The Volume Control Valve (VCV) controls how much fuel enters the two high pressure pump pistons. The high pressure fuel pump is restricted as required by the PCM. Under varying conditions the fuel system is in PCV or VCV mode.
Two high pressure fuel lines from the high pressure fuel pump transport the fuel to the diverter volume area of the left
(driverโs side) fuel rail. From the diverter volume area, fuel goes through an orifice to supply the left fuel rail and through a high pressure fuel line over to the right fuel rail.
Excess fuel from the high pressure fuel pump is routed back to the DFCM/fuel tank. The left fuel rail supplies fuel to the 4 injectors in the left cylinder head via high pressure fuel lines and it supplies fuel to the right side fuel rail via another high pressure fuel line.
The left side fuel rail contains the Pressure Control Valve (PCV) mounted in the rear of the fuel rail and the Fuel Rail
Pressure (FRP) sensor in the front of the fuel rail The PCV regulates the pressure in the fuel rails under specific operating conditions. When operating in PCV mode, fuel released by the PCV is returned to the DFCM/fuel tank.
The high pressure fuel pump is capable of producing up to 199,948 kPa (29,000 psi) to the fuel injectors.
Each fuel rail has 4 individual high pressure fuel lines to supply fuel to the injectors. Injector return fuel is directed back to the low pressure line supplying the secondary fuel filter. The injector return line assembly contains a single throttle (orifice) to generate back flow for proper injector operation. Fuel being directed back to the DFCM/fuel tank goes through the fuel cooler first then to the DFCM.
