Truck hesitates after trying to accelerate

Ok so it will idle like a champ, not throwing any codes up, but chugs when i
try to accelerate.
Things ive replaced:
Cap, Rotor, Spark plugs, crankshaft position sensor, wires, fuel filter, coil,
and the heat shielding around one of the spark plugs (wasnt allowing the
spark plug to be driven all the way into place, pops off the socket)

to me it smells a bit on the rich side, but the plugs werent to terrible, but
needed replaced

i talked to a couple people and they said either the fuel pressure regulator, or
fuel pump. i just want some opinions where i should throw my money first
since this seems to be one hell of a money pit..

thanks for the help