7.3L Power Loss after Warm.

[BOS811]

I got a stock 7.3 (as for as I know) in a 2002 F-250. I had a problem where it would die and not start back up for awhile. Had the local Ford dealer look at it. They ended up replacing the computer. Now, after driving it for 40 miles straight the engine will lose all power. The lights on the dash come onand the truck will not go. The engine is still running. I remove my foot from the fuel pedal and wait a few seconds and the truck goes back to running fine. The fequency at which this happens changes. In fact, there is an off ramp I take on my way home that has a speed bump. Everytime, I hit that speed bump the truck turns off completely. However, does not do it with bumps in the road. Does anyone have any ideas? I have spent $3000.00 at the local dealership and I am still having this problem. Looking for someone who has a clue since this dealership does not.
Thanks,
Bos

I know I am new here but can someone help please.