Last fall on a wet morning I was driving on the interstate when my 1991 xj 40 just died. It started back up and I took it home. It stumbled a few times on the way. I had a few problems later with the battery going dead and the trunk not locking (Probably not related) The tach also jumps around sometimes.I had a new cap and rotor and wires installedand put the car away for the winter. Last weekI took it out and went for a drive. Again it died. We checked the wires and the one tothe coil had come out.I installed a new coil thinking it may solve the problem. Took it out today, drove to the gas station, filled it up and then it would not start. Waited for about an hour and it started up. I drove it to my mechanic and left it with him. He is a very goodmechanic, and works on a lot of exotic cars,but heis puzzled.

This is a second car that I like to drive in the warmer weather. It ran like a top from July when I bought it until November when it started giving me fits.

Any thoughts?

 

That's pretty much what's been happening to my 91 Cherokee lately too. It was a California car that I just bought and over the last week or two it just completely turned itself off while I was leaving my driveway, and twice in a mall parking lot. And prior to that I had a hell ofa time getting it started one cold morning. It would turnover and then not stay on when you let go of the key. She's only got 60K miles on it and I think I'll be going back to my mechanic and do the recommended tune up like you did with your Jag. The only other thing I can think of thats going on and possibly with your Jag is the alternator?? Considering that is the power for just about everything since I noticed my lights vibe in and out dimming when I started it this morning. I'd start with testing your alternator cuz you dont want to go replacing random expensive parts when they dont neccessarily need to be replaced like I've done a couple times on my 93 XJ40. How many miles does yours have on it anyways?? Hope this helps a little. But like I said my Jeep is going back to my mechanic soon and if it seems to be a related problem I'll update you!!

 

My XJ12 also stopped suddenly while on the highway while it was running marvelous, but I could not get it started even after a few days.
My mechanic did manage to start it after changing the cranck sensor, ignition coils and all three belts. It started right away for a week or two but now is back to the condition when I bought the car (couple of tries to start).
You certainly got yourself a jag ... I am trying to sell mine, not because of cost, but because no one around wants to work on it and no one is able to fix it.

Ignition and fuel systems ....