change time LAND ROVER DISCOVERY 1995 Workshop Manual

01INTRODUCTION
4
INFORMATION ACCESSORIES AND CONVERSIONS
DO NOT FITunapproved accessories or conversions,
as they could affect the safety of the vehicle.
Land Rover will not accept liability for death, personal
injury, or damage to property which may occur as a
direct result of the fitting of non-approved conversions
to the vehicle.
WHEELS AND TYRES
WARNING: DO NOT replace the road
wheels with any type other than genuine
Land Rover wheels which are designed for
multi-purpose on and off road use and have very
important relationships with the proper operation
of the suspension system and vehicle handling.
Replacement tyres must be of the make and sizes
recommended for the vehicle, and all tyres must
be the same make, ply rating and tread pattern.
STEAM CLEANING
To prevent consequential rusting, any steam cleaning
within the engine bayMUSTbe followed by careful
re-waxing of the metallic components affected.
Particular attention must be given to the steering
column, engine water pipes, hose clips and ignition
coil clamp.
SPECIFICATION
The specification details and instructions set out in
this Manual apply only to a range of vehicles and not
to any one. For the specification of a particular vehicle
purchasers should consult their Dealer
The Manufacturer reserve the right to vary their
specifications with or without notice, and at such times
and in such manner as they think fit. Major as well as
minor changes may be involved in accordance with
the Manufacturer's policy of constant product
improvement.
Whilst every effort is made to ensure the accuracy of
the particulars contained in this Manual, neither the
Manufacturer or Dealer, by whom this Manual is
supplied, shall in any circumstances be held liable for
any inaccuracy or the consequences thereof.SPECIAL SERVICE TOOLS
The use of approved special service tools is
important. They are essential if service operations are
to be carried out efficiently, and safely. Where special
tools are specified,only these tools should be used
to avoid the possibility of personal injury or
damage to the components.Also the amount of time
which they save can be considerable.
Every special tool is designed with the close
co-operation of Land Rover, and no tool is put into
production which has not been tested and approved
by us. New tools are only introduced where an
operation cannot be satisfactorily carried out using
existing tools or standard equipment. The user is
therefore assured that the tool is necessary and that it
will perform accurately, efficiently and safely.
Special tools bulletins will be issued periodically giving
details of new tools as they are introduced.
All orders and enquiries from the United Kingdom
should be sent direct to V. L. Churchill. Overseas
orders should be placed with the local V. L. Churchill
distributor, where one exists. Countries where there is
no distributor may order direct from:
V. L. Churchill Limited,
PO Box 3,
Daventry, Northants,
England, NN11 4NF.
The tools recommended in this Workshop Manual are
listed in a multi-language illustrated catalogue,
obtainable from:
Messers. V. L. Churchill at the above address,
or from:
Land Rover Merchandising Service,
PO Box 534,
Erdington,
Birmingham, B24 0Q5,
COPYRIGHT
ÓLand Rover 1996
All rights reserved. No part of this publication may be
produced, stored in a retrieval system or transmitted
in any form, electronic, mechanical, recording or other
means without prior written permission of Land Rover.

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
4
DESCRIPTION AND OPERATION Throttle position sensor (TP Sensor)
The throttle position sensor is mounted on the plenum
chamber and connected directly to the throttle shaft.
The sensor is a variable resistor, the signal from
which (0 - 5V) informs the ECM of the actual position
of the throttle disc. As there is no default strategy,
failure of the sensor will result in poor idle and lack of
throttle response. If failure occurs in the closed
position the engine will only reach 1750 rev/min when
the ECM will initiate overrun fuel cut off. The fault is
indicated by illumination of the malfunction indicator
light (MIL) on North American specification vehicles.
Engine coolant temperature sensor (ECT Sensor)
This sensor consists of a temperature dependant
resistive metal strip. The resistance of the strip varies
considerably with coolant temperature, i.e. from 28K
ohms at - 30°C to 90 ohms at 130°C, and 300 Ohms
at 85°C. The ECT Sensor signal is vital to engine
running, as the correct fuelling is dependant upon
engine temperature i.e. richer mixture at low
temperatures. If the sensor is disconnected or failure
occurs a default value will be supplied to the system.
The initial default value selected will be based on the
value of the air intake temperature. This will increase
to a nominal warmed up value over an individual time,
programmed for each default value. The fault may not
be evident to the driver, there may be a hot restart
problem. The fault is indicated by illumination of the
malfunction indicator light (MIL) on North American
specification vehicles.Intake air temperature sensor (IAT Sensor)
This is another resistive sensor, located in the body of
the air cleaner. The resistance varies with changes in
air temperature. The signal from the IAT Sensor is
used to retard the ignition timing if the air temperature
rises above 55°C. If the sensor is disconnected or
failure occurs a default value will be supplied to the
system. The default value selected will represent
normal operating conditions. The fault may not be
evident to the driver, there may be slight power loss in
high ambient temperatures. The fault is indicated by
illumination of the malfunction indicator light (MIL) on
North American specification vehicles.

