2000 Jeep Cherokee Engine stalls after warm-up

Tiny
CHRIS627
  • MEMBER
  • 2000 JEEP CHEROKEE
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 142,000 MILES
O.K. Here is the deal I have a 2000 Jeep Cherokee Sport 4x4 automatic that stalls after about 30minutes +/-. This goes back to earlier this year when it became hard to start. Come to findout it was the crankshaft sensor. Replaced and all was good. Then it started to act up again. 3months later. This time I had to have it towed, but I was near a parts shop so I borrowed their OBDII tester and it came up with crank or camshaft sensor. So, I bought the camshaft sensor this time replaced in the field. It started and died after giong around the parking lot one time. Called tow truck. At the shop they said the crank sensor went. They replaced it, I drove it one day and it died again. Back to the shop. This time they said the computer was dead. Jeep ended up back at my house after I got pi**ed-off at the shop for ordering the incorrect computer and letting two weeks go by without keeping me clued in on what happened. So, I have a car that dies after it warms up. It gets to just about 210 degrees and will shut-down. I have replaced all the above parts, switched the ASD relay with the cooling fan relay to no avail. I have checked all the connections and vaccuum lines. Nothing seems to be out of wack. I removed throttle body, disassembled and throughly cleaned. Looked for any broken connections or anything obvious. It was very dirty. Re-installed started it back up and it seemed to run normally, but then stalled. Also, removed the coil rail and tested it with an OHM meter and it checked out. I ran the OHM meter over every switch and sensor I could find and have pulled and checked every fuse. Everything is in spec.I got a fuel pressure gauge hooked up. According to the FSM it is supposed to read 49.2 psi +/- 2 psi, the reading on this thing is bouncing between 44psi and 50psi! Is that normal? Here is the fuel pressure information: 0 PSI cold engine key not turned, 46PSI cold engine key turned to on position, 46-48PSI engine started still cold at idle warming-up, 44-50PSI bouncing up and down engine at operating tempreture, 48PSI when motor dies.
Total time start to finish 31minutes 47seconds. You could almost set your watch by it! Possible regulator problem?
Anyone reading this, first off Thanks, secondly let me know what you think the problem is.
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Saturday, November 15th, 2008 AT 1:57 PM

23 Replies

Tiny
JNOVACK
  • EXPERT
You can check the regulator it is also your fuel filter but I would like to know if you have spark just after it dies the way to find out is just after it dies while wearing gloves remove #1 spark plug and with a test plug see if you are getting spark if not it could be the coil after it gets hot it stops working also when was the last time you did a tune-up
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Saturday, November 15th, 2008 AT 4:25 PM
Tiny
CHRIS627
  • MEMBER
This thing has a coil rail with 3-coils that bolts on to the engine above the spark plugs. How would I go about testing something like that?

It has been awhile since the last tune-up, about 70k miles, but I also checked the spark plugs and regap as necessary. I know that when it stalls I cannot get it to start at all. It has fuel pressure, but it doesn't feel like their is any fire. It reminds me of when the Crank Position Sensor went, it would just turn over but wouldn't fire. Does this help?
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Saturday, November 15th, 2008 AT 4:35 PM
Tiny
JNOVACK
  • EXPERT
Unplug wires from coils and check to see if you are getting 250-1000 ohms after it dies you may also need to take to dealer and have the software for the power control module (pcm) updated or even reprogramed they have the wright equipment to do this there is a service bulliton on the issue you are having I have had to do this to alot of jeeps from 1999-2003 that are high milage even on my own
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Saturday, November 15th, 2008 AT 5:02 PM
Tiny
CHRIS627
  • MEMBER
I will try this in the morning. As I had said I had tested the coil rail out of the car at room temp and it tested fine.
Why wouldn't this turn on the engine light?
I would think it should have kicked up a code.
Thank you for your help.
If I'm getting that high resistance on any of the pins will that indicate a fried coil?
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Saturday, November 15th, 2008 AT 6:59 PM
Tiny
JNOVACK
  • EXPERT
The 250-100ohms is the resisants you should get from the wire going to the coil it is known as the high tention wire the coil it self should have.71-.88 and this is what to test before getting to the power control module
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Saturday, November 15th, 2008 AT 8:07 PM
Tiny
CHRIS627
  • MEMBER
Now I'm confused.

I thought you were talking about testing across the pins on the coil rail itself to find this high resistance, but you are actually talking about probing across the unplugged connector back to the computer; is that correct? What happens if I find this high resistance? Are you saying that the computer is then in need of replacement?

