Engine Dies After 5 Minutes of Smooth Idling

[baremetl]

Hello all

I went to drive my 2000 TJ last week and ran into some problems. After 1/4 mile of driving, the low fuel indicator turned on but the gas gauge was still at 1/2 a tank. I turned around to head back home and the fuel gauge dropped rapidly to 0. I stopped to open my gate and while I was outside the vehicle, it died immediately (no sputtering or anything). I got back in the Jeep & it immediately started. I pulled it in & parked it. I suspected that the fuel pump was going out

Since then, I've started it many times and let it idle. The fuel indicator has read 1/2 a tank ever since the first incident. Every time I start it, it idles fine for ~5 minutes and then dies immediately with no fuel gauge changes & no low fuel indicator light. I tried swapping relays between the horn & the fuel pump but the problem persisted (idles fine for 5 mins then dies immediately). I hooked up a fuel pressure gauge to the fuel rail Schrader valve & started the engine. Pressure gauge read 47psi without any fluctuation for the full 5 mins of idle. When the engine died at 5 mins, the gauge did not move (still read 47psi). I do not see any noticeably loose wires, frayed wires, wires touching the exhaust or engine, etc. I do not have a check engine light nor any codes when I hooked up a code reader. Engine idles great & revs up just fine. No visible leaking fuel anywhere.

Other things to note:
- Jeep ran fine 1 month ago
- I live in central Texas & we had a cold snap recently where temps got down to 5 degrees
- Jeep is a 2000 TJ, 4.0L with no engine, fuel, air, exhaust mods
- No recent fixes to anything fuel, ignition, exhaust, or air related
- No history of anything related to this current issue

Anyone have any ideas on how to diagnose the root cause of this issue? Let me know if you need any more information & thx!

 

[Windrac]

You know this might sound silly... but pull your negative battery terminal and let it sit disconnected for 60 seconds.

Then plug it back in and drive it.

This sounds like a CANBUS communication problem to me. Pulling your (-) terminal will reset the computer onboard.

Try that and report back.

 

[qslim]

Hello all

I went to drive my 2000 TJ last week and ran into some problems. After 1/4 mile of driving, the low fuel indicator turned on but the gas gauge was still at 1/2 a tank. I turned around to head back home and the fuel gauge dropped rapidly to 0. I stopped to open my gate and while I was outside the vehicle, it died immediately (no sputtering or anything). I got back in the Jeep & it immediately started. I pulled it in & parked it. I suspected that the fuel pump was going out

Since then, I've started it many times and let it idle. The fuel indicator has read 1/2 a tank ever since the first incident. Every time I start it, it idles fine for ~5 minutes and then dies immediately with no fuel gauge changes & no low fuel indicator light. I tried swapping relays between the horn & the fuel pump but the problem persisted (idles fine for 5 mins then dies immediately). I hooked up a fuel pressure gauge to the fuel rail Schrader valve & started the engine. Pressure gauge read 47psi without any fluctuation for the full 5 mins of idle. When the engine died at 5 mins, the gauge did not move (still read 47psi). I do not see any noticeably loose wires, frayed wires, wires touching the exhaust or engine, etc. I do not have a check engine light nor any codes when I hooked up a code reader. Engine idles great & revs up just fine. No visible leaking fuel anywhere.

Other things to note:
- Jeep ran fine 1 month ago
- I live in central Texas & we had a cold snap recently where temps got down to 5 degrees
- Jeep is a 2000 TJ, 4.0L with no engine, fuel, air, exhaust mods
- No recent fixes to anything fuel, ignition, exhaust, or air related
- No history of anything related to this current issue

Anyone have any ideas on how to diagnose the root cause of this issue? Let me know if you need any more information & thx!

Are you experiencing this problem only on cold starts or does it start up & run for the five minute period when the engine is already warm?

I'm asking because a common symptom of a bad upstream O2 sensor is rough running/stalling once the engine is warmed up. When you start the engine cold the PCM ignores O2 sensor input & runs a baseline program to get the engine up to operating temperature. Once it's there it starts looking to the O2 sensor for input.

 

[baremetl]

Are you experiencing this problem only on cold starts or does it start up & run for the five minute period when the engine is already warm?

Initially it occurred every time, regardless of whether it was cold or hot

Updates:
Since my original post, I went back out Sunday evening & drove in circles around my neighborhood (didn't want to have to tow far if I broke down). Zero issues during 20 minutes of driving. This included coming to a complete stop every 1-3 minutes, and getting up to 45mph pretty frequently. Got back to my house & turned it off. Crossed my fingers & hoped it was some gummed up gasoline that needed to be burned off.

After reading y'alls responses, I went out this afternoon, pulled the negative battery cable, waited a minute or 2, put it back on, started it up. It died within 15 seconds but this time I had an engine code. Went & got my bluedriver bluetooth reader thing, plugged it in, started it up again, pulled the code (engine didn't die this time). Code is a P0340.

Did some research & found that this could pretty much be anything (cam position sensor, crank position sensor, ignition coils, bad grounds, frayed wires, bad 02 sensors, bad computer, etc.). Going to start with ordering a MOPAR cam position sensor & see what happens from there. Will report back once I learn more

Thanks for the responses btw & let me know if you have any other thoughts, advice, or questions

 

[bobcat]

@baremetl Did you install the mopar cam posiiton sensor? Is there an alignment needed after installing the sensor?