SFI
5
DESCRIPTION AND OPERATION REV: 09/95 Engine fuel temperature sensor (EFT Sensor)
This is another resistive sensor. Located on the fuel
rail it measures temperature of the rail rather than the
fuel. The resistance varies with changes in
temperature. The signal is used to increase the
injection pulse time when undergoing hot restarts.
When the fuel is hot, vapourisation occurs in the rail
and bubbles can occur in the injectors. Increasing the
pulse time flushes the bubbles away, and cools the
fuel rail with fuel from the tank. The fault may not be
evident to the driver, there may be a hot restart
problem. The fault is indicated by illumination of the
malfunction indicator light (MIL) on North American
specification vehicles.
Knock sensors
The knock sensor produces an output voltage in
proportion to mechanical vibration caused by the
engine. A sensor is located in each cylinder bank
between 2/4 and 3/5 cylinders. The ECM calculates if
the engine is knocking due to camshaft and
crankshaft sensor signals regarding the position of the
engine in the cycle. The ECM can also work out
exactly which cylinder is knocking and retards the
ignition on that particular cylinder until the knock
disappears. It then advances the ignition to find the
optimum ignition timing for that cylinder. The ECM can
adjust the timing of each cylinder for knock
simultaneously. It is possible that all eight cylinders
could have different advance angles at the same time.
If the camshaft sensor fails, the knock sensor will
continue to work, but as the engine may be running
one revolution out of sychronisation the ECM may
retard the wrong cylinder of the pair e.g. 1 instead of
6. If the knock sensor fails engine knock will not be
detected and corrected. The fault is indicated by
illumination of the malfunction indicator light (MIL) on
North American specification vehicles.Ignition coils
The electronic ignition system uses four double ended
coils. They are mounted on a bracket fitted to the rear
of the engine. The circuit to each coil is completed by
switching within the ECM, allowing each coil to charge
up and fire. Sparks are produced in two cylinders
simultaneously, one on compression stroke, the other
on exhaust stroke. Note that coil 1 feeds cylinders 1
and 6, coil 2 feeds cylinders 5 and 8, coil 3 feeds
cylinders 4 and 7, and coil 4 feeds cylinders 2 and 3.
Due to the ease of combustion in the cylinder on the
compression stroke, more energy is dissipated in that
cylinder. Coil failure will result in a lack of sparks and
misfire in the affected cylinders. The fault is indicated
by illumination of the malfunction indicator light (MIL)
on North American specification vehicles.
Injectors
A multiport fuel injection system (MFI) is used, one
injector per cylinder. Each injector consists of a small
solenoid which is activated by the ECM to allow a
metered amount of fuel to pass into the combustion
chamber. Due to the pressure in the fuel rail and the
shape of the injector orifice, the fuel squirts into the
cylinder in a fine spray to aid combustion. In the
unlikely event of injector failure a misfire will occur as
there will be no fuel to the affected cylinder. The fault
is indicated by illumination of the malfunction indicator
light (MIL) on North American specification vehicles.

