1994 Suburban Cuts out and won't start

Alright everyone, lets see if you can help me out with this. I have a 1994 Suburban 5.7L 350 TBI. When driving for no reason the car cuts off. The only lights on the dash are the check gauges light and the battery light. The truck will not restart if you shut if off and try to start it up. I did a full tune up on it and vroom, started right up. Drove three blocks and when i stopped at the stop sign the truck cut out again. I had the ignition module tested (passed the test 6 times) and reinstalled it. Vroom, started up again, i put it in the driveway and put it in reverse and drive in the driveway a couple times and boom..cuts out again! It's not my truck so i wasn't there when it did this the first time but im running out of ideas. I tuned it up, i tested the module, i replaced the coil and nothing. Three months ago i replaced the fuel pump and filter but that wouldn't cut my truck off like that. It cuts off anytime, no real idea on what sets it off. Its got new plugs, wires, cap, rotor, oil, coil, and PCV valve. I was wondering if it was my ignition pick up coil but im getting no fire to the injectors OR spark. The car cranks it just doesn't start so i wouldn't think it to be the Ignition switch. Am i dealing with a computer problem? Possibly a weak engine ground? If anyone has had this problem please help me out. Sorry its so long lol. Thanks again.