Please help. I have an 89 xj with the 4.0, the jeep starts no problem every time but dies as soon as i let go of the key. I know it's getting fuel because it starts over and over again and runs until the initial rev of me stepping on the gas dies out. Also it will stay running and rev if i hold the key to the start position and keep on the gas. Please, I need help.

replace your ignition switch

If its not your key switch check the fuseable link under the relay cover on the pass side of the engine compartment. Sometimes the link burnsout and the pump willnot run after starting. Pull on the green wires gentley and if one is broken it will strech. This is what was wrong with mine when it did this.

By ignition switch do you mean the actual electrical connector along the steering column or the place i stick my key in to start it? I know the switch is somewhere along the column but with all the crap down there i can't tell whats what. I checked the links along the passenger side of the engine compartment and the wires all look in good shape. I really need to get this thing running as soon and as cheaply as possible.

the switch is located in the lower-end of the stearing column

disconect the neg battery cable

remove the lower dash trim panel

set the key in the off-lock possition

remove the 2 screws holding the switch to the column and disconect the actuating rod

disconect the black conector from the white one

re-install the oposite until you get the screws finger tight

hold the key in the accsory position, and push the switch tward the bottom of the column to remove any slack in the rod, and hold it while you finish tightening the screws

plug back in the conector, put the trim back on and reconect the neg cable

you should be back on the road for less than $15

okay, changed the ignition switch and same problem.....now what?

damn, that was the most likely problem.

next I'd check for bad wiring harness conections @ the ditributor, coil, alternator. unplug and clean them.

also your computer holds no trouble codes but you can get a reader that gives you input for all of the sensors. the only thing that is makeing sense to me (since you replaced the switch) is that when starting the computer may be ignoring 1 or more of your sensors, but when you return the key to the run position it gets an unaceptable reading and shuts down.

both of these are longshots, I really thought the switch would fix you up.

Have you checked to see if the fuel pump runs after it starts or just when your starting.
And Does the pump run for a few seconds when you turn the key on. It sounds like it might be a fuel prolbem if it dies after starting.

I should have listened to you, richpinkham. My buddy and I were shooting wires to the fuel pump when he happened to notice one of the green wires looked a little beat up going into the relays on the passenger side of the hood. We replaced it and it's run fine since. It actually took longer to put my dashboard back together than to fix the real problem. Thanks for your help.

Its hard to give a good diagnoise of a prolbem that can not be seen just from a discription. But glad you got it fixed and it was an easy fix. I have both an 89 cherokee LTD and a 99 Grand cherokee LTD both with the 4.0 six, and have had to fix prolbems with both, but the 99 is supriseingly nicer to drive and gets better mileage.