I have somewhat of the same problem, with my 1993 dodge ram van (5.2 v8)
I was told that it was my ecu or engine control unit. it causes the car to stall and not start up at random times, if the unit is bad. good luck on your problem!!!
I have a 98 jeep 4.0 Cherpkee that when am on the highway for 3 miles going pass 70mph its stalling. It truns back on after 15min.When on the street or going less than 70mph it does not happan. I took it to the shop 2 times and they cant find out what wrong. ANY SUGGESTIONS SEND IT MY WAY!! THANKS!!