I just read back through my original post and realized that I did not indicate that I did replace the original computer(PCM) with a new one.
Let me know if I'm getting this right. I was thinking that the coil rail may be fried, but now I'm not sure.
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Saturday, November 15th, 2008 AT 9:02 PM
Tiny
JNOVACK
  • EXPERT
Ok now since you replaced the pcm did you take to dealer and have it programed for our jeep they are the only ones with the password to set it up the wright way
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Saturday, November 15th, 2008 AT 9:15 PM
Tiny
CHRIS627
  • MEMBER
It came preprogramed. Using the VIN# & Mileage. The problem started with and was the same with the original computer.
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Saturday, November 15th, 2008 AT 9:26 PM
Tiny
CHRIS627
  • MEMBER
After going back and reading my first post to the last post and all the replies in-between I found that I had omitted one piece of information. I am currently running this Jeep with a remanufactured computer that I bought from Auto Computer Exchange. In my original post I spoke about the shop saying that the computer was fried and that I needed a new one and that they then ordered the incorrect computer. Well, after speaking directly to the mechanic he assured me that this was the problem, so that is when I ordered a ECM(PCM) from the above company. Installing this "new" computer made no difference in the 30-minutes to stall problem I was having and continue to have. Below is a complete list of the troubleshooting I have done to date. If anyone can divine, from this list what the issue is I will be eternally grateful. If not it will be going to the dealership sometime Monday. Thanks
1. Crank Position Sensor replaced. The CPS has tested good
2. Cam Position Sensor replaced. Put the old one back with no change in problem
3. ECM(PCM) Replaced problem still happens Old or New
4. Removed and cleaned Throttle Body
5. Tested the TBS O.K.
6. Tested all 4 of the O2 sensors O.K.
7. Tested Coolant sensor O.K.
8. Tested MAT Sensor O.K.
9. Tested the Coil Rail at room temp O.K.
10. Tested and swapped the ASD Relay O.K.
11. Tested and Swapped Fuel Pump Relay O.K.
12. Cleaned went through every connection both electrical and vacuum found nothing obviously wrong
13. Tested fuel pressure looks a little weird but I think it is O.K. See results; 0 PSI cold engine key not turned
46PSI cold engine key turned to on position
46-48PSI engine started still cold at idle warming-up
44-50PSI bouncing up and down engine at operating temperature.
48PSI when motor dies.
The last test I have to do is from a post on another site and involves the coil. This will be the last test and is either a pass/fail. Here is the test; Unplug wire connector from coil rail and check to see if you are getting 250-1000 ohms after it dies through the harness.
I'll also be pulling the coil rail to see if the resistance has changed.

Thank you for your help
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Sunday, November 16th, 2008 AT 8:49 AM
Tiny
CHRIS627
  • MEMBER
Here are the results of the test you suggested:
Pin 1&2 110.2K
Pin 1&3 219.8K
Pin 1&4 219.8K
Pin 2&3 110.2K
Pin 2&4 110.3K
I'm not sure what these values mean, but I hope they tell you something.
After doing this test I got silly because I'm out of ideas and ready to give up and take it to the dealership. See below-
Here are the results of my pull 1-sensor at a time test;
MAP Sensor died 10min. After it was started
IAT Sensor died after 30min.
IAC Sensor died after 16min.
TPS Sensor died after 10min. NO CHECK LIGHT CAME ON
Coolant Sensor 45min then died
Each time it died it would crank and not start. I then shot a little starter fluid into the intake and it fired right up. After all this was done I hooked up the fuel pressure gauge and I'm still spooked by the bounce of the needle. If you look my previous post, I put my the readings there. The high at the time I wrote this post was 50PSI, it is now at 52PSI the low is still 44PSI. Is the pressure supposed to fluctuate this much? I would think that having an electric fuel pump that the needle would be fairly steady. Assuming that the regulator was working properly. Could this be the cause of the stalling? Is there any way of testing any of the fuel parts in the tank without actually dropping the tank? Maybe through the electrical connector? Thanks for the help.
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Sunday, November 16th, 2008 AT 4:38 PM
Tiny
JNOVACK
  • EXPERT
Ok now test coil rail when it is hot lets see if you get spark in the plugs at this point
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Sunday, November 16th, 2008 AT 6:54 PM
Tiny
JNOVACK
  • EXPERT
Ok now lets test the coil pack when its hot and see what happens also check fuel pressure when its hot
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Sunday, November 16th, 2008 AT 7:10 PM
Tiny
CHRIS627
  • MEMBER
Fuel pressure when hot is fluctuating between 44psi and 52psi. I'll check the coil rail after it is warmed up and has stalled. I'll let you know whta that reading is shortly.
Thanks
O.K. I just pulled the coil rail while it was hot here are the results
Pin 1&2.9
Pin 1&3 1.9
Pin 1&4 1.7
Pin 2&3.9
Pin 2&4 1.1
Pin 3&4 1.9
Let me know if this tells you if the rail is good or bad.

