1995 LAND ROVER DISCOVERY warning

EMISSION CONTROL
1
REPAIR POSITIVE CRANKCASE VENTILATION AIR
INTAKE FILTER
Service repair no - 17.10.02
The PCV air intake filter is located at the rear of the
left hand rocker cover, beneath the throttle linkage
bracket.
Remove
1.Pry the filter outer cover upwards to release it
from its mounting.
2.Remove the sponge filter from the cover and
discard the sponge.
Refit
3.Insert a new filter into the filter cover.
4.Press the filter onto its mounting until it clips
firmly into position.POSITIVE CRANKCASE VENTILATION BREATHER
FILTER
Service repair no - 17.10.03
Remove
1.Release the hose clamp and pull the hose off the
canister.
2.Unscrew the canister and remove it from the
rocker cover.
3.Remove the large rubber 'O' ring and inspect for
deterioration.
4.Visually inspect the condition of the wire screen
within the canister, if in poor condition, replace
the whole assembly, if the filter unit is in an
acceptable condition, clean as follows.
5.Immerse the canister in a small amount of
solvent (mineral spirits) and allow time for the
solvent to dissolve or loosen any debris.
6.Remove the canister from the solvent bath and
allow to dry in still air.
WARNING: Do not use a compressed air
line to dry, clean or remove any remaining
particles of debris within the canister as
this could cause fire or personal injury.
Refit
7.If the original canister is being refitted, fit a new
'O' ring.
8.Screw the canister into the rocker cover securely
- hand tight only.
9.Refit the hose and tighten the hose clamp
securely.

17EMISSION CONTROL
4
REPAIR HEATED OXYGEN SENSOR (HO2S) - 4.0 V8
WARNING: Do not attempt HO2S removal
when the exhaust is hot.
Remove
For all sensors:
1.Raise and support front of vehicle.
2.Release sensor lead from clips.
RH front sensor only
3.Remove nuts retaining coil bracket and position
bracket aside.
See FUEL SYSTEM SFI, Repair,
Ignition Coils
4.Release multiplug from bracket behind cylinder
head.
5.Disconnect multiplug and release sensor lead
from clip.
6.Unscrew and remove sensor from exhaust pipe.LH front sensor
7.Disconnect multiplug and release from bracket.
8.Unscrew and remove sensor from exhaust pipe
using special tool LRT-12-047 (LST134).

17EMISSION CONTROL
6
REPAIR CATALYTIC CONVERTER/FRONT PIPE - 4.0 V8
Service repair no - 17.50.09
WARNING: The removal of the exhaust
system must only be carried out when the
engine is cold.
Remove
1.Disconnect battery negative lead.
2.Raise vehicle on ramp.
3.Remove oxygen sensors
See Heated Oxygen
Sensor (HO2S) - 4.0 V8
4.Remove 4 nuts/bolts securing front anti-roll bar
brackets.
5.Remove 6 nuts securing front pipe flanges to
manifolds.
6.Remove 2 nuts securing front pipe to
intermediate pipe.
7.With assistance, release front pipe from manifold
flanges.8.With assistance, release front pipe from
intermediate pipe.
9.With assistance, lower anti-roll bar.
10.With assistance, remove exhaust front pipe.
11.Remove flange gaskets and discard.
Refit
12.Reverse removal procedure.

19FUEL SYSTEM
4
DESCRIPTION AND OPERATION OPERATION
Diesel engines operate by compression ignition. The
rapid compression of air in the cylinder during the
compression cycle heats the injected fuel, causing it
to self ignite. During cold starting, automatically
controlled glow plugs assist in raising the temperature
of the compressed air to ignition point.
A cold start advance unit advances the injection timing
to further assist starting. Idle quality is improved by
the high idle setting.
The engine is supplied with pre-compressed air by a
single stage turbocharger.
Exhaust gases passing over a turbine cause it to
rotate, driving a compressor mounted on the turbine
shaft. Air drawn from the cold air intake passes, via
the air cleaner, to the turbocharger where it is
compressed. The compressed air passes to the
cylinders via an intercooler, which reduces the
temperature of the compressed air, increasing its
density.
Fuel is drawn from the tank by a mechanical lift pump
and passes to the injection pump via a filter. In
addition to removing particle contamination from the
fuel, the filter incorporates a water separator, which
removes and stores both bound and unbound water.
The injection pump meters a precisely timed, exact
quantity of fuel to the injectors in response to throttle
variations, injection timing varying with engine speed.
Any excess fuel delivered to the injection pump is not
injected, passing back to the tank via the fuel return
line.
Fuel is injected in a finely atomised form into a
pre-combustion chamber in the cylinder head where it
ignites. The burning fuel expands rapidly into the main
combustion chamber, creating extreme turbulence
which mixes the burning fuel thoroughly with the
compressed air, providing complete combustion.
Cold Starting is assisted by glow plugs, a cold start
advance unit and a high idle setting.Glow plugs
Glow plug operation is controlled by a timer unit, start
relay and resistor. When the ignition is turned on the
timer unit is energised, the glow plugs start to operate
and a warning light on the dashboard illuminates,
remaining illuminated until the glow plugs are
automatically switched off.
The length of time the glow plugs will operate is
dependent on under bonnet temperature, which is
monitored by a sensor located in the timer unit.
Starting the engine results in the power supply to the
glow plugs passing through the resistor, which
reduces their operating temperature. The glow plugs
are cut out either by the temperature sensor in the
timer, or by a microswitch on the injection pump which
operates when the throttle is depressed.
Cold start advance
The cold start advance unit is connected to the engine
cooling system via hoses. It contains a temperature
sensitive element which is retracted when cold and
pulls the advance lever, via cable, towards the rear of
the pump against spring pressure. As coolant
temperature rises, the cold start element expands
releasing tension on the cable and allowing spring
pressure to move the advance lever forwards.

