Fuel Pressure Regulators

An FPR works by bleeding off a portion of the fuel flow to the injectors from the fuel pump to control the fuel pressure. Fuel is pumped from the fuel tank to the fuel rail by the fuel pump. The FPR is normally mounted after the fuel rail. This ensures that the fuel rail has priority in fuel flow. The valve in the FPR controls the amount of fuel that is bled from the fuel rail by opening an outlet port. This allows fuel to flow back into the fuel tank.