'91 XJ 4x4 with a 4.0 and a 5 spd. pretty much stock with about 133K miles. The truck runs fine, but now it's starting to randomly shut off for no apparent reason. I checked the codes and it doesn't have any stored and I replaced the CPS last week and that has not changed anything. Temperature, speed, RPM, and the fuel level seem to have no effect in when or why it will shut off. It will usually just restart, but it may die in spurts like 4-6 times in a few minutes then it may run for an hour or so with no incidents. It seems like it's losing all electrical power because I notice that the engine RPM's go to about 2K when I restart it like the IAC motor has been reset when the motor is first started. I'm going to take a good look at the ignition coil connections and try to find out if there is a relay that supplies power/ground to the PCM. Any other ideas on where to look???