Xj starts then dies a couple seconds later

starts fine but dies it doesnt doo it all the time acts like fuel is shut off bc it doesnt stumble it just dies like i shut off the key
have changed map with a known good and still does it

Mine did this a few years ago. While driving down the road it would suddenly die, I would have to quickly put it into neutral and fire it back up. It didn't do it all the time, but would really make me mad, just going down the road and all of a sudden it would just shut off like I turned the key off.

Mine was the crank shaft sensor

Hope this helps

You ever figure out what was going on??

theres a ballast resistor for the fuel pump i tihnk it is that goin bad but i have to wait for it to act up again to make sure