Turns won't start

Turns over but won't start. New pump runs but, o
pressure at fuel rail  spark exist but is weak. New
Delphi fuel pump, fuel filter, cap rotor, plugs, wires,
Crank position sensor, cam position sensor, coil,
ignition control module. Have had it in the shop
twice to fix. Both times it was a wire from the brain
box that had shorted. Once it stopped running
while driving, other two times wouldn't start after
sitting overnight.