Fuel Pressure Sensor: Service and Repair
WM 240919 Removing and installing fuel pressure sensor
Tools
Technical values
Preliminary work
1. Remove left engine compartment cover. For details, see -> 700219 Removing and installing front trim (engine compartment) - section on "Removing"
2. Pull the fuse for the fuel pump out of the slot in the central electrical system or disconnect the battery. This prevents the fuel pump from starting when a door is opened.
Removing fuel pressure sensor
Removing high-pressure sensor (rail pressure sensor)
WARNING
Toxic substances
- Danger of poisoning or suffocation
-> Ventilate the work area well.
-> Never ingest or inhale.
-> Read specific information on the Hazard Sheet.
-> Wear personal protective gear.
WARNING
Highly inflammable or explosive materials
- Danger of fire or explosion
-> Avoid contact with hot parts or sources of ignition.
-> Use suction to remove ignitable vapours.
-> Attach warning sign in a clearly visible position.
NOTICE
Dirt on injection system components (intake manifold injection and direct fuel injection system)
- Material damage
- Rough-running engine
- Bad exhaust emissions
-> Thoroughly clean connection points and adjacent areas before loosening them. If the engine is very dirty, wash it before starting disassembly work.
-> Lay removed parts on a clean surface and cover them. Do not use fibre-shedding cloths.
-> Carefully cover components or seal them if repair work will not be carried out immediately. Place rubber caps on connections. Seal intake openings with film or adhesive tape.
-> Only install clean parts. Do not take spare parts out of the packaging until just before installation.
-> Never use compressed air when the system is open. Do not move the vehicle.
WARNING
Leaking fuel supply lines
- Emerging fuel
- Risk of fire
-> Perform leak test.
Information
- Do not bend high-pressure lines. Always remove the high-pressure distributor pipe and other fuel-supply components in the high-pressure area completely. Check that the connection points are not damaged and are perfectly clean and make sure there is no thread damage. Fit union nuts on all connection points by hand before screwing in screws or bolts. Remove dirt on the conical/ball joints. Check connection points for leaks following fitting.
Information
- The ignition must be switched off when working on the fuel system.
- Absorb any escaping fuel using a suitable binding material or a cloth.
- Cloths which have absorbed fuel must be disposed of according to the applicable national laws.
- The fuel system must be depressurised before starting work on it.
- Only work on the fuel system in well-ventilated rooms.
- Any seals which have been removed must always be replaced.
1. Remove cable plug for the high-pressure sensor -3-.
View of threaded connections in high-pressure system
2. Place a cloth under the high-pressure sensor and remove the high-pressure sensor slowly using a long socket (e.g. Hazet 900 Lg socket-wrench insert Nr.188 or a similar tool). Relieve the fuel pressure by slowly opening the high-pressure sensor.
3. Visually check the thread and sealing ball to make sure they are not damaged.
Installing
Installing high-pressure sensor (rail pressure sensor)
1. Visually check the thread and sealing ball to make sure they are not damaged.
2. It must be possible to turn the high-pressure sensor slightly by hand. Lightly lubricate the high-pressure sensor with engine oil.
3. Screw on the high-pressure sensor using a long socket (e.g. Hazet 900 Lg socket-wrench insert Nr.188 or a similar tool) -3-. => Tightening torque: 22 Nm (16 ftlb.)
View of threaded connections in high-pressure system
4. Connect cable plug for high-pressure sensor.
5. Check high-pressure distributor pipe for leaks. Following a test drive, visually inspect the high-pressure sensor with a mirror and lamp at idle speed.
Subsequent work
1. Fit the fuse for the fuel pump or connect the battery.
2. Fit engine compartment cover. For details, see -> 700219 Removing and installing front trim (engine compartment) - section on "Installing"