Engine won't turn off with key

Hello all,

I'm having an issue with my XJ (91 sport, 4.0l 5-spd, 4x4). When I turn the key off the engine won't shut off. I have to stall it to get it to and then it acts like the key is still in the on position so I have to disconnect the battery so the battery won't die when its sitting. If you have any ideas, I would appreciate any input you can provide as I will only have a couple of hours on Saturday to diagnose and repair it (darn school taking up all my time already).

Thanks guys

Sounds like ign switch, or short to ground somewhere.

check Auto Shut Down relay. A mechanic advised lightly tapping the relay when it fails to shutdown. If she stops, relay is bad. cost should be $15ish

Agree with both, the ASD and ignition switch are the most likely culprits.

Thanks guys. I was thinking that it would probably be the ign switch as well but I didn't know about the auto shut-down relay. Any other ideas would be greatly appreciated and if anybody could provide me with a location for that relay on a 1991 sport it would be great.

Thanks again

I would suspect the ignition switch. The "off" position would kill the engine by grounding the ignition circuit.

Hello again,

I finally got around to trying to figure this thing out. When I tapped the auto-shutdown relay, nothing happened so I went out and got a new ignition switch. Still nothing. So...... any other ideas? I haven't started checking for shorts yet. Anybody know of any common places that shorts can occur (specifically to do with the ignition system)?

I'll describe what is happening again just incase I left something out before. It started as a sporaddic thing. In fact, it happened for 2 days straight, went away for a couple and then came back a couple different times. Its consistent now though. What happens is that the thing runs great but when I go to turn it off with the key, it won't shut off. If I stall if or disconnect the ballast resistor, the motor stops running but the oil pressure light and the e-brake light on the dash both stay on and as far as I can tell, the fuel pump stays primed until I disconnect the battery.

Thanks for you help. I am kind of in a panic at this point because I am trying to sell it and I have a guy coming to look at it tomorrow.

You tapped the ASD relay? Try swapping them around.

When you pull the wire from the ballast resistor the pump stops--there is only one hot lead for the pump. Not losing its "priming" is a good thing.

joe_peters said:

You tapped the ASD relay? Try swapping them around.

When you pull the wire from the ballast resistor the pump stops--there is only one hot lead for the pump. Not losing its "priming" is a good thing.

Click to expand...

Yup, tapped the ASD relay and it did nothing. I got it figured out though I think. I checked the ignition switch connectors and found that one of the connectors was cracked and I suppose that when it was plugged in it was allowing 2 leads to touch. Works fine now (I cycled the key about 50 times and everything acted like it should). I even adjusted the ignition switch properly so the accessory position on the key works now.

Thanks for your help. Hopefully the guy will buy the heep now.