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91 YJ Fuel System Help

4.0 v6 MPI - Thank to your help on getting the tank down. It did take some convincing but it eventually dropped. I replaced the fuel filter and put in a shiny new pump. Connected everything back up, but left it down to test just in case I screwed something up at it did not blow up. There is still no pressure in the fuel rail. I hooked up a fuel pressure gauge and am getting some fuel in the line but no registering pressure. I am not hearing the pump come on at all. After quadruple checking connections and all lines under the vehicle I could find, I began thinking electrical. Disconnected the electrical connection to the pump and hooked up the DMM to the connector and turned the ignition to on, even as far as bring the starter on, but only mV levels are showing. Looking at the schematic and reading posts here, I am thinking it may be the fuel pump relay. Where do I find this (could not locate in the shop book). Any ideas on what else to test or look for. Again, a little fuel in the rail and dribbles out when pressing the relief pin, no spurt and no pressure registering with a gauge hooked up. Pump is making NO sound, even when pulled from the tank and car turned to on quickly. Thank again. First Jeep, and bought this for some 4x4 fun, and to learn how to do this stuff. The help you all provide here is invaluable.
Reply to
Chris
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Chris did pass the time by typing:

Not that it will help much but on the 93 ZJ there is a relay center just behind the battery.

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Start at the pump and follow the wires back. Color codes will stay the same (usually) all the way to the relay or fuse.

I'd be checking fuses also.

Reply to
cox-spamtrap

cox-spamtrap did pass the time by typing:

Now that was interesting. :) Used the wrong account, that was the one for reporting spam on the cox.net network.

Reply to
DougW

Be sure your ground is good.

Reply to
James Gemmill

The ground for the pump is on a bolt that holds the emergency brake pedal in place. I would be sure that is tight and hooked up.

There have been a mess of pump failures lately because of the e-brake recall. The 'techs', I won't call them 'mechanics', they aren't, aren't smart enough to make sure any wire got put back on tight when they swap the part.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Chris wrote:

Reply to
Mike Romain

Check the fuel pump ground near the e-brake mounting bolt. I heard there is a wire next to the emergency brake mounting bolt thats a fuel pump ground. I had starting problems and learned after a while that if I released the e-brake handle the rig would start. Still have not found the wire as in my case someone turned the e-brake handle upside down. When I turned the e-brake handle back so the text on the handle read right all my starting problems went away. But prior to that after releasing my e-brake I would hear my pump prime and the rig would start.

My gas gauge would always peg to full with the key in the start position if the fuel pump would not come on and would give an accurate reading when the fuel pump would come on.

Reply to
Ufatbasted

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