Engine keeps running!!

Hey I have a problem where the engine keeps running for about 3-5 seconds after I take the key out. I was wondering if this was going to turn into a major problem or if there is a way to get this fixed? THanx

It might help to know what year XJ, what engine, and how many miles are on it.

I have an 88 4.0 non H.O. with 168000 on it.

Are you using crappy gas? Fuel that is too low of an octane will "diesel" or ignite without any spark - this can cause an engine to do what you are describing.

I tend to believe this could be more than bad gas. My new '89 4.0 does the same thing. I'm not talking about what would be refered to as "dieseling" but the engine actually continues running (not sputtering) for long enough to pocket the keys and get out of the vehicle. Mine seems kind of like the ignition is staying hot and the engine runs until it runs out of fuel, I haven't even looked into it yet 'cause it's far from the top of the "to do" list but it's defineately not a bad fuel issue.