My 2004 tj 4.0 nv3550, runs great for a while after a cold start, then just dies randomly at any rpm range. I had a bunch of random CEL codes like fuel pump relay control circuit, which i found fine, TPS voltage too high, I replaced tps with no luck, then i finally thought i had it solved when i swapped in a new crank position sensor, but then it died on me 30min down the road. It starts right back up runs for 30sec-5min then dies like its out of gas. The gauges all work after it dies still, am I looking at a pcm problem? What to I test next? I gotta get the jeep back on th road its my daily. Can't afford to take it to the shop.
As the intank pump ages it requires more power to run which creates more heat. Can be compensated by keeping the tank full. However, if the pump becomes too warm the internal protection shuts it down. Thermal Shutdown. While not known if this is the problem of the OP, it's very possible.
In the steering column the wires sometimes break off then rub each other. This causes the jeeps engine to run like sick dog. No problem until you need to change direction.
Not with the TJ. The pump is not cooled by being immersed in fuel, the pump is well cooled by the fuel passing through it no matter if the tank is full or nearly empty. If the tank empties so the pump sucks air, the engine stops which kills the power to the ASD (auto shutdown) relay which immediately cuts the power to the fuel pump relay which shuts off the fuel pump, and fuel injectors. The TJ's fuel pump and circuit design eliminates the possibility of overheating as some other fuel pumps can like you were thinking of. The TJ's fuel pump contains no thermal switch for that reason.
I think your exhaust is partially clogged up (cat or muffler). The key is the funny smell and the fact that it starts back up then die very quickly after.
If you let it sits for 15-30 mins or so, it should drive fine for another 30 mins.
No way a significant enough obstruction to make it not run at all would first pass enough to run for 30 minutes
Loss of ability for increased rpm yes but gas blocking building for a 30 minute run makes no sense to me
Ok so instill have my problem. I tested fuel pressure, naturally the jeep didn't act up the 45min I had the tester on it. Showed 51psi the entire time and held it there. I unplugged the clock spring no luck there either. Still dying ontermittantly. Ran fine for 2 hours the other day after I hard reset the PCM. Thought I had it figured out then it died again. I'm going to leave it in one of my bays at work with a scan tool hooked up and let it run until it starts acting up then see what pids are showing odd results.
You have replaced what is normally my first suspicion, the crankshaft position sensor. Personally, my next step would be the camshaft position sensor which is atop the shaft that held the distributor in older 4.0L engines.
The only reason I don't suspect my can position sensor, is because I replaced it less than a year ago and it's not making the clicking noise it was last time. How can I test it? Resistance test?
I'd suspect even a fairly new camshaft or crankshaft position sensor if it was bought from an aftermarket store like Autozone. Aftermarket sensors are notorious for causing problems which is how I learned to only go with Mopar.
i had the same problem with my 98 tj and it was driving me crazy, finally when i replace the the throttle position sensor and the crankshaft position sensor my nightmare went away,,, one of them two was the problem maybe you should check that up...
Thanks for the follow up and glad you got it figured out
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