1997 Jeep Cherokee Engine stalls

Tiny
NEMA38
  • MEMBER
  • 1997 JEEP CHEROKEE
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 172,000 MILES
I have a Jeep Grand Cherokee.

Guys, I really need help, I have taken my vehicule with a lot of "mechanics" and all that they have been doing is to make me spend money.

When first started failing the problem was that the engines was stopping either when cold or hot, the mechanic said that it was a problem with the gas pump so I replaced it but the problem didn't go away, then I took it to warranty and the pump was replaced it for another new but guess what? Same thing, after this was obious the problem wasn't the pump, so I took it now with an electric and this guy made me replace the computer (expensive) but I bought it hoping this would solve the problem but again the same problem.

After all this of expending money I googled it because it was obious these guys didn't know what they were doing and I found that this problem may be caused for the harness that is pluged in the computer and in fact there was the problem, I found some pins with the plastic locks broken, I replaced the harness and the problem seems to be gone, at least now was not been shutting down my engine every time I hit a bump or a hole because with the movement the conections in the harness became loose.

After I fixed the problem with the loose conection my only problem is that when cold after around 10 minutes of start running the engine just dies, suddenly and when I try to restart it, it does right away, no problem.

Then I decided to took it with another mechanic and he told me the problem was the IAC valve so I changed it and the same thing, after no sucess with this guy I went to a different place and at leat this guy was honest and since there was not "check engine" light up his suggestion was to change the crank shat sensor and I did it hoping this would be the solution but it wasn't, this morning did the same thing, after runing for 10 minutes the engine stopped.

Right now I don't know what else to change and hope this time I have more luck.

Please advise
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Sunday, June 27th, 2010 AT 11:49 PM

5 Replies

Tiny
CARADIODOC
  • EXPERT
Hi nema38. Welcome to the forum. The crankshaft position sensor is the most logical and common cause of the problem you're describing but the air gap is critical. They come with a paper spacer or a plastic rib on the end. The new sensor must be pushed in all the way before it is tightened. If it is not adjusted properly, it can cause intermittent stalling. When a sensor is removed, then reinstalled later, the remaining part of that rib must be cut off and a paper spacer must be stuck on to set the gap. If it is not used, it is possible for the sensor to hit the flywheel or flexplate and be broken.

You're trying to fix this the most expensive and least effective way. That's by asking one mechanic to guess at a solution, then buying the expensive parts and installing them yourself. Also, bouncing from one mechanic to the next is not productive. That's like switching from one doctor to another one if he doesn't come up with the correct diagnosis on the first visit. They will keep performing tests until they DO find the cause of the problem, but you have to give them the chance to do more tests. If you let the mechanic keep the van until it is fixed, it will be done. I doubt you needed the fuel pump or the Engine Computer. If the mechanic would have put those parts in and they didn't solve the problem, he would have taken them back out and continued looking for the cause. By constantly going to different mechanics, they all are going to start over with the same diagnostic steps and you'll be paying for their service over and over. When they make a diagnosis and it turns out to be wrong, you wasted a lot of money on the wrong part. When they make a wrong diagnosis and THEY put the part in, that is just the first step. They continue to perform tests that lead them to the problem. In your case, they aren't continuing with the testing. They stop at the most likely cause because you take the vehicle to replace the parts yourself.

Does that make sense? I know I didn't do a good job of explaining it, but you're better off sticking with just one mechanic. No one always comes up with the correct solution with the first thing they test or try. They might have to test a dozen things before they find the problem, but you're not giving them the chance to go beyond the first thing.

Caradiodoc
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Monday, June 28th, 2010 AT 2:06 AM
Tiny
NEMA38
  • MEMBER
I agree to keep the same mechanic make the fix, just that the last fix I didn't do it by myselft the electirc did it and by the way that paper spacer you are talking about it the mechanic didn't know for what was meant for and he took it before installing it, I told him for what was meant after reading the instructions but he took it anyway, let me take it again and make sure the air gap is ok, Do you know how much this air gap must be?

By the way when a mechanic doesn't know for what are this paper spacers something is wrong, don't you thing so?

Thanks.

Manuel Chavez
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Monday, June 28th, 2010 AT 10:17 AM
Tiny
CARADIODOC
  • EXPERT
Not all mechanics are familiar with every part on every car but for sure he will learn after breaking one of these sensors.

The correct air gap is the thickness of that paper spacer. There is no way to measure it because it is hidden. The spacer will slide off as soon as the engine is started.

While working at the dealership, I replaced 13 transmissions over a two-year period. On the last one, I didn't use that spacer when reinstalling the sensor. I just pushed the sensor all the way in, then pulled it out a little. I heard later that the engine ran fine for two weeks, then began stalling intermittently. The next mechanic diagnosed an intermittent sensor. The engine ran fine after he replaced it. Had he known the history about how I didn't follow procedure, he could have fixed it by just reinstalling the sensor properly with the spacer.

Caradiodoc
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Monday, June 28th, 2010 AT 2:19 PM
Tiny
NEMA38
  • MEMBER
Cardiodoc,

I already took out the sensor and I didn't see any damage, so I went to autozone to ask them to show me a new sensor and from that one I got the dimension of the paper spacer, it is 0.75 mm, then I made a spacer and glued it (the one that the kids use for school) and installed it again, all the way in until it touched the bottom.

This was around 4 PM and then I started the engine and I kept it running for around 20 minutes and no problem, then I took the jeep for a ride and still no problem, but the next day around 8:00 AM I started the engine and it did with no problem but after 1 minute +- 3 seconds the engine just stopped, it rattled a bit (2 seconds) and then died, I tried to start it again, first time failed but in the second one did it and stayed running with no problem.

Pelase advise

nema38
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Sunday, July 4th, 2010 AT 10:43 AM
Tiny
CARADIODOC
  • EXPERT
Well, I think we can rule out heat-related issues. That's one way sensors and computers fail. That kind of leaves the wiring as the likely suspect. While the engine is running, wiggle harnesses around and pay particular attention to electrical connectors. Fuel pumps rarely quit once they're running but don't overlook the wire going to the tank. A clue the stalling is due to an electrical issue is the engine will suddenly stop just as though you turned the ignition switch off. If loss of fuel pressure is the problem, the engine will slow down and sputter over a period of a few seconds.

Caradiodoc
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Sunday, July 4th, 2010 AT 4:11 PM

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