1995 LAND ROVER DISCOVERY coolant

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.

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.

19FUEL SYSTEM
4
DESCRIPTION AND OPERATION ENGINE MOUNTED COMPONENTS
1. By-pass air valve (stepper motor).
2. Fuel pressure regulator.
3. Air flow meter.
4. Throttle potentiometer.
5. Fuel temperature sensor.
6. Coolant temperature sensor.
7. Fuel injector.

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).

19FUEL SYSTEM
8
REPAIR 10.Remove fuel rail and injectors.
11.Remove injector retaining clips, ease injectors
from rail. Remove and discard 'O' rings from
injectors.
12.Remove fuel pressure regulator if required.
Refit
13.FitNEW'O' rings, to injectors. Lightly coat 'O'
rings with silicon grease 300. Insert injectors into
fuel rail, multi-plug connections facing outwards.
14.Refit retaining clips.
CAUTION: Care must be taken when
refitting the fuel rail and injectors to intake
manifold to prevent damage to 'O' rings.
15.Fit aNEW'O' ring to pressure regulator lightly
coat 'O' ring with silicon grease 300 and secure
regulator to the fuel rail.
16.Fit fuel rail and heater pipe assemblies to intake
manifold. Secure rail and pipes in position with
five bolts.
17.Reverse removal procedure. 2 to 7.
18.Pressurise fuel system and check for fuel leaks
around injectors and pressure regulator.PLENUM CHAMBER
Service repair no - 19.22.46
Includes throttle levers and throttle disc
Remove
1.Disconnect battery negative lead.
2.Disconnect electrical multi-plug from bypass air
valve.
3.Disconnect vacuum hose adjacent to bypass air
valve.
4.Mark an identification line on throttle cable outer
to assist re-assembly.
5.Remove clevis pin from throttle cable.
6.Pry adjustment thumb wheel from throttle
bracket. Lay cable aside.
7.Remove retaining clip and clevis pin from kick
down cable (automatic vehicles).
8.Apply adhesive tape behind rear adjustment nut
on kick down cable to prevent nut moving.
9.Remove front lock nut. Remove cable and lay
aside.
10.Remove cruise control vacuum hose.
11.Remove intake hose from neck of plenum
chamber.
12.Disconnect throttle position sensor multi-plug.
13.Remove PCV breather hose.
14.Disconnect two coolant hoses and plug each
hose to prevent excessive loss of coolant.
Identify each hose for re-assembly.

19FUEL SYSTEM
14
REPAIR RAM HOUSING
Service repair no - 19.70.04
Remove
1.Disconnect battery negative lead.
2.Remove plenum chamber.
See Plenum
Chamber
3.Release hoses from ram housing.
4.Remove six through bolts (with plain washers)
securing ram housing to intake manifold.
5.Remove ram housing from intake manifold.
6.Place a protective cover over inlet bores to
prevent ingress of dirt.
Refit
7.Clean all mating faces.
8.Apply 'Hylomar' sealant to intake manifold face.
9.Fit ram housing. Tighten bolts, working from two
centre bolts, diagonally towards outer four bolts.
10.Tighten to
26 Nm.
INTAKE MANIFOLD
Service repair no - 30.15.08
Remove
1.Depressurise fuel system.
See Depressurising
Fuel System
2.Disconnect battery negative lead.
3.Drain cooling system.
See COOLING SYSTEM,
Repair, Radiator
4.Remove plenum chamber.See Plenum
chamber
5.Remove ram housing.See Ram Housing
CAUTION: Place a protective cover over
intake manifold openings to prevent the
ingress of dirt.
6.Disconnect the fuel temperature sensor and
injector multiplugs.
7.Remove fuel pressure regulator.
See Fuel
Pressure Regulator
8.Disconnect multiplug from coolant temperature
sensor.
9.Disconnect instrument pack temperature
thermistor.
10.Disconnect coolant sensor multiplug.

MFI
15
REPAIR 11.Loosen clip and disconnect top hose from
thermostat housing.
12.Disconnect multiplug from distributor amplifier
module.
13.Loosen clip and disconnect hose from heater
valve.
14.Remove injector harnesses from behind fuel rail
and lay to one side.
15.Loosen union and disconnect fuel return hose
from fuel rail.
NOTE: The intake manifold can be
removed from the cylinder block without
removing the fuel rail and injectors.
16.Using the sequence shown, remove 12 bolts
securing the intake manifold to cylinder block.
17.Remove the intake manifold.
18.Noting their fitted position, remove bolts and
clamps securing intake manifold gasket to
cylinder block.
19.Remove and discard gasket.
20.Remove and discard gasket seals.
Do not carry out further dismantling if component
is removed for access only.
21.Remove 5 nuts securing fuel rail support
brackets to intake manifold.
22.Remove fuel rail and injectors.
23.Remove 2 bolts securing thermostat housing to
intake manifold.
24.Remove thermostat housing.
25.Remove bolt securing coolant pipe to intake
manifold. Loosen union and remove coolant
pipe. Remove and discard 'O' ring.
26.Fit new 'O' ring to coolant pipe. Position coolant
pipe to intake manifold. Fit bolt securing coolant
pipe support bracket to intake manifold and
tighten pipe union.
27.Clean mating faces of thermostat housing and
intake manifold.
28.Fit thermostat housing to intake manifold using a
new gasket, fit and tighten bolts.
29.Position fuel rail to intake manifold, fit and
tighten retaining bolts.