High Pressure Fuel System

After the filtered fuel leaves the secondary fuel filter it flows to the high pressure fuel injection pump. The high pressure fuel injection pump is gear driven by the camshaft gear and is located at the front of the engine. For additional information on the high pressure fuel injection pump, refer to the HIGH PRESSURE FUEL INJECTION PUMP  in this service information. The high pressure fuel injection pump increases the fuel pressure and delivers fuel to the fuel rails through 2 high pressure lines, 1 per bank. The system pressure generated by the high pressure fuel injection pump is constantly adjusted by the PCM for every operational condition. However, due to the storage volume of the fuel rails, the injection pressure remains constant over the duration of the injection process. Each fuel rail is connected to 4 fuel injectors through individual high pressure pipes. The fuel injectors are controlled by the PCM and are capable of delivering precise fuel quantity based on the operational demands. The fuel injectors are operated in 3 stages: fill stage, main injection stage and end of main injection stage. The fill stage reduces the combustion noise, mechanical load and exhaust emissions. For additional information on fuel injector operation, refer to the FUEL INJECTOR OPERATION  in this service information. The high pressure pump also delivers fuel to the fuel cooler. For additional information, refer to FUEL COOLER  in this service information.

High Pressure Fuel System 

Fig 1: High Pressure Fuel - System Diagram