Another fuel pressure failure thread..

my Xj has been down for 2 months. Over the last two months i have replaced alot of things, included is the gastank with one from a wrecked cherokee. my old fuel tank is in my back yard pile of parts..

i put about 15 miles on the jeep just testing new parts out..
Yesterday i Filled the tank for its first wheeling trip. everything seemed fine,
about 8 miles after filling the tank, it sputtered and died on the highway.

I checked spark, i have spart at the plugs. so its not the crank sensor.
I checked fuel. there is a purge valve on the fuel line. nothing comes out of that untill you crank it over, and then it just trickles out. without much pressure.

I checked power at the fuel pump, all sensors checked.

Now i have a Jeep that wont start with a full topped off tank of fuel. that wont start, and the sad part is, im thinkin its the fuel pump.

someone give me some insight, am i going to have to Empty this tank?:greensmok

what year.

on my 89 the tank doesnt need to be dropped but needs less than a 1/4 tank of fuel.

its an 89

i would also bypass the ballast resistor to rule that out as the problem.

Definitely check out your ballast resistor as 89xj mentions. You can take a piece of wire and run it across the terminals to perform the bypass if I remember right; it's been a while since I worked on my 88.

whoa whoa, step by step instructions? ballast resistor? bypass it?

There is a ballast resistor on the drivers side fender. Its a porslyn(sp) looking piece with two wires going to it. You can either just use a jumper wire to jump between the two posts or you can run a wire straight from your battery over to the front post. If you run the wire from the battery it will cause your pump to run even if the ignition is off. If you are just jumpering between the two posts it will just be bypassed.


I dont think it is your problem due to the fact that the electrical system should be bypassing it automatically while the engine is cranking but its quick to check and it wont hurt anything, so I would go for it.

You my friend. Explained that perfectly. thank you. I'll try it tonight! if i jump it and get it to fire, that would mean its Not my fuel pump?

VAwheeler said:

I dont think it is your problem due to the fact that the electrical system should be bypassing it automatically while the engine is cranking but its quick to check and it wont hurt anything, so I would go for it.

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I will have to respectfully disagree with that. The other day I knocked loose one of the wires from my ballast while removing my airbox. I didnt notice it and the heep wouldnt start. No fuel in the rail no matter how long I turned it over. Plugged it back in, and fired right up.