1995 LAND ROVER DISCOVERY fuel

Tdi
11
REPAIR FUEL INJECTION PUMP AND TIMING
Service repair no - 19.30.07
NOTE: The following text refers to a Tdi
vehicle with a manual gearbox without
electronic diesel control. Where reference
is made to the timing tool substitute the following
information for automatic and EDC variants.
If manual gearbox:Timing tool LRT-12-044 fits into
the base of the flywheel housing
If manual gearbox with EDC:Timing tool
LRT-12-085 must be used and also fits into the base
of the flywheel housing.
If automatic gearbox:Timing tool LRT-12-044 fits
into the larger bolt hole of coverplate on engine
backplate, sited near to the rear of sump. Pin locates
in ring gear.
Remove
1.Disconnect battery negative lead.
2.Remove injection pipes, pump to injector.
3.Remove oil filler cap from rocker cover.
4.Viewing valve mechanism through filler aperture,
turn crankshaft clockwise until No. 1 cylinder is
just before TDC.
5.Refit oil filler cap.
6.Remove blanking plug from flywheel housing.
7.Fit timing tool LRT-12-044 to flywheel housing,
do not engage centre pin.
8.Continue rotating crankshaft clockwise until
centre pin engages with timing slot in flywheel.
9.Remove injection pump access plate, complete
with gasket, from front cover plate.
10.Fit pin from LRT-12-045 to injection pump gear.
11.Remove drive gear to pump hub fixing bolts and
plate.

19FUEL SYSTEM
12
REPAIR 12.Remove pin from pump gear.
13.Fit gear retaining tool LRT-12-045 with an 8 mm
washer, 1.5 to 2 mm thick, under each bolt head
in addition to the existing washer.
14.Remove throttle cable and hand throttle cable if
fitted.15.Disconnect stop control solenoid connector.
16.Remove banjo bolts securing spill return, main
fuel and boost signal pipes, refit banjo bolts after
disconnecting pipes.
17.Remove pump mounting bracket bolts 2 off.
18.Loosen pump support bracket bolts to block,
sufficient for bracket to just move.
19.Remove pump securing nuts at flange and
withdraw pump and gasket.
20.Fit blanks to pipe connections.

Tdi
13
REPAIR Refit
21.Remove blanks from pump.
22.Remove special tool pin from pump.
23.Clean mating faces of pump and front cover.
24.Fit pump to cover with a new gasket and secure
with nuts. Tighten to
25 Nm.
25.Attach pump to bracket and finger tighten nuts
and bolts
26.First tighten bolts securing bracket to block and
then bolts securing pump to bracket.
27.Connect spill return, main fuel pipes. Tighten to
25 Nm.
28.Connect boost signal pipe and secure with banjo
bolts. Tighten to
10 Nm.
29.Connect stop control solenoid lead.
30.Connect throttle cable and where applicable
hand throttle cable.
31.Remove special tool LRT-12-045.
32.Fit gear lock plate.
33.Fit pin from special tool LRT-12-045.
34.Secure gear with bolts.
35.Remove special tool pin.
36.Turn crankshaft two complete revolutions, check
timing pin from LRT-12-045 can be fully and
easily inserted into the pump. At the same time
check flywheel timing pin LST-12-044 can also
be inserted in the flywheel slot.
37.If, with the flywheel timing pin located, the timing
pin cannot be inserted cleanly into the injection
pump, carry out the following:
(a) Ensure flywheel timing pin is disengaged
from slot in flywheel.
(b) Turn the crankshaft the small amount
necessary to enable the timing pin to be
inserted into the pump.
(c) Loosen the three pump gear retaining
bolts.
(d) Turn the crankshaft to T.D.C..
(e) Check that the timing pin is an easy fit in
the pump and that the flywheel timing pin
locates.
(f) Tighten the pump gear retaining bolts to
the correct torque.
(g) Remove the timing pin from the pump and
the timing tool from the flywheel housing.
38.Using antisieze compound, fit the blanking plug
to flywheel housing. Tighten to
12 Nm.
39.Fit access plate with gasket to front cover plate.
Tighten to
25 Nm.
40.Refit injector pipes. Tighten to29 Nm.

