Fuel System Components Overview
WARNING:
- Follow the guidelines for a clean working environment when working on the fuel system. Refer to CLEAN WORKING CONDITIONS .
- Always follow these rules before and during work.
Follow the points below to avoid running the high pressure fuel pump dry and to start the engine quickly after replacing the components:
- It is necessary to perform the "check the transfer fuel pump" basic setting >>once << to bleed the fuel system before starting the engine for the first time if the fuel pump, a fuel line or the fuel filter was removed.
- The "check the transfer fuel pump" basic setting must be performed >>three times<< for bleeding the fuel system before starting the engine for the first time if the fuel high pressure pump was removed or replaced.
CAUTION:
Maintain clean working conditions. Dirt and contaminants must not get into the return lines and the connections on the fuel injectors.
Always protect any opened fuel connections to prevent dirt from getting into them.
- Protective Strip
- For the fuel rail and high pressure lines.
- Fuel Return Lines
- With the pressure retention valve.
- Checking the pressure retention valve. Refer to PRESSURE RETENTION VALVE IN FUEL RETURN LINE, CHECKING .
- Pay attention to the different installation stages. Refer to Fig 3.
- Bolt/Nut
- 8 Nm
- Allocation, refer to Fig 4.
- Fuel Return Line
- Blue or with a blue mark.
- Make sure it is secure.
- To the fuel filter.
- High Pressure Lines
- 28 Nm
- Between the fuel rail and the fuel injectors.CAUTION:
The high pressure lines can be reused only after the following checks:
- Check the sealing cone on each high pressure line for damage and deformation.
- The bore in the line must not be deformed or narrowed.
- Do not use corroded lines again.
- Install without tension, refer to HIGH PRESSURE LINES, INSTALLING .
- Fuel Pressure Regulator Valve -N276-
- 80 Nm
- Checking, refer to FUEL PRESSURE REGULATOR VALVE, CHECKING .
- Removing and installing, refer to Fuel Pressure Regulator Valve -N276- .
- Fuel Rail (High Pressure Reservoir)
- Fuel Temperature Sensor -G81-
- Fuel Supply Line
- Make sure it is secure.
- Between the fuel temperature sensor and the high pressure pump.
- High Pressure Pump
- Removing and installing, refer to HIGH PRESSURE PUMP .
- Tightening specification for the toothed belt gear, refer to TOOTHED BELT DRIVE OVERVIEW .
- Bolt
- 20 Nm
- Tighten the long bolts an additional 180° (1/2) turn.
- Tighten the short bolts an additional 45° (1/8) turn.
- Always replace.
- Bracket
- For the fuel temperature sensor.
- Fuel Supply Line
- White or with a white mark.
- Make sure it is secure.
- From the auxiliary fuel pump -V393- or fuel pump 2 -V277-.
- Fuel Pressure Sensor -G247-
- 100 Nm
- Removing and installing, refer to Fuel Pressure Sensor -G247- .
- Bolt
- 22 Nm
- Tensioning Plate
- Always replace.
- Note the installed position, refer to Fig 2.
- Nut
- 10 Nm
- Sealing Cap
- Bolt
- 5 Nm
- Fuel Injector (Piezo Injector)
- Removing and installing, refer to FUEL INJECTOR .
- The following parts and seals or O-rings must be replaced during each removal or installation, or when a fuel injector is being replaced: "Copper washer", "injector shaft O-ring", "injector return O-ring"
- Install any removed injectors back into their original location (cylinder).
- Visually check the sealing cones before reusing the "fuel injector high pressure line" again.
- Check the sealing cone on each high pressure line for damage and deformation.
- The bore in the line must not be deformed or narrowed.
- Do not reuse corroded lines again.
- High Pressure Line
- 28 Nm
- Between the high pressure pump and the fuel rail.
-A-, no ribbing: Secure the return fuel line
-B-, with ribbing: DO NOT use a clamp to connect the overflow oil line.