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Old 08-24-2014, 09:45 AM   #1
White3635's Avatar
Join Date: Nov 2013
Posts: 24
Fuel pump issues

I have a 1989 wrangler 2.5l throttle body injected.
Yesterday on the trail it shut down just like someone turned the key off. I have been experiencing fuel issues for a bit bit, fuel gauge doesn't work properly, and can't use more than 5 gallons out of tank or it starts hesitating.
If you pour fuel down throttle body it will start, pretty sure fuel pump is bad, only issue here is that while testing the connector from harness to fuel pump I only have 7.9v at connector. Checked and tested ground under dash by ebrake pedal and it changed voltage from 7.9 to 4.3 by disconnecting it and when hooking up with jumper direct to ground on battery only returned to 7.9v
Removed both relays next to battery and neither of them changed power at connector? Where is fuel pump relay or fuse? Connector is in good shape just not sure where relay is??? Thought I had the right one, found one more under dash at fuse panel but it changed nothing also.
Resent purchase and just figuring this thing out

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Old 08-24-2014, 02:38 PM   #2
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Join Date: Aug 2014
Location: Bama
Posts: 3

I am having similar issues. Except, when I turn on the ign switch I have no power to the fuel pump. I can run the pump using a separate battery and the pump will run, car will start and run, but as soon as I try to reconnect the three pronged connector at the tank everything shuts down.

I am thinking now a fuse maybe. Or possibly the fuel pump relay. But I changed that with one of the other relays and it didn't help.

I'll keep checking and maybe one of us will come up with a solution..

Mine is a 1990 with 2.5 tbi eng

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Old 08-25-2014, 12:29 PM   #3
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Join Date: Aug 2014
Location: Bama
Posts: 3

I may have a solution for you. I just finished mine and had two problems.

First- found a bad fuse on the panel (think it was a 20 amp). Noticed the buzzer for the key was not working. Replaced the fuse, buzzer worked and had power to the pump. Key on- power for a couple seconds till the relay kicked in. Turned the engine over and power was going to the pump.

Red wire with black tracer at three pronged connector at tank.

So, with power and the pump not working, I connected an external battery to the pump and low and behold, the pump worked. Next checked the ground on the three pronged connector. No ground !

I spliced a wire to the black ground wire from the car, grounded it to the chassis and we have a repair.

Hope this takes care of your issue also.
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