19FUEL SYSTEM
14
REPAIR ENGINE CONTROL MODULE (ECM)
Service repair no - 18.30.03
NOTE: The ECM is not a serviceable item,
in the event of failure it must be renewed.
Remove
1.Disconnect battery negative lead.
2.Remove 'A' post trim pad.
3.Loosen multi-plug screw to ECM.
4.Disconnect multi-plug from ECM.
5.Secure multi-plug and harness aside.
6.Remove retaining nuts from ECM.
7.Manoeuvre ECM from its mounted position.
Refit
8.Refitting is the reverse of removal procedure.
9.Reconnect harness plug. Ensure plug is pushed
firmly into location and retaining clip secures
plug in position.
10.Tighten screw securing multi-plug.AIRFLOW METER
Service repair no - 18.30.15
NOTE: The air flow meter is not a
serviceable item, in the event of failure it
must be renewed.
Remove
1.Disconnect battery negative lead.
2.Release vacuum tube from EGR vacuum
capsule.
3.Disconnect airflow meter multi-plug.
4.Loosen air cleaner hose to air flow meter
retaining clip.
5.Disconnect hose from airflow meter.
6.Loosen turbo charger hose to airflow meter
retaining clip.
7.Disconnect hose from airflow meter.
8.Remove meter to mounting bracket bolts.
9.Remove airflow meter.
Refit
10.Reverse removal procedure. Ensure multi-plug is
firmly reconnected and hose clamps are
securely tightened to prevent unmetered air
entering the engine.

19FUEL SYSTEM
16
REPAIR ENGINE SPEED SENSOR
Service repair no - 18.30.65
Remove
1.Disconnect battery negative lead.
2.Disconnect sensor multi-plug.
3.Place vehicle on ramp and apply handbrake.
4.Raise ramp.
5.Remove sensor retaining nut.
6.Remove sensor from housing.
7.Clean housing mating faces.
Refit
8.Reverse removal procedure.

19FUEL SYSTEM
18
REPAIR BRAKE PEDAL SWITCH
Service repair no - 18.30.66
Remove
1.Disconnect battery negative lead.
2.Disconnect switch wiring Lucars.
3.Loosen rear locknut.
4.Remove front locknut.
5.Remove switch from mounting bracket.
Refit
6.Reverse removal procedure.COOLANT TEMPERATURE SENSOR
Service repair no - 18.30.68
Remove
1.Disconnect battery negative lead.2.Disconnect sensor multi-plug.
3.Remove sensor.
4.Clean off water spillage from sensor area.
Refit
5.Fit a new copper washer.
6.Fit sensor and tighten securely.
7.Refill cooling system.
8.Run engine, check for water leaks around
sensor.

