Overview - Fuel System (Through Fall 2009)
WARNING: This page is about a different variant/trim than selected.
WARNING:
- Follow the guidelines for a clean working environment when working on the fuel system. Refer to CLEAN WORKING CONDITIONS AND FUEL SYSTEM WORK INSTRUCTIONS .
- Always follow these rules before and during work.
CAUTION:
Follow the points below to avoid running the high pressure fuel pump dry (very low tolerances) and to start the engine quickly after replacing the components:
- If fuel system components between the fuel tank and high pressure fuel pump were removed or replaced, the fuel system must be bled. Refer to FUEL SYSTEM BLEEDING .
- It is necessary to bleed the fuel system before starting the engine for the first time if the fuel pump, the fuel line (between the fuel tank and the high pressure fuel pump) or the fuel filter were removed.
- If the high pressure fuel pump was removed or replaced, then bleed the fuel system before starting the engine for the first time.
Fill the fuel tank after installing the high pressure pump. Refer to FUEL TANK, FILLING WITH FUEL AFTER INSTALLING HIGH PRESSURE PUMP .
NOTE:
If these instructions are not followed, the high pressure pump will be damaged during the first filling.
- Fuel Metering Valve -N290-
- Do not open
- High Pressure Pump
- After replacing, the fuel tank "must" be filled (never run dry). Refer to FUEL TANK, FILLING WITH FUEL AFTER INSTALLING HIGH PRESSURE PUMP
- The adaptation values must be adapted after replacing the high pressure pump or the Fuel Pressure Regulator Valve -N276-. Refer to "Guided Functions" using the Vehicle Diagnostic Tester.
- High pressure pump overview. Refer to OVERVIEW - HIGH PRESSURE PUMP .
- Removing and installing. Refer to HIGH PRESSURE PUMP, REMOVING AND INSTALLING .
- Fuel Rail
- Cylinder bank 1
- Fuel Pressure Regulator Valve -N276-
- On cylinder bank 1
- Cannot be used again
- The adaptation values must be adapted after replacing the high pressure pump or the Fuel Pressure Regulator Valve -N276-. Refer to "Guided Functions" using the Vehicle Diagnostic Tester.
- Removing and installing. Refer to Fuel Pressure Regulator Valve -N276-, REMOVING AND INSTALLING .
- Fuel Pressure Sensor -G247-
- On cylinder bank 2
- Cannot be used again
- Removing and installing. Refer to Fuel Pressure Sensor -G247-, REMOVING AND INSTALLING .
- Fuel Rail
- For cylinder bank 2
- Injector
- Removing and installing. Refer to PIEZOELECTRIC FUEL INJECTORS, REMOVING AND INSTALLING .
- Fuel Return Lines
- Do not disassemble the fuel return lines. Replace them completely with the pressure retention valve.
- Bleed the fuel system after replacing. Refer to FUEL TANK, FILLING WITH FUEL AFTER INSTALLING HIGH PRESSURE PUMP
- Pressure Retention Valve
- The check valve always maintains a residual pressure (control quantity) of approximately 10 bar (145 psi) in the fuel return lines.
- The Piezoelectric injectors need this control quantity for their function.
- The check valve can be replaced only with the complete fuel return lines.
- Bleed the fuel system after replacing. Refer to FUEL TANK, FILLING WITH FUEL AFTER INSTALLING HIGH PRESSURE PUMP
- Check pressure retaining valve. Refer to FUEL RETURN CHECK VALVE, CHECKING
- Fuel Tank
- With Transfer Fuel Pump -G6-
- Fuel Filter
- Fuel filter overview. Refer to FUEL FILTER
- Fuel filter, replacing. Refer to FUEL FILTER
- Auxiliary Fuel Pump -V393-
- The Auxiliary Fuel Pump -V393- is discontinued starting with MY 2011.