57STEERING
10
FAULT DIAGNOSIS VISUAL AND SAFETY CHECKS
WARNING: Before taking vehicle out on
the public highway for road test, it is
important that the following basic visual
checks are carried out to ensure that the vehicle
complies with legal requirements.
Tyres and wheel rims
1.Check and adjust tyre pressures.
See
GENERAL SPECIFICATION DATA,
Information, Tyre Pressures
Note that this information refers to standard tyres
fitted as original equipment.
2.Check condition of tyres. Inspect for signs of
uneven wear, damage and feathering. Check
tread depth.
3.Ensure that the tyre make, type and general
condition are common across each axle.
4.Check wheel rims for signs of damage and
excessive run out.
5.Carry out road test.
See Road Test Procedure
ROAD TEST PROCEDURE
General steering/handling problems can usually be
classified into one of the categories listed and ARE
GENERALLY RELATED TO THE AGE, CONDITION
AND USE OF THE VEHICLE.
WARNING: Ensure that all road tests are
conducted by suitably qualified drivers in
a safe and legal manner, and where local
traffic conditions allow.
1.Carry out visual and safety checks.
See Visual
and Safety Checks
Confirm general nature of complaint with customer,
simulating where possible the conditions under which
the problem occurs. Carry out following road test
procedure to establish the problem.2.Steering load assessment - drive at 16 km/h (10
mph). Put 90°turn input into steering wheel,
check self centering. The self centering should
be equal on each lock BUT not necessarily
return to exactly straight ahead without
assistance from the driver.
3.Steering assessment - drive at 64 km/h (40 mph)
on a staight FLAT road (no camber), check for
steering veer. The vehicle should follow a
straight path with NO tendency to follow a
curved path. If vehicle veers towards the kerb,
vehicle may be 'camber sensitive'. A small
amount of veer in direction of camber is
acceptable.
4.Directional stability assessment - drive at 112
km/h (70 mph) or maximum legal speed on a
straight flat road. Carry out a normal lane
change. Vehicle should quickly settle into a new
straight path.
5.Braking assessment (medium effort) - drive at 96
km/h (60 mph) on a straight flat road. Apply
steady medium braking effort, noting any
tendency to veer. Carry out brake test three
times, if a veer is consistently noted carry out a
braking efficiency test on a rolling road.
6.Braking assessment (full effort) - drive at 96
km/h (60 mph) on a straight flat road. Apply full
braking effort, noting any tendency to veer. Carry
out brake test three times, if a veer is
consistently noted carry out a braking efficiency
test on a rolling road.
If the symptom described by the customer is stiff
steering or steering niggle, carry out stiff steering
procedure.
See Stiff Steering Checklist
If not proceed with basic checks and adjustments.
See Visual Check and Basic Adjustments

86ELECTRICAL
10
DESCRIPTION AND OPERATION Radio frequency system
The RF system uses frequencies according to market
and both ECU and handset are colour coded:
Territory ECU/Handset............................... Frequency..................
Europe Blue/Blue.................................. 433.92 MHz.........................
NAS Green/Green....................................... 315.00 MHz....................
Japan Green/Green.................................... 315.00 MHz....................
Gulf Green/Green....................................... 315.00 MHz....................
Rest of World Green/Brown........................ 315.00 MHz...................
NOTE: In service NAS, Japan and Gulf will
have the handset changed to brown.
Passive coil
The passive coil excites a receiving coil in the handset
causing it to automatically transmit a remobilisation
signal to the ECU.
Inertia switch and central door locking
Actuation of the inertia switch will cause the doors to
be unlocked. A time-out period (programmable
between 0-5 minutes) will ensue, during which all CDL
and alarm activity is disabled.
NOTE: This feature only applies when the
starter switch is in the on position.
Handset
Under normal circumstances pressing the respective
buttons on the handset once, will unlock or lock the
vehicle. If operating the handset does not achieve the
desired effect
See Repair, Handset.
Functional detail
For full functional details and circuit diagrams
See
Electrical Trouble Shooting Manual..
Vehicle traceability
All Land Rover vehicles are fitted with a multitude of
discreet security features to prevent theft or assist
recovery in the event of a vehicle being stolen. All
vehicles are traceable, since it is impossible to
remove all security identification.