Tdi
1
REPAIR TANK SENDER UNIT
Service repair no - 88.25.32
WARNING: Ensure that the WARNINGS
and FUEL HANDLING PRECAUTIONS
given in Section 01 are adhered to before
carrying out the following operations.
Special tool - LST131
Remove
1.Disconnect battery negative lead.
2.Remove the rear carpet retainer.
3.Ease the carpet from under the lower trim panels
at the rear of the fold down seats.
4.Raise the carpet to expose the sound insulation.
5.Fold back the sound insulation to reveal the
access panel.
6.Remove the securing screws and detach the
access panel from the floor.
7.Disconnect the multi-plug from sender unit.8.Disconnect the fuel pipes from the sender unit.
9.Using special tool LST131 remove the locking
ring and withdraw the sender unit from the fuel
tank.
Refit
10.Fit the sender unit to the fuel tank and secure
with the locking ring. Tighten to
45to50 Nm.
11.Connect the fuel pipes to the sender unit.
12.Connect multi-plug to sender unit.
13.Inspect the access panel seal to ensure that it is
satisfactory for further use, renew as necessary.
14.Fit the access panel to the aperture in the floor
and secure with the screws.
15.Reverse removal procedure. 1 to 5. Refit the
sound insulation and carpet.

MFI
3
DESCRIPTION AND OPERATION Tune select resistor -
To suit individual market requirements a tune select
resistor is connected across pins 5 and 27 of the
ECM.
It is located adjacent to the ECM, and strapped to the
MFI cable assembly. The value of the resistor is
dependent on the market application:
Red wire, 180 ohms, Australia, Rest of world.
Green wire, 470 Ohms, UK and Europe - non catalyst.
Yellow wire 910 Ohms, Saudi non catalyst.
White wire, 3K9 Ohms, European catalyst
Condenser fans
It should be noted that under high coolant
temperatures, when the engine is switched off, the
condenser fans will be activated and will run for
approximately ten minutes.Vehicle speed sensor
The vehicle speed sensor is located on the side of the
Transfer box adjacent to the parking brake. The
sensor provides road speed data to the ECM. The
ECM in turn detects vehicle movement from the road
speed input and ensures that idle air control mode is
disengaged. Should the vehicle speed sensor fail in
service the ECM idle air control would become erratic.
The sensor also provides road speed data to the
electric speedometer and cruise control ECU.
Inertia fuel shutoff switch
The inertia fuel shutoff switch is a mechanically
operated switch, located on the bulkhead adjacent to
the washer reservoir under bonnet [hood].
The switch is normally closed and is in line with the
fuel pump. In the event of a sudden impact the switch
opens, and disconnects the electrical feed to the fuel
pump. The switch is reset by pressing down the
button.
WARNING: Check the integrity of the fuel
system before the inertia switch is reset.
Relay modules
The two multiport fuel injection relays are located in
the RH footwell area behind the 'A' post panel. The
main relay module is energized via the ECM when the
ignition is switched on and supplies current to the
multiport fuel injection system. The fuel pump relay
module is energized by the ECM which in turn
operates the fuel pump to pressurize the fuel system.

MFI
3
FAULT DIAGNOSIS FUEL PRESSURE CHECK
In order to check the fuel pressure it is necessary to
first depressurise the fuel system as follows:
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.
A Pressure gauge 18G1500
B Fuel tank and pump
C Fuel filter
D Fuel injectors x 8
E Regulator1.Remove fuel pump relay module.
See Repair,
Multiport Fuel Injection Relay
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 pipe at
the filter during disconnection.
5.Connect the pressure gauge on the outlet from
the filter, located on the chassis under the right
rear wheel arch.
6.Reconnect the battery and turn the ignition to
position II while observing the pressure gauge.
Results
Expected reading 2,39-2,672 kgf/cm
2
Pressure drop-max 0.7 kgf/cm2in one minute.
If pressure is low check that filter is not blocked
and pump is operating satisfactorily. Then
recheck pressure. If pressure is still low renew
regulator.
See Repair, Fuel Pressure
Regulator

19FUEL 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).