Engine quit running then wouldn't restart?

I'm gonna see if I can get it up to a shop and run it for codes. I've don everything I can think of doing. Thanks for all your help.

This has been a major headache! Truck will turn over like it wants to crank but no fire/then no fuel.
My mechanics are great knowledgable guys - thought first to be the coil, (did not put in) then put in the ignition modular, run great for a couple of days. Then lost all power. Finally cranked back - got to work - end of day - nothing again - hooked computer to determine problem. Ecm was determined to be the problem. AGAIN. Fixed the problem (temporary!) Died again. Last resort - the coil was put in, at present time truck is running. Any thoughts? Everyone is baffled? Engine is new. Only approx 30,000 on new engine. Tonight a major tune up is going to be done. Time for one anyway. Single mom and needs this truck, son's in rodeo. Any advise will be greatly appreciated! Leaving out and not knowing is scary!

An inition modular, coil and an ecm has been put on but occasional it keeps cutting off. It will turn over but not fire. You can hear the fuel pump humming.
All the fuses have been checked. When it quits it could be sitting in the driveway or driving down the road. I lose all power driving down the road. ( Not the stereo, lights etc just speed) Then it will roll over but not crank. It does it hot or cold doesn't matter.
Last time it did it in the parking lot at work. Went out at lunch to go get gas. Would not crank. Roll back took it to a friend of mine's house - drove off the roll back and ran for a week. Everyone is confused. Any ideas would be appreciated!

That's the only way I can keep it running. My friend suggests the computer, and another suggests the fuel pump. I put the truck on a diag and it showed no codes other than 12. I don't have a fuel pressure port, but I'm going to try to rig one up for where the fuel line connects to the fuel filter.

I checked the fuel pressure and it's reading at 8. My book says 9-13psi. Makes me think it's not the fuel pump.

I just decided to go with replacing the fuel pump and it worked just fine. When I took out the pump, it was the original pump that came with the truck. It was 15 years old, I can imagine that's why I was having trouble. I really do appreciate all your help though. I can tell you know what you're talking about, so if I ever have more question I'll come to you.