cooling LAND ROVER DISCOVERY 1995 Owner's Manual

4.0 V8
9
REPAIR 28.Remove alignment tool LRT-12-090.
29.Apply a small amount of Loctite 242 to threads
and refit front cover bolts. Tighten to
22 Nm.
30.Fit sump bolts. Tighten to23 Nm.
31.Connect camshaft sensor multiplug.
32.Connect Lucar to oil pressure switch terminal.
33.Remove plugs from oil cooler pipes and cover.
34.Fit new 'O' ring seals, reconnect oil cooler pipes.
Tighten to
15 Nm.
CAUTION: Over tightening of oil cooler
pipe unions can crack front cover.
35.Refit bottom hose to water pump. Tighten clip.
36.Refit water pump pulley.
See COOLING
SYSTEM, Repair, Viscous Coupling, Fan
Blades, Pulley and Fan Cowl
37.Refit radiator assembly.See COOLING
SYSTEM, Repair, Radiator
38.Refill cooling system.See COOLING SYSTEM
V8, Adjustment, Coolant
39.Check/top-up engine oil.
40.Lower ramp.
41.Reconnect battery negative lead.

4.0 V8
11
REPAIR ROCKER COVER GASKET - RIGHT HAND
Service repair no - 12.29.41 - RH Cover Gasket
1.Depressurise fuel system.
See FUEL SYSTEM
SFI, Repair, Fuel System - Depressurise
2.Disconnect battery negative lead.3.Drain cooling system.
See COOLING SYSTEM
V8, Adjustment, Coolant
NOTE: Leave hose disconnected.
4.Disconnect purge pipe from plenum chamber
hose.
5.Disconnect breather pipe from rocker cover.
6.Remove bolt securing coolant pipe brackets and
nut securing bracket to manifold.
7.Loosen hose clip and disconnect coolant return
hose from pipe.
CAUTION: Plug connection.
8.Loosen clip and disconnect fuel return hose from
pipe.
9.Disconnect fuel hose from injector pipe.
CAUTION: Use 2 spanners.10.Remove 2 nuts securing engine harness
brackets to manifold.
11.Release 4 ht leads from 2 brackets on rocker
cover.

12ENGINE
12
REPAIR
12.Remove 4 bolts securing rocker cover to cylinder
head.
13.Remove rocker cover.
14.Remove and discard rocker cover gasket.Refit
15.Clean mating faces between rocker cover and
cylinder head using Bostick cleaner 6001 or
equivalent. Allow to dry.
NOTE: Gasket fits one way round only. It
must be fitted accurately, first time.
Subsequent movement will destroy
bonding.
16.Apply a thin coating of impact adhesive (Bostick
1775 or equivalent) to mating faces of rocker
cover seal face and new gasket. Use a brush to
ensure an even film. Allow adhesive to become
touch dry.
17.Place one end of gasket into cover recess with
edge firmly against recess wall, holding
remainder of gasket clear. Work around cover,
pressing gasket into place ensuring edge firmly
contacts recess wall.
CAUTION: Allow cover to stand for thirty
minutes before fitting.
18.Fit rocker cover to cylinder head, ensure short
screws are inboard. Tighten to
9 Nm.
19.Connect fuel feed and return hoses.
20.Refit ht leads into retaining brackets.
21.Secure engine harness to brackets.
22.Connect coolant pipes to hoses and secure
brackets.
23.Connect breather hose to rocker cover.
24.Connect purge hose to plenum chamber.
25.Connect bottom hose to radiator.
26.Refill cooling system.
See COOLING SYSTEM
V8, Adjustment, Coolant
27.Reconnect battery negative lead.

12ENGINE
6
REPAIR ENGINE
Service repair no - 12.41.01
Remove
1.Site vehicle onto ramp [hoist].
2.Remove the drive belt.
See SECTION 10,
Maintenance, Under Bonnet [Hood]
Maintenance
3.Remove radiator.See COOLING SYSTEM,
Repair, Radiator - Mpi
4.Remove bonnet [hood].See CHASSIS AND
BODY, Repair, Bonnet [Hood]
5.Drain engine oil.
6.Position absorbent cloth around fuel pipe to fuel
rail union.
Unscrew union to relieve pressure.
CAUTION: Plug the connections
7.Release clip and disconnect hose from coolant
pump.
8.Release clip and disconnect hose from heater
rail.

Mpi
13
REPAIR 19.Connect crankshaft sensor, knock sensor, air
conditioning compressor, fuel injector harness,
inlet manifold air temperature and fuel
temperature sensor multiplugs.
20.Connect fuel hose to pressure regulator and
secure with clip.
21.Fit and tighten fuel pipe to fuel rail union.
22.Connect multiplugs to throttle housing.
23.Connect vacuum hose to manifold.
24.Connect oil pressure switch multiplug.
25.Connect brake servo hose to manifold, secure
with clip.
26.Connect throttle cable to cam.
27.Position engine harness and connect breather
hose to inlet manifold, secure with clip.
28.Connect coolant temperature sensor multiplugs,
secure harness with cable tie.
29.Connect oxygen sensor multiplug, secure
harness with cable tie.
30.Connect alternator harness.
31.Connect heater hose to heater rail and secure
with clip.
32.Connect hose to coolant pump and secure with
clip.
33.Connect inlet hose to power steering pump and
secure with clip.
34.Fit and tighten outlet pipe union to power
steering pump.
35.Connect bypass and top hose, secure with clip.
36.Connect air cleaner to throttle housing hose and
secure with clip.
37.Remove engine lifting bracket.
38.Position spark plug cover and secure with
screws.
39.Fill engine with oil.
40.Fit bonnet [hood].
See CHASSIS AND BODY,
Repair, Bonnet [Hood]
41.Fit radiator.See COOLING SYSTEM, Repair,
Radiator - Mpi
42.Adjust throttle cable.See FUEL SYSTEM,
Adjustment, Throttle Cable Adjustment
ENGINE SUMP GASKET
Service repair no - 12.60.43
Remove
1.Drain engine oil.
2.Refit drain plug, use new sealing washer if
necessary, tighten to the correct torque.
3.Remove 18 bolts securing sump.
NOTE: 25mm long bolt is fitted at rear L.H.
corner of sump.
4.Release sump from cylinder block.
5.Discard gasket.

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.

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.

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.

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
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.