I have a 94 Chevy 3500 with a 6.5 diesel. It has new injectors and glow plugs. I moved the pmd to the bumper. The problem is that the throttle doesn't do anything after about 1/2 to 3/4 throttle. The truck struggles to do anything over 50 mph. It wants to Spit and spuder once the rpms do build up. Any suggestions ? I can't think of anything but bad injection pump

 

What's left besides injection pump, lift pump, or boost leaks? What's the boost look like? Do you have a fuel pressure gauge?

 

What wildcat said

 

PPS(Pedal Position Sensor)?????

 

Have you checked for trouble codes?
Have you changed the fuel filter recently?
Plugged last ditch screen in filter manager?
plugged screens in IP fuel inlet?
Plugged fuel strainer sock in the tank?
Plugged vent in fuel filler cap?-excessive suction when filler cap is removed?
Air filter condition?
Lift pump working?
Collapsed exhaust crossover?
Plugged soot trap?