Depressurising Fuel System on 300Tdi Discovery 19: MFI Repair
19
FUEL SYSTEM
6
REPAIR
ENGINE COOLANT TEMPERATURE SENSOR
Service repair no - 19.22.18
Remove
1. Position drain tray to collect coolant spillage.
2. Disconnect multiplug from coolant sensor.
3. Remove sensor from thermostat housing.
4. Remove and discard copper washer.
Refit
5. Fit a new copper washer.
6. Fit sensor and tigten securely.
7. Top-up cooling system.
8. Run engine, check for water leaks around
sensor.
DEPRESSURISING FUEL SYSTEM
WARNING: Under normal operating
conditions the Multiport fuel injection
system is pressurised by a high pressure
fuel pump, operating at up to 2.3 to 2.5 bar When
engine is stationary pressure is maintained within
system. To prevent pressurised fuel escaping and
to avoid personal injury it is necessary to
depressurise multiport fuel injection system
before any service operations are carried out.
If vehicle has not been run there will be a small
amount of residual pressure in fuel line. The
depressurising procedure must still be carried out
before disconnecting any component within the
fuel system.
The spilling of fuel is unavoidable during this
operation. Ensure that all necessary precautions
are taken to prevent fire and explosion.
1. Remove fuel pump relay module.
See
Multiport Fuel Injection Relays
2. Start and run engine.
3. When sufficient fuel has been used to cause fuel
line pressure to drop, injectors will become
inoperative, resulting in engine stall. Switch off
ignition.
4. Disconnect battery negative lead.
NOTE: Fuel at low pressure will remain in
system. To remove low pressure fuel,
place absorbent cloth around fuel feed
hose at fuel rail.
5. Disconnect either:
a) Nut and olive at fuel rail
OR
b) Hose at inlet end of fuel filter.
Refit
6. Refit fuel feed hose.
7. Refit fuel pump relay module, reconnect battery.
8. Crank engine (engine will fire in approximately 6
to 8 seconds).
