2004 TJ starts but slowly dies

redjeeper

redjeeper

Member
Joined
Jan 10, 2021
Messages
78
Location
Connecticut
Hey guys,
I took my automatic 2004 6 cylinder off roading last night and all of a sudden it just stopped.
Lights were working, gauges were good and the battery is fine.
Had to prime it a few times to get it going and slowly but surely made it out of the forest.
Seems like it’s running rich, the fuel pump is working so I’m not sure if something got wet or there’s another issue.
I can still get it to start but then it slowly dies, wanted to see what you guys thought before I start spending money to get it fixed.
Here’s a video to see what I’m talking about.
 

Attachments

  • IMG_2623.MOV
    13 MB
  • IMG_2623.MOV
    13 MB
I'm no expert, but I would check your ground cables to make sure that they are not only tight but not cracked.

The reason I say this is years ago I was riding my motorcycle across the middle of PA in farm country and my bike sputtered a bit and acted as if I ran out of gas. When I checked the ground wire to the battery I could see that the connection point was cracked so it wasn't making complete contact. The gentleman's house I stopped in front of helped me out with a repair and got me on my way.

Worth a shot!
 
X2 on the battery. I just had the same symptoms recently and my negative battery terminal connection had a crack.
 
the ebay tj said:
X2 on the battery. I just had the same symptoms recently and my negative battery terminal connection had a crack.
Click to expand...
I really don't think it's the battery, only a couple months old. I'm thinking its more of a crankshaft positioning sensor since the jeep has been losing power when I drive and then I have to wait to start it again. Transmission fluid levels are good too.
 
Codes are lean condition and O2 sensor heater and voltage malfunctions.

If you've never replaced the O2 sensors, I'd do all 4. Make sure to reference the O2 thread here for specific part numbers. Then, reset the ECM and reassess.
 
How do you know the fuel pump is good? I had exact same symptoms on a Chevy Silverado last year. It would pressurize with engine off and it would move fuel against no pressure but it couldn't hold pressure up with engine running. Only way to diagnose it was a running fuel pressure test.
 
  • Like
Reactions: RMETeeJay and Bargain Box
freedom_in_4low said:
How do you know the fuel pump is good? I had exact same symptoms on a Chevy Silverado last year. It would pressurize with engine off and it would move fuel against no pressure but it couldn't hold pressure up with engine running. Only way to diagnose it was a running fuel pressure test.
Click to expand...
I'm not 100% sure it is the fuel pump, but it was replaced a few months ago. I'm really hoping it's the crankshaft positioning sensor and the o2 sensors since I'm getting codes for that as well.
 
RMETeeJay said:
Codes are lean condition and O2 sensor heater and voltage malfunctions.

If you've never replaced the O2 sensors, I'd do all 4. Make sure to reference the O2 thread here for specific part numbers. Then, reset the ECM and reassess.
Click to expand...
I have not replaced the O2 sensors, will probably be doing that too. I am really hoping it is the crankshaft positioning sensor, since I've had symptoms of that malfunctioning.
 
Update: I replaced the crankshaft position sensor and it still starts up then slowly dies. Could it really be the o2 sensors preventing my car from running?
 
redjeeper said:
Update: I replaced the crankshaft position sensor and it still starts up then slowly dies. Could it really be the o2 sensors preventing my car from running?
Click to expand...
If it thinks it's lean it will flood the engine. If it thinks it's rich, it will starve the engine.
 
redjeeper said:
So yes to the o2 sensors
Click to expand...
Think of them as maintenance items that should be replaced every 100K. Since you have codes, it’s a no-brainer.

For the lean condition, @freedom_in_4low already gave you advice. It’s a pain, but not impossible to check fuel pressure on our later TJs. Did the driving issues start happening after the new fuel pump? What brand did you use?
 
  • Like
Reactions: freedom_in_4low and Bargain Box
RMETeeJay said:
Think of them as maintenance items that should be replaced every 100K. Since you have codes, it’s a no-brainer.

For the lean condition, @freedom_in_4low already gave you advice. It’s a pain, but not impossible to check fuel pressure on our later TJs. Did the driving issues start happening after the new fuel pump? What brand did you use?
Click to expand...

It's been a long time since I had a ckps issue and it wasn't on a Jeep, but it would either start or it would crank until I killed the battery. It never started, stumbled and died.
 
Alright guys, I’ve done all the sensors but bank 1 sensor 2. The sensor is off but it’s very difficult disconnecting it from the wiring harness. It’s hard to get a good grip and honestly I can’t tell if I’m pushing down on it or squeezing it

CA0B44FE-C671-4449-A4DB-676247126A9C.jpeg
 
redjeeper said:
Alright guys, I’ve done all the sensors but bank 1 sensor 2. The sensor is off but it’s very difficult disconnecting it from the wiring harness. It’s hard to get a good grip and honestly I can’t tell if I’m pushing down on it or squeezing it

View attachment 298675
Click to expand...
Hopefully it doesn't have that pesky lock tab...
 
Update: so I’ve replaced two of the sensors because the other two weren’t available but I tested it out and I noticed my fuel rail was smoking. This leads me to think it could be my fuel injectors… or I just need the other two o2 sensors
 
redjeeper said:
Update: so I’ve replaced two of the sensors because the other two weren’t available but I tested it out and I noticed my fuel rail was smoking. This leads me to think it could be my fuel injectors… or I just need the other two o2 sensors
Click to expand...
More detail on the fuel rail smoking...
 
Top Bottom
Back