Also, something to note, when it stalls I shoot starter fluid into the throttle-Body and it fires right back up. This morning it wouldn't start at all, but a little starter fluid and bam, on it came. What does this mean. Fuel pump maybe?
Thank you for you help.
Chris
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Monday, November 17th, 2008 AT 7:15 AM
Tiny
JNOVACK
  • EXPERT
Your readings are within limits Have you checked you O2 sensors you should have 2 one upstream and one just after cat they are a very common probblem but the fuel pressure should be staying steady ranging between 44.2-54.2 at engine idle you may have to get the pcm eather reprogramed or a software update I run across this alot in the shop I have even had to do this to mine but have been trying to save you the money now do one more you said that the tps (trodle position sensor) tested ok what is the voltage on center pin with throdle closed it should be.96 volts and wide open it should be 4.49 volts the rest of the tests I have require shop scaning tools but I am now leaning towards the pcm update
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Monday, November 17th, 2008 AT 5:58 PM
Tiny
CHRIS627
  • MEMBER
That is cool to hear about the coil rail specs. I was pretty certain it was good, but it was good to hear you say it.

O2 sensors checked out as well.

The fuel pressure is anything but steady. When I first turn the key to the on position it jumps right up to about 49psi and holds there. When the cold engine is started it starts to bounce just slightly, but nothing bad. Once the engine is warmed-up it jumps between 44-52psi. When the engine finally stalls it pegs the needle at about 49psi and doesn't move. The fact that whenever it dies or now that it has dropped below 30degrees regularly, I have to shoot starter fluid into the Throttle Body to get it started, I'm still thinking that there is a fuel delivery problem.

TPS tested Voltage closed (idle) =.816V, Open (full throttle) = 4.0V Not exactly where it is supposed to be, and maybe that is the problem, but I don't know.

The ASD relay is ever so slightly warm to the touch, but it is hard to tell. Plus it is now only 34degrees outside and the wind is blowing, if it was unusually warm I would probably notice a lot more heat.

Thanks for trying to save me money, and if you think of anything else let me know but, I'm thinking it is time for a trip to the dealership.
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Tuesday, November 18th, 2008 AT 10:55 AM
Tiny
JNOVACK
  • EXPERT
Ok change the tps and take to dealer there is a recall for the pcm being faulty I just found the recall it should be unlimited time and milage on all recallsthey will also set you up with the rest of recalls
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Tuesday, November 18th, 2008 AT 3:54 PM
Tiny
CHRIS627
  • MEMBER
That is great. So, I did the test on the TBS incorrectly the first time I did it. DUH!

I'll get the TPS replaced today, and make an appointment with the dealer. This would cause my stalling issue? I could kick myself for not testing this component correctly the first time!
Do you know what the recall/Service bulletin number is?

Thank you for all your help.
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Wednesday, November 19th, 2008 AT 5:55 AM
Tiny
JNOVACK
  • EXPERT
Don't bang your head on the wall it hurts beleive me I've tryed it but thats why we are her to try to help you with your repair issuse no not right off hand but all you have to do is go in and give them the vin # and they will pull up all recalls for your jeep and they will proform the repairs for all recalls
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Wednesday, November 19th, 2008 AT 9:31 AM
Tiny
CHRIS627
  • MEMBER
It has been awhile.

However, the sickness continues even after replacing the TPS! I had to get away from the Jeep for awhile and get some perspective. I was not getting anywhere and the money seemed to be draining away without result. I also, got a deal on an OEM fuel pump and free installation, so I went ahead and did that. I can now check that off the list.

Over the holidays I happened to be over at my brothers house helping unload gifts from my brother-in-laws trunk when I noticed he had an OBD-II tester in his trunk. Guess what I asked to borrow? The codes this thing had been kicking up, when it wanted to, were just the run of the mill crank & cam sensor and misfiring. Well I decided to drive it around with the code reader attached. The Jeep did what it normally does after a few miles and this time when the engine light came on I was ready. The codes I got are P0352 and P1391. The P1391 I have seen before, but the P0352 was new. My first question is does this mean the coil is bad or that I have a bad spark plug? My second question is should I replace the spark plugs first and give it a whirl or should I go for the whole works and get the coil with the sparks plugs? My third question is can the P0352 code be pointing to another component in the ignition system?

Let me know what you think.

Chris
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Tuesday, December 30th, 2008 AT 5:13 PM
Tiny
JNOVACK
  • EXPERT
Coil #2 should be replaced and the 1391 is for the crank and cam sensors giving Intermittent Loss of power you should test them I will get the test for you and send it
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Wednesday, December 31st, 2008 AT 7:59 PM

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