1993 Jeep Cherokee 6 cyl Four Wheel Drive Automatic 104000 miles
I have a 1993 Jeep Cherokee. Was driving it and it quit running. Had it towed. Key on sends 12V to the fuel pump for just a brief second, but does not energize fuel pump. Of course, I replaced pump and filter. Still no fuel pump engagement. The fuel pump will run if I put 12 V to it, but I am not able to get it to prime and send fuel to the rail, tank is about 1/4 full. Back to the real problem. I do not have 12V to the fuel pump except for a few milliseconds. I have checked ALL the fuses (3 times, because sometimes I am stupid), I have replaced the fuel pump relay. The fuel pump relay has always made an audible click indicating mechanical function. I pulled the PCM, ECM or whet ever it is defined as on this particular vehicle. There was some pretty visible corrosion on, maybe 2 or 3 pins, cleaned this up w/dental picks, elect parts cleaner and compressed air. Still no fuel pump. I would literally have to tear this car apart to trace the wire from the fuel pump to the power center. I have a Haynes manual which is for all intents and purposes useless in this instance. If I had a good wiring diagram or just the info to pin it out I might be able to figure it out. I found a Jeep 1993-94 2.5 and 4.0L EFI powertrain Diagnostics factory service manual. Would this manual provide the info. I need to further diagnose this vehicle? Any help would be gratly appreciated. Thanks, John V.
Thursday, June 26th, 2008 AT 10:28 AM