High Pressure Pump

High Pressure Pump


Fuel system is under high pressure! Before opening the system, perform the procedure for releasing fuel pressure. Refer to => [ Before Opening High Pressure Fuel Injection System ] Service and Repair.

• For safety reasons, if the battery is not disconnected, fuse SC 27 from the fuel pump control module (J538) must be removed before opening the fuel system, otherwise the fuel pump will be activated by the driver's door contact switch.





• By removing fuse SC 27, the voltage supply to terminal 30 for the fuel pump control module is interrupted.

• The removal and installation of the high-pressure fuel pump can only be performed on a cold engine.

• When installing the high-pressure fuel pump, make sure that no dirt enters the fuel system.

• Catch escaping fuel with a rag.

• The O-ring must always be replaced.

• The banjo bolt for the fuel return line (only on high pressure pumps with threaded connection) must always be replaced.

• High-pressure fuel lines must always be fastened free of tension.

Removing

- Remove engine cover. Refer to => [ Engine Cover with Air Filter Element ] Service and Repair.

- Disconnect electrical connectors from low fuel pressure sensor (G410) - 1 - and fuel pressure regulator valve (N276) - 2 -.





- Open both fuel lines at high-pressure pump.

- Connections of the old high pressure pumps:





- Connections of the new high pressure pumps:





- Remove the 3 bolts - arrows -.





- Carefully pull out the high-pressure fuel pump. The valve lifter can remain inserted in cylinder head under some circumstances.

Installing

- Replace high pressure pump O-ring and coat it lightly with clean engine oil.

- Carefully place high pressure pump with the valve lifter in opening in cylinder head (check the valve lifter for damage first).

- Tighten the bolts diagonally to the specified torque. Refer to => [ High Pressure Pump Assembly Overview ] High Pressure Pump Assembly Overview

- Before installing the fuel lines, check the torque of the connections on the high-pressure pump.

• Fuel return line connections tightening specifications, refer to => [ High Pressure Pump Assembly Overview ] High Pressure Pump Assembly Overview.

• Fuel supply line connections tightening specifications, refer to => [ High Pressure Pump Assembly Overview ] High Pressure Pump Assembly Overview.

• If the fuel return line was secured with a banjo bolt, replace the banjo bolt for the fuel return line.

• If the fuel return line is a hose, secure the connection with a hose clamp.

- Tighten the new banjo bolt for the fuel return line hand-tight. Align so it is free of stress.

- Tighten the fuel supply line union nut by hand. Align so it is free of stress.

• Tightening specification for the fuel return line (new banjo bolt), refer to => [ High Pressure Pump Assembly Overview ] High Pressure Pump Assembly Overview.

• Fuel supply line (union nut) tightening specifications, refer to => [ High Pressure Pump Assembly Overview ] High Pressure Pump Assembly Overview.

- Connect electrical connectors on low fuel pressure sensor and for fuel pressure regulator valve.





- Re-insert fuse if it was removed.

• Check fuel system for leaks.