When a friends 99.5 powerstroke went bad, a few guys tried to diagnosis it. After giving up, a friend asked the head of the Diesel Power program at the local community college, and he said it was probably the lift pump in the fuel tank. But he also said that the HEUI's dont have a fuel pump other than the lift pump in the tank- they are a low pressure fuel system. I always had the understanding there was an actual fuel pump on the motor to up the fuel pressure going to the injectors, but now i'm lost. I feel like an idiot asking, but can someone explain how the fuel system on the powerstroke works? Thanks

 

Fuel pump is on the engin between the turbo and fulel filter on my truck. This should explain things. http://www.forddoctorsdts.com/public...d%20Diesel.pdf see page 42 and 43.

 

The super duties have an electric fuel pump on the frame rail. No pump in the tank or on the engine. They run pressures in the 50-70 psi mark. But testing fuel pressure is hard to do as you either have to remove the 1/8 inch pipe plugs at the front of the passenger head or the rear of the driver side head. Or you need to get an adapter for a fitting on the filter housing.