MFI
1
DESCRIPTION AND OPERATION DESCRIPTION
Hot Wire Multiport Fuel Injection
The 'Hot Wire' Multiport fuel injection system derives
its name from the mass air flow sensor which uses
one cold wire and one electrically heated wire to
measure the volume of air entering the engine.
The function of the system is to supply the exact
amount of fuel directly into the intake manifold
according to the prevailing engine operating
conditions.
To monitor these conditions, various sensors are fitted
to the engine to measure engine parameters. Data
from the sensors is received by the Engine control
module (ECM), the ECM will then determine the exact
amount of fuel required at any condition.
The ECM having received data from the sensors
produces pulses, the length of which will determine
the simultaneous open time of each bank of injectors
in turn, which will govern the amount of fuel injected.
Engine control module - ECM
The Multiport fuel injection system is controlled by the
14 CUX Engine Control Module comprising of a
microprocessor with integrated circuits and
components mounted on printed circuit boards. The
ECM is connected to the main harness by a 40 pin
plug.
Injectors
The eight fuel injectors are fitted between the
pressurized fuel rail and inlet manifold. Each injector
comprises a solenoid operated needle valve with a
movable plunger rigidly attached to the nozzle valve.
When the solenoid is energized the plunger is
attracted off its seat and allows pressurized fuel into
the intake manifold.Engine coolant temperature sensor
The engine coolant temperature sensor is located in
the front of the thermostat housing. The sensor
provides engine coolant information to the ECM. The
ECM increases the injector opening time when cold to
provide improved driveability, and reduces the
opening time as the engine reaches normal operating
temperature.
Engine fuel temperature sensor
The engine fuel temperature sensor is located in the
rail on the RH side of the ram housing. The sensor
sends fuel temperature data to the ECM, the ECM on
receiving the data will adjust the injector open time
accordingly to produce good hot starting in high
ambient temperatures.
Idle air control valve
The idle air control valve is screwed into a housing
attached to the rear of the plenum chamber, between
the plenum chamber and bulkhead. The idle air
control valve has two windings which enable the
motor to be energised in both directions thus opening
or closing the air valve as required by the ECM.
The idle air control valve will open and allow extra air
into the plenum chamber to maintain engine idle
speed when the engine is under increased (Electrical
and Mechanical) loads.
The idle air control valve will control engine idle speed
when the vehicle is stationary.
Heated oxygen sensors (0
2sensors) - Catalyst
vehicles
The two heated oxygen sensors are located forward
of the catalysts mounted in the exhaust downpipes.
The sensors monitor the oxygen content of the
exhaust gases and provide feedback information of
the air/fuel ratio to the ECM. Each sensor is heated by
an electrical element to improve its response time
when the ignition is switched on.

19FUEL SYSTEM
2
DESCRIPTION AND OPERATION Fuel pressure regulator
The fuel pressure regulator is mounted in the fuel rail
at the rear of the plenum chamber. The regulator is a
mechanical device controlled by plenum chamber
vacuum, it ensures that fuel rail pressure is
maintained at a constant pressure difference of 2.5
bar above that of the manifold.
When pressure exceeds the regulator setting excess
fuel is returned to the fuel tank.
Fuel pump
The electric fuel pump is located in the fuel tank, and
is a self priming 'wet' pump, the motor is immersed in
the fuel within the tank.
Air flow sensor
The hot-wire air flow sensor is mounted on a bracket
attached to the left hand valance, rigidly connected to
the air cleaner and by hose to the plenum chamber
inlet neck.
The air flow sensor consists of a cast alloy body
through which air flows. A proportion of this air flows
through a bypass in which two wire elements are
situated: one is a sensing wire and the other is a
compensating wire. Under the control of an electronic
module which is mounted on the air flow sensor body,
a small current is passed through the sensing wire to
produce a heating effect. The compensating wire is
also connected to the module but is not heated, but
reacts to the temperature of the air taken in, as engine
intake air passes over the wires a cooling effect takes
place.
The electronic module monitors the reaction of the
wires in proportion to the air stream and provides
output signals in proportion to the air mass flow rate
which are compatible with the requirements of the
ECM.Throttle position sensor
The throttle position sensor is mounted on the side of
the plenum chamber inlet neck and is directly coupled
to the throttle butterfly shaft.
The throttle position sensor is a resistive device
supplied with a voltage from the ECM. Movement of
the accelerator pedal causes the throttle valve to
open, thus rotating the wiper arm within the throttle
position sensor which in turn varies the resistance in
proportion to the valve position. The ECM lengthens
the injector open time when it detects a change in
output voltage (rising) from the throttle position
sensor.
In addition the ECM will weaken the mixture when it
detects the throttle position sensor output voltage is
decreasing under deceleration and will shorten the
length of time the injectors are open.
When the throttle is fully open, the ECM will detect the
corresponding throttle position sensor voltage and will
apply full load enrichment. This is a fixed percentage
and is independent of temperature. Full load
enrichment is also achieved by adjusting the length of
the injector open time.
When the throttle is closed, overrun fuel cut off or idle
speed control may be facilitated dependant on other
inputs to the ECM.
The throttle position sensor is 'self adaptive', which
means that adjustment is not possible. It also means
the throttle position sensor setting is not lost, for
example, when throttle stop wear occurs.
CAUTION: Do not attempt to adjust throttle
position sensor.