car dies while driving, sits for a bit and restarts

What is your question?

car starts ok in the morn. but after driving for apx. 30 min it cuts out n dies, cranks n has full power but no grip, i let it sit for 20 to 45 min (progressively getting worse) and it starts. replaced plugs, wires, dist cap, rotor, cam seal, crank seal, fuel filter, timing belt n tensioner pulley, $1500.00 later it did the same darn thing so i dot know... maybe coil or fuel pump not too sure plz help...