1996 Grand Voyager

140K miles on a 3.3ltr.

on occation all guages quit at once while driving. Once the van is stopped and parked and you try starting it again, the engine will start only for 2 to 3 seconds and die! After a few hours, the guages begin working again and it starts up and drives fine. I've changed alternator, battery, had mechanic check all wire connections for shorts and spent 400 hundred dollars for a rebuilt computer that was programed before I had it installed last week. Was running fine for 1 week and started the same problem today. Any idea?