I have a 1988 Jeep cherekee pioneer with a 4.0L motor in it. My issue is the engine will run fine when the starter is engaged but quits when I return the key to the run position. I have replaced the ignition switch and the ceramic fuel pump ballist and still I have the problem. :banghead: any ONE HAVE an idea?

Test the ignition switch.

If you've replaced the ign switch at the bottom of the steering column, you may not have it adjusted correctly. If you did the key lock, that's not the switch.

In either case, as AlohaBra, you should test the circuits at the switch to make sure it's working OK. Wouldn't be the first time a new part went bad.

Was it doing this before the switch swap?

I have changed the ignition switch and it is adjusted correctly. This was the reason I changed the switch.

I have found that the fuel pump has power only while the key is in the start position. As soon as the key goes to the run position I loose power to the fuel pump.

Auto shutdown relay or B+ Latch Relay.

http://www.automotiveforums.com/vbulletin/showthread.php?t=662056&highlight=B+Latch


I will assume you are getting 12 volts from pin 11 of the ignition switch (Yellow). Please check this.

http://jeep.larrynova.com/88/Ignition_wiring_Diagram.pdf

power to #11 when the key is in the start and run position.

I have traced the orange\black wire back to the starter relay. I can get the jeep to stay running by hooking a jumper wire from the positive post of the battery and to the orange/black wire on the starter relay. I have power to the fuel pump when doing this. The jeep runs great with this jumper wire hooked up. I am at a loss of what I am actually bypassing? Is the fuel pump relay or is there some other switch that I am missing?

It's ALIVE. Thanks for help Alohabra. I was checking the b+ relay and found no power to the supply of the relay. The relay would work but no power transfering. I traced the wire back and found the break under the coolant tank by fire wall. Hook all four wires together and WALA. You put me in the correct direction Thanks again.

Good work, that ones sounded difficult to trace indeed.