Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: jeepjones on February 09, 2008, 12:52:57 AM

Title: No power to fuel pump, but pump tested ok
Post by: jeepjones on February 09, 2008, 12:52:57 AM

The '98 TJ has got Gremlins! Heres the problem: plenty of spark, turns over fine, battery is good, fuel pump is good (removed and tested), but there is no power to the fuel pump at the connector. Three days ago I replaced the cap, rotor,plugs and wires. Jeep ran fine, then out of the blue I started it up and it Stalled! It's the first time this has happened, Fuel pump relay has checked out fine. After it stalled it would not start back up right away, but it would eventually start after turning ignition on and off about 5 times, until Friday morning. Jeep started and ran for about 20 seconds and then died and refused to start again. The PCM is not throwing out any codes and no check engine/gauges lights have activated. Has anyone ever experienced anything like this?

Title: Re: No power to fuel pump, but pump tested ok
Post by: Bnine on February 09, 2008, 10:22:04 AM

Bad wire in the harness to the feul sendin unit. Bad relay. Bad fuse. Start checking those.

Title: Re: No power to fuel pump, but pump tested ok
Post by: Rookie on February 09, 2008, 12:32:07 PM

Crank position sensor

Title: Re: No power to fuel pump, but pump tested ok
Post by: jeepjones on February 09, 2008, 05:04:25 PM

Well guys after a bunch of testing it turns out that the CPU is fried, thats why no codes were present. We bypassed the CPU and the jeep runs. Guess the TJ is getting a new CPU, anyone know a good place to get a good price on one? I got a computer for the Jeep from Ken at JEEPSTUFF the TJ is now back on the road. Thank you Ken.