TJ fuel system gurus?

Offline246

TJ Enthusiast
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Oct 31, 2019
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NorthEast
Took the TJ wheelin today - nothing crazy, just bouldery, muddy NE trails on the side of a mountain. About 1/2 way up, jeep stalls. Dash lights, aux power, everything but ignition works. Rolled the jeep backwards, popped the clutch and it started. This happened 2 more times, common traits being that the trail was always uphill/semi challenging when it stalled. At this point, the grey matter kicked in and we turned around. Was towed down hill for a bit until I popped the clutch again and was able to drive all of the downhill sections under power. Ride home (30+ miles) was fine but slightly (at least) underpowered on the uphills.

Why would I loose power and stall on every uphill? Is this a wiring issue? Fuel pump? ??

Appreciate anyone's thoughts.

thx!
 
Last edited:
If it was definitely correlated to being uphill, I would check the floats in your carburetor. 😜

But seriously I would lean toward fuel pump but I would like to see the fuel pressure during normal driving and then on an incline. Out of curiosity, how much fuel was in the tank at the time?
 
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If it was definitely correlated to being uphill, I would check the floats in your carburetor. 😜

But seriously I would lean toward fuel pump but I would like to see the fuel pressure during normal driving and then on an incline. Out of curiosity, how much fuel was in the tank at the time?

2004 6 cylinder fuel injected. Definitely correlated to uphill. Only stalled out on uphills.

Additional info - when ignition was dead (after a stall), gas gauge read empty (it was a full tank).

How to you monitor fuel pressure while driving?
 
2004 6 cylinder fuel injected. Definitely correlated to uphill. Only stalled out on uphills.

Additional info - when ignition was dead (after a stall), gas gauge read empty (it was a full tank).

How to you monitor fuel pressure while driving?

An aftermarket gauge with a longer braided line.
 
I doubt that problem is caused by the fuel pump is sucking in air since its pickup sits down into a depression in the tank which is there to prevent fuel starvation when driving up or down steep surfaces. I wonder if the weight of the fuel inside the tank during a climb is causing the tank to pull back very slightly against its electrical connection at the very front-driver's side electrical connection of the gas tank. Among the other troubleshooting ideas given above I'd include reseating the fuel pump's external electrical connector at the front driver's side corner of the tank.
 
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Makes no since that it is a fuel pump if you had to pop start the vehicle with the clutch to get it started vice using the starter. I would look towards Jerry's recommendation on looking to a wiring issue.