trouble with my superduty

hi i am a first timer so i am new to this i have a 1989 ford superduty with a 460 engine and i beleive i am having a fuel problem sometimes it seems like its starving for gas and sometimes it runs fine i barely have any power going up hills i replaced the plugs cap rotor dist. both fuel pumps and filter and i replaced the spark plug wires when i replaced the fuel pumps it idled much better than before i only had the truck for three weeks and now i am tired of it i even put in the shop for daig. and only came up with fuel pressure to low thats when i put in the new pumps what do i do now:banghead: