LAND ROVER DISCOVERY 1995 Workshop Manual

19FUEL SYSTEM
4
REPAIR
NOTE: If rotary coupler is to be re-used a
piece of adhesive tape should be placed
around the moulding in position A to
prevent rotation. Failure to do this may result in
damage to the wires inside the coupler.
6.Release clips securing rotary coupler to column
stalk assembly.
7.Remove rotary coupler from column stalk
assembly.
CAUTION: Ensure front wheels are in the
straight ahead position before removal
and refitting. Store in a plastic bag. DO
NOT rotate mechanism whilst removed.
Refit
8.Reverse removal procedure. Ensuring that the
column harnesses are not trapped by the
column shroud.
NOTE: If original rotary coupler is to be
fitted and there is evidence of tampering, it
is imperative that the coupler is
centralised.
See SUPPLEMENTARY RESTRAINT
SYSTEM, Repair, Rotary Coupler
NOTE: If a new rotary coupler is to be
fitted and the sealing tape is broken it
MUST NOT be used. Ensure rotary coupler
lugs are correctly engaged in the rear of the
steering wheel.ACTUATOR - V8i
Service repair no - 19.75.12
NOTE: The actuator is non serviceable, fit
a new unit if failure or damage occurs.
Remove
1.Disconnect battery negative lead.
2.Disconnect vacuum hose from actuator.
3.Remove nut securing actuator to throttle bracket.
4.Remove actuator, and manoeuvre actuator
operating link off throttle lever.
5.Withdraw actuator.
Refit
6.Inspect rubber diaphragm. Fit a new actuator
assembly if diaphragm is damaged.
7.Reverse removal procedure. Fitting the hook
uppermost.

CRUISE CONTROL
5
REPAIR ACTUATOR LINK-SETTING - V8i
Service repair no - 19.75.21
NOTE: Setting procedure is carried out at
minimum throttle condition only.
1.Ensure ignition is switched 'OFF'.
2.Check clearance between inside edge of
actuator link and recessed diameter of throttle
lever. Clearance should be 0.2 to 2.0 mm.
Link - adjust
3.Remove link from actuator.
4.Rotate socket joint adjuster as necessary.
5.Refit link to actuator and recheck clearance
between link and lever.
6.With throttle fully open, check a gap of at least
3mm exists between side of link ("A" in
illustration) and side of small spring ("B" in
illustration). Realign link by bending to achieve
correct gap. Recheck clearance at closed
throttle/open throttle. Check link slides smoothly
in groove of throttle lever.

19FUEL SYSTEM
6
REPAIR VACUUM PUMP - TDI
Service repair no - 19.75.06
NOTE: The vacuum pump is non
serviceable, fit a new unit if failure or
damage occurs.
Remove
1.Release turnbuckle securing wheel chock and
remove.
2.Release strap securing jack and remove.
3.Release 3 pump mounting rubbers from vehicle
body.
4.Manoeuvre pump out of box section.
5.Release multiplug cover and disconnect
multiplug from pump.
6.Disconnect vacuum hose from pump.
7.Remove pump.
Refit
8.Reverse removal procedure. Ensure all hose
and electrical connections are secure.

CRUISE CONTROL
7
REPAIR CRUISE CONTROL ECU - V8i
Service repair no - 19.75.49
Remove
1.Remove lower dash panel.
2.Disconnect ECU multi-plug.
3.Remove ECU fixing.
4.Remove ECU.
5.Reverse removal procedure. Ensuring that
electrical multi-plug is securely reconnected.
SPEED TRIP ECU - MANUAL V8i
NOTE: The neutral lock out relay
module/speed trip ECU is mounted in the
right hand side footwell. To identify
components.
See Electrical Trouble Shooting
Manual.
VEHICLE SPEED SENSOR
Service repair no - 18.30.22
For Tdi
See FUEL SYSTEM Tdi, Repair, Vehicle
Speed Sensor
For V8iSee FUEL SYSTEM MFI, Repair, Vehicle
Speed Sensor
NEUTRAL LOCK OUT RELAY
Service repair no - 19.75.28
1.Remove 3 studs securing fascia right hand side
closing panel.
2.Release and move closing panel aside.
3.Remove 2 studs securing right hand side 'A' post
lower trim casing.
4.Remove casing.
5.Locate relay (neutral coloured base) and release
base from bracket.
6.Remove relay.
NOTE: For further information.See
Electrical Trouble Shooting Manual.
Refit
7.Reverse removal procedure.

19FUEL SYSTEM
8
REPAIR ACTUATOR - Tdi
Service repair no - 19.75.05
NOTE: The actuator is non serviceable, fit
a new unit if failure or damage occurs.
Remove
1.Disconnect battery negative lead.
2.Remove split pin, withdraw clevis pin and
disconnect cable from lever.
3.Disconnect link ball end from cable lever.
4.Disconnect vacuum hose from actuator.
5.Remove nut securing actuator to bracket and
remove actuator.
6.Inspect rubber diaphragm. Fit a new actuator
assembly if diaphragm is damaged.Refit
7.Check that link setting distance (dimension 'A')
equals 16 mm and that the retainer is locked in
position. If correct, proceed to paragraph 9.
8.If dimension 'A' is not correct, proceed as
follows:
·Measure 16 mm from diaphragm collar and
mark the position.
·Position link and retainer to the mark and
rotate retainer half a turn to secure.
·Check measurement 'A' is still 16 mm, then
turn retainer a further quarter turn to lock.
9.Fit actuator and secure to bracket with nut.
10.Connect vacuum hose.
11.Connect link ball end to cable lever.
12.Connect cable to lever and secure with clevis pin
and split pin.
13.Adjust cable position to remove any free play
from link, setting dimension 'B' should be 103
mm.

CRUISE CONTROL
9
REPAIR CRUISE CONTROL ECU - Tdi
Service repair no - 19.75.49
Remove
1.Remove 4 studs securing fascia left hand
closing panel.
2.Remove closing panel.
3.Remove nut securing ECU/relay bracket.
4.Lower bracket for access.
5.Remove bottom nut securing ECU to bracket.
6.Open glove box, align stops with cut-outs in
fascia panel and lower.
7.Move SRS harness aside.
8.Remove top nut securing ECU to bracket.
9.Disconnect ECU multiplug.
10.Remove ECU.
Refit
11.Reverse removal procedure. Ensure electrical
multiplug is securely reconnected.

Tdi
1
DESCRIPTION AND OPERATION ENGINE COOLING
Description
The Tdi engine uses a pressurized cooling system
and cross flow radiator which is supplied from a
separate header tank. The radiator assembly is in
three sections. The largest section is for engine
coolant and the other two sections which are cast in
aluminium, are the engine oil cooler and the turbo
charger intercooler.
A belt driven viscous fan and centrifugal water pump
is located in the front of the cylinder block. Hot coolant
is supplied to the heater through hoses. Two small
diameter air purge hoses connect the top of the
radiator and cylinder head water gallery, to the header
tank.
Coolant circulation (engine cold)
1. Cross flow radiator
2. Header tank
3. Viscous fan
4. Heater hoses
5. By pass hose and engine thermostat
6. Air purge hoses
7. Coolant pumpCOOLANT CIRCULATION
Operation
When the engine is started from cold the thermostat
prevents any coolant circulation through the radiator
by closing off the top hose. During the engine warm
up period, the water pump, pumps coolant towards
the rear of the cylinder block around each of the
cylinders. Coolant as it is heated rises through ports in
the cylinder block and head gasket, into the cylinder
head.The coolant flows forwards to the thermostat,
by-pass port and radiator top hose connection.
Start from cold (thermostat closed)
While the thermostat is closed, coolant circulates
around the cylinder block and cylinder head via the
by-pass.
Engine warm (thermostat open)
When the engine reaches normal running temperature
the thermostat closes off the by-pass and opens the
flow to the top of the radiator.

26COOLING SYSTEM
2
DESCRIPTION AND OPERATION VISCOUS FAN
Description
The viscous drive unit for the engine cooling fan,
provides a means of controlling the speed of the fan
relative to the running temperature of the engine. The
viscous unit is a type of fluid coupling, which drives
the fan blades through the medium of a special
'silicone fluid' injected into the unit during
manufacture.
1. Drive in from water pump spindle
2. Drive out to fan blades
3. Bi-metalOperation
The viscous unit consists of two principal components:
An inner member 1 which is secured to water pump
spindle and is driven by the fan belt.
An outer member 2 which has the fan blades
attached, houses the working parts and is driven
through the medium of the viscous fluid.
The inner and outer members have interlocking
annular grooves machined in each, with a small
running clearance 3 to allow the silicone fluid to
circulate through the valve plate 4.
The unit also contains a valve 5 which is controlled by
an external bi-metal thermostat 6.
Starting engine from cold
During the time the engine is at rest the silicone fluid
drains down, half filling chambers A and B. Thus when
the engine is first started sufficient fluid is present in
chamber A to provide a positive drive between the
members, as is evident by the initial noise of the fan.
However within a very short period of time, after
starting the engine, the fan speed and noise will
decline indicating that the fluid is being centrifuged
into chamber B (as seen in RR3757M) causing the
drive to slip.

Tdi
3
DESCRIPTION AND OPERATION
Viscous unit slipping (Engine at normal running
temperature)
1. Inner member (drive in fast)
2. Outer member (drive out slow)
3. Running clearance
4. Valve plate
5. Valve (closed)
6. Bi-metal
7. Fluid seals
8. Ball race
AFluid chamber
BFluid chamber
If the engine speed is increased the degree of slip will
also increase to limit the maximum fan speed.Hot conditions
When operating in high ambient temperatures or
when stationary in traffic, the bi-metel thermostat will
operate and open the valve port between chambers A
and B.
Opening the valve (as shown in RR3758M) allows the
fluid to circulate between the two members, causing
the unit to couple, thus increasing the fan speed and
cooling effect.
Viscous unit coupled (Hot running conditions)
Bi-metal expanded, valve (open)

Tdi
1
FAULT DIAGNOSIS ENGINE OVERHEATING
Before conducting any cooling system diagnosis:
See
Description and operation, Engine Cooling
1.Is coolant level correct?
NO - Allow engine to cool, top up level to
expansion tank seam.
YES - Continue.
2.Is drive belt tension correct?
NO -
See ENGINE, Repair, Compressor
Drive Belt
YES - Continue.
3.Is coolant in radiator frozen?
YES - Slowly thaw and drain system.
See
Adjustment, Coolant
NO - Continue.
4.Is air flow through radiator restricted or blocked?
YES - Apply air pressure from engine side of
radiator to clear obstruction.
NO - Continue.
5.Are there any external leaks, from water pump,
engine gaskets, fast idle thermostat or the heater
unit?
YES - Investigate and rectify.
See Adjustment,
Coolant
NO - Continue.
6.Are fan blades fitted correct way round, concave
side towards engine?
NO - Rectify.
YES - Continue
7.Is viscous unit operating correctly?
See
Description and operation, Viscous Fan
NO - Renew.See Repair, Viscous
Coupling, Fan Blades, Pulley and Fan
Cowl
YES - Carry out a pressure test on radiator cap
and system. Check thermostat type,
operation and correct fitting.
See Repair,
Thermostat
If pressure test leads you to suspect coolant
leakage across gaskets, go to check 10,
otherwise: Continue.8.Are the air conditioning fans operating correctly?
See Electrical Trouble Shooting Manual.
NO - Rectify.
YES - Continue.
9.Is temperature sender and gauge giving
accurate readings?
NO - Sustitute parts and compare readings.
YES - Continue.
10.Carry out cylinder pressure test to determine if
pressure is leaking into cooling system causing
over pressurising and loss of coolant.
If problem is not diagnosed, check the coolant system
for engine oil contamination and engine lubrication
system for coolant contamination.
If only the coolant system is contaminated suspect a
cylinder head gasket.
If both systems are contaminated, suspect the
radiator.
If only the lubrication system is contaminated with
coolant, suspect leakage past cylinder liner seals or
cylinder head gasket.