 

[baremetl]

@bobcat I finally received the Mopar camshaft position sensor (4897023AA) last week (originally purchased through Morris4x4Center but had to wait a couple weeks for them to email me saying that they didn't actually have the part.... Ended up getting it through amazon). I installed the sensor earlier today. Steps were:

1. Pop the hood
2. Disconnect battery negative
3. Remove sensor plug
4. Remove 2 9/32" bolts from the sensor head
5. Pull off sensor (no alignment or anything involved so long as you only remove the sensor)
6. Reverse install
7. Leave battery unplugged for computer reset
8. Connect battery
9. Start up the engine
10. Clear any previous engine codes with a scan tool (I use that bluedriver bluetooth tool)
11. Rescan

This resulted in smooth idling for a few minutes & no more engine codes. I've yet to drive the Jeep to see if it's truly fixed but I'll update the thread with my results once I get around to driving it

 

[baremetl]

Update:

I hadn't really driven the Jeep more than a few miles since my last post. I decided to go for a ride last weekend. Turned the key & nothing. Jumped it, it idled for a few minutes, then died. Took the battery in to autozone to test it & it was bad. Replaced it with a new Odyssey battery. Just installed it & turned it on. Let it idle to see if the root cause of my original issue was the battery. Engine died after 4 mins & 30 seconds. No sputtering or anything, just died. Almost like once some sensor or circuit got warm, then it decided to shut down. No engine codes. Going to mull over it for a while & potentially look at replacing the coil packs as a stab in the dark fix. They are 21 years old anyway...

 

[baremetl]

Update:

Ended up testing the new battery w/ a multimeter since I wasn't sure if it was fully charged after I got it from autozone. Tested it & it was at 11.59 volts. Took the battery out & charged it over 24 hours until it was complete. Tested it again & it read 13.10 volts (this was right after disconnecting the charger so I'm sure it would have dropped to closer to 12.6 if I let it sit a while). Reinstalled the battery. Found that my negative terminal clamp was too tight which didn't allow for the clamp to be fully seated on the battery terminal post & it could wiggle off. Opened it up with a flat head screwdriver so it would be fully seated & reinstalled. Fired the engine up. Let it idle for 7.5 minutes. No problems this time. No check engine light or codes according to my scan tool. Turned on all accessories while it was running & verified the alternator was good (13.85 volts with all accessories on, iow, headlights, brights, fog lights, radio, blinkers, fan, rock lights, air compressors).

I'm not holding my breath but I'm very hopeful that one of the root causes was this loose battery clamp

 

[Geep]

Just so you have more data, I'll tell my story. One day my 98 started being wacky.. it would start and run fine for several minutes then just die. Wouldn't start after that until it sat for a bit and cooled off, then same thing.
It was my temp sensor (the two wire one at the top front of engine). Once engine got warm and went into closed loop mode (where computer gets info from sensors to decide how much air & fuel to mix), it was getting faulty data from that sensor and just plain wouldn't run.
Replaced that sensor and it's been perfect since.

 

[CharlesHS]

Sounds like a Crank Position Sensor going bad....
As the temperature around the CPS heats up the Hall Effect sensor develops resistance and stop sending the proper voltage to the ECU. The engine will shut down and then as the CPS temperature cools the resistance drops and the voltage sent to the ECU returns to normal.
After the engine stalls.... try pouring cool water on the CPS; then try to restart the engine.

 

[bobcat]

Is your battery securely tied down with the clamps? I was missing the tie-downs and the battery cables were thrown loose by some bump on the road or a bad clutch release which caused the jeep to spring forward.

 

[baremetl]

Update:

Same problem persists. After my previous update, the issue popped up again after a few starts. Ended up replacing the Crankshaft Position Sensor (CKS) with a new Mopar sensor. Finally got it in the mail & finished installing that a couple hours ago. Fired it back up & now the engine dies even more frequently. Removed the negative battery for 10 mins to reset everything, reconnected, started the Jeep, & it stalled again after only a minute or two. This time, a check engine code popped up for P0340 (same code as one of my original posts above). Tried immediately starting again & it would easily start but die after a few seconds. Repeated that a few times to check for consistency (it was consistent). Very confused now.

@Geep: How did you identify that your temp sensor was the culprit?

@CharlesHS: At this point, I've replaced BOTH my camshaft position sensor (CPS) & my crankshaft position sensor (CKS). Both replacement parts are MOPAR

@bobcat: Yes my battery is secure

 

[Geep]

@baremetl it was a couple of years ago but if I remember correctly, I had just replaced the O2 sensors (can't remember if it was because of code or just because I bought it used and they looked like they'd never been changed) and perhaps that would have done the trick if I'd have reset the computer, but it still ran rough so I thought about what else "matters" sending data to the PCM in the difference between cold and hot engine, so I changed the temp sensor. And now that I think about it, I'm thinking I did a stovetop hot water test to measure ohms and it wasn't perfect.
So I've attributed the fix to that temp sensor... but it very well could've been the upstream O2 sensor that was the culprit.

 

[SkylinesSuck]

I chased my tail for more than a year with similar symptoms. Many people said bad PCM. Turns out it was the main harness.

 

[baremetl]

Forgot to provide an update & resolution (I hope) to this thread...

Back on July 17th, I replaced both the upstream & downstream O2 sensors (NTK 23151 & NTK 23099). Started the engine up & same problem as before. I then replaced all 6 spark plugs (Autolite XP985) even though all 6 looked fine & I also replaced the ignition coil rail (Mopar 56041476AB). Since this change, I have driven the Jeep 9 times for a total of ~150 miles and haven't experienced any issues at all. I highly suspect that the ignition coil rail was the root cause but I suppose there's a chance that it was a bad spark plug as well (they only had ~18,000 miles on them so I doubt any of the plugs were the problem)

Anyway, I just wanted to post my resolution in case someone else runs into the same issues that I did. That and I hate when I find an exact thread with the information I need but it dies prematurely with no resolution (didn't want to be "that guy" )