Fuel Pressure Regulator

Our 20 valve turbo 3B, AAN, ABY and ADU engines have electronic fuel injectors. These injectors are connected to a fuel rail that is pressurized by a two-stage in-tank fuel pump. Since there are many variables to be dealt with, e.g. RPM, load, boost pressure, etc. one way of eliminating some fuel delivery issues is to use a fuel pressure regulator to maintain a "constant" (or close to constant) differential pressure across the fuel injector. (More info regarding our fuel injectors is found here). This constant pressure differential is maintained by a fuel pressure regulator(FPR). In our case, it's a 4 Bar (58 psi) FPR (For the 3B it was 3.0 Bar and for the RS2 3.8 Bar)

The general arrangement of the fuel system and the FPR is shown here: