High Pressure Fuel Pump

The tank or supply pump moves fuel to the engine's supply circuit. In a direct-injection system, the high-pressure pump raises pressure for the fuel rail and injectors; the two stages have different jobs.

Some direct-injection pumps are driven mechanically by the engine camshaft while an electrically controlled valve regulates fuel delivery. GM describes that arrangement on a specific engine, so the drive design should be checked for the vehicle.

A restricted filter, supply-pump fault or wiring issue can reduce fuel reaching the high-pressure pump. Delphi identifies these as possible low-pressure feed problems in a specific diesel system; test the vehicle's supply circuit before replacing the high-pressure unit.

A paired package fits particular engine configurations. One listed BMW V8 set specifies driver- and passenger-side pumps; other listings contain one pump.

Package contents vary. The listed BMW two-pump set specifies that a gasket or seal is not included, so obtain the required sealing parts according to the vehicle's procedure.