x...ensor-1167378/

heres a link on how to test the CPS, could be TPS...as well, theres a Camshaft position sensor as well right under the distributor cap (under the plastic cover when rotor and cap are both off. had one of them fray and cause me all kinds of little gremlins before. definitely run some tests before running out for a whole computer because it could be any one of the aforementioned things

perfect . This should make things a little clearer

[Hudson]

Thanks for the link.

I'll read up on it, and do the test tomorrow and report back here.

[Hydra]

Just so you know, if you need an ECM I have one from a 99 XJ and im in newmilf very frequently