Its been awhile since Ive been here, had to do the 13 month thing in Baghdad, move across the country again.... and I found myself going through old stuff and found my login ID......anyway technology keeps evolving and i am wondering which Injector Pump is in my truck. I have a 03 250hp. Is it the VP44 or the CP3?

Whats the difference?

Thanks

Smitty

 

You have CP3 in your truck.The fuel injection pump supplies high pressure to the fuel rail independent of engine speed. This high pressure is then accumulated in the fuel rail. High pressure fuel is constantly supplied to the injectors by the fuel rail. The Engine Control Module (ECM) controls the fueling and timing of the engine by actuating the injectors.

Fuel enters the system from the electric fuel transfer (lift) pump, which is attached to the fuel filter assembly. Fuel is forced through the fuel filter element and then enters the Fuel Pump/Gear Pump, which is attached to the rear of the fuel injection pump. The Fuel Pump/Gear Pump is a low-pressure pump and produce pressures ranging from 551.5 kpa (80 psi) to 1241 kpa (180) psi. Fuel then enters the fuel injection pump. Low pressure fuel is then supplied to the FCA (Fuel Control Actuator).

The FCA is an electronically controlled solenoid valve. The ECM controls the amount of fuel that enters the high-pressure pumping chambers by opening and closing the FCA based on a demanded fuel pressure. The FPS (Fuel Pressure Sensor) on the fuel rail provides the actual fuel pressure. When the actuator is opened, the maximum amount of fuel is being supplied to the fuel injection pump. Any fuel that does not enter the injection pump is directed to the cascade overflow valve. The cascade overflow valve regulates how much excess fuel is used for lubrication of the pump and how much is returned to the tank through the drain manifold.

Fuel entering the injection pump is pressurized to between 300-1600 bar (4351-23206 psi) by three radial pumping chambers. The pressurized fuel is then supplied to the fuel rail. Never crack a line to bleed fuel system on a common rail, fuel pressure will go to max pressure and if injected into skin can cause death. So be safe and don't ever work on high pressure system with engine running. Welcome back home.

 

Big Iron 70,
Now thats a response....thanks man. I have had the lift pump moved to the tank by the dealer, but was curious about the Injection Pump, read a lot of horror stories about the 44 and letting them run with a failed lift pump.

Sounds like the HEUI pump or something like that on the Cat engines we use, with the way it pressures the fuel way high. Yeah I wont open the line on the rail, (great advice).

Thanks Again
Smitty