I replaced my engine about two months ago. Everything has been perfect until about a week ago. I shut the truck off pull the key out and the engine stays running. It's not dielseling it just keeps running smooth as ever. Sometimes I have to pull a plug out of the computer to get it to shut off other times I just turn the key on and off a bunch of times. Any ideas? I was thinking ignition cylinder but don't want to replace it without some opinions. The engine is out of a 1999 xj 4.0. Direct swap.

 

My girl friend just had the same problem on her car and it was the ignition switch.