oil change LAND ROVER DISCOVERY 1995 User Guide

Mpi
3
DESCRIPTION AND OPERATION Fuel system
ECM
The MEMS system is controlled by the ECM which is
located in the engine compartment.
The ECM is an adaptive unit and can learn the load
and wear characteristics of a particular engine.
The ECM remembers and updates two main engine
requirements when the engine is fully warm:
1.The idle stepper position required to achieve the
specified idle speed.
2.The fuelling change or offset required to achieve
a set oxygen sensor voltage.
The stepper position is used as a reference to update
the amount of stepper motor movement required to
achieve the specified idle speed under all conditions.
The fuelling offset is required to enable the system
when not in closed loop control to provide the correct
fuelling and while in closed loop control to prevent
having to apply excessive adjustments to the fuelling
which can adversely affect the emissions and
driveability.
NOTE: After fitting a different ECM, a full
tune procedure must be carried out using
Testbook.
The ECM inputs and outputs are shown in the table.INPUTS TO MEMS ECM
Crankshaft sensor
Manifold absolute pressure
Coolant temperature sensor
Inlet air temperature sensor
Knock sensor
Oxygen sensor
Throttle potentiometer
Throttle closed
Battery supply
Ignition supply
Diagnostic input
Power earth
Sensor earth
Fuel temperature sensor
Oxygen sensor
Air conditioning switch
OUTPUTS FROM MEMS ECM
Ignition coil
Injectors
Aircon relays
Stepper motor
Temperature gauge
Fuel pump relay (inside relay module)
Main relay (inside relay module)
Diagnostic output

19FUEL SYSTEM
4
DESCRIPTION AND OPERATION
Injectors
The four fuel injectors are fitted between the
pressurised fuel rail and inlet manifold. Each injector
comprises of a solenoid operated needle valve and a
specially designed nozzle to ensure good fuel
atomisation.
Engine coolant temperature sensor
The coolant temperature sensor is mounted in the
thermostat housing and is immersed in the engine
coolant. The sensor is a resistive device in which the
resistance varies with temperature
Throttle housing
The throttle housing is attached to the inlet manifold
via a rubber sandwich plate and incorporates a throttle
disc which is connected to the throttle pedal via the
throttle lever and a cable.
There are two breather pipes; one either side of the
throttle disc. When the engine is running with the
throttle disc open, both pipes are subject to manifold
depression and draw crankcase fumes into the
manifold. When the throttle disc is closed, only the
pipe on the inlet manifold side of the disc is subject to
manifold depression. This pipe incorporates a
restrictor to prevent engine oil being drawn into the
engine by the substantially greater manifold
depression.
Also incorporated in the throttle housing are the
throttle potentiometer and stepper motor.
Throttle potentiometer
The throttle potentiometer is mounted in front of the
throttle housing and is directly coupled to the throttle
disc shaft.
Three wires connect the throttle potentiometer to the
ECM; a 5 volt supply to the potentiometer, an earth
return to the ECM and an output voltage to the ECM
which indicates the rate of throttle disc movement.
Stepper motor
The stepper motor is contained within the throttle
housing and operates a cam and push rod via a
reduction gear. The push rod is in direct contact with
the throttle lever and moves the throttle disc to control
idle and fast idle speed. The stepper motor maximum
movement is 3.75 revolutions accomplished in steps
of 7.5°. The reduction gear converts this into 180°of
cam movement.
The throttle lever has a throttle position setting screw
which rests on the stepper motor operating pin when
the throttle pedal is released and is used to set the
relationship between engine speed and stepper motor
position.
In the side of the throttle housing is a throttle air
bypass bleed screw to provide easier and more
sensitive setting of the stepper motor position at idle.
The stepper motor position is checked using Testbook
and should be within the range of 20 to 40 steps when
the engine is run in. If it is identified as being outside
this range it can be adjusted to within range by turning
the throttle air bypass bleed screw. It is important to
follow Testbook setting procedure when adjusting this
screw to prevent mismatching of throttle body
settings. This ensures that the stepper motor is at the
optimum position within its range for providing further
movement to compensate for changes in engine load
or temperature in accordance with signals from the
ECM
NOTE: The stepper motor and throttle
position setting screws must only be
adjusted when Testbook identifies the
requirement.

33CLUTCH
2
FAULT DIAGNOSIS FAULT/SYMPTOM CHART
Symptoms
Slip Spin/Drag Judder/Fierce Fault Item
* * * Worn or oil on clutch linings 2
* * * Mechanical damage45678
* * Distorted clutch plate 2
* Failed or air in hydraulic system 12 13
* * Primary shaft tight fit in crankshaft bush 15 17
* Clutch splines sticking 2 15
* Weak clutch plate springs or insecure/worn
engine/gearbox mountings6
* Insecure/worn propeller shafts
* Insecure/worn suspension components/rubber
bushes
For items refered to in this chart.See Description and operation, Description
CLUTCH NOISE - MECHANICAL FAULTS
Noise from clutch or gearbox in neutral, which
disappears when clutch is depressed.
Suspect gearbox input/primary shaft bearings.
See MANUAL GEARBOX, Fault diagnosis,
Manual Gearbox
- Noise from gearbox in neutral, which
disappears when clutch is depressed
Noise from clutch or gearbox in neutral, which
changes tone or becomes worse when the clutch
is depressed.
Suspect worn release bearing.
Knocking/rattling from clutch or gearbox in
neutral, which is reduced or disappears when the
clutch is depressed.
Suspect worn/weak release lever retainer or
clutch unit.
Noise from clutch or gearbox in neutral, which
disappears when clutch is depressed.
Suspect gearbox fault.
See MANUAL GEARBOX, Fault diagnosis,
Manual Gearbox
- Noise from gearbox in neutral, which
disappears when clutch is depressed.HYDRAULIC FAULTS
Unable to dis-engage clutch, little or no pedal
resistance.
1.Check condition, specification and level of fluid.
2.Check pipes and cylinders for leaks.
3.Check that air vent in reservoir lid is clear.
Suspect faulty master cylinder if no fluid leaks
present.
See Repair, Master Cylinder
Spongy pedal operation
1.Check condition, specification and level of fluid.
2.Check that air vent in reservoir lid is clear.
Suspect air in fluid.
See Repair, Bleed Hydraulic System
Clutch is difficult to dis-engage and/or does not
immediately re-engage when pedal is released.
1.Check condition, specification and level of fluid.
2.Check that air vent in reservoir lid is clear.
Suspect pedal pivot, master cylinder or slave
cylinder seizure.
See Repair, Master Cylinder

R380
1
DESCRIPTION AND OPERATION MANUAL TRANSMISSION
Description
The all synchromesh five speed manual gearbox unit,
is married to a LT230T two speed transfer gearbox.
All the gears including reverse run on needle roller
bearings and the main, layshaft and primary shafts
are supported by tapered roller bearings.The whole of the geartrain is lubricated through
drillings in the shafts, supplied by a low pressure
pump driven from the rear of the layshaft. The gear
change has a single rail selector and spool type
interlock. The main and transfer gearboxes ventilate
through nylon pipes, which terminate high up in the
engine compartment to prevent water entry when the
vehicle is operating in adverse conditions.
1. Mainshaft 1st gear
2. Mainshaft 2nd gear
3. Mainshaft 3rd gear
4. Primary input shaft
5. Mainshaft 5th gear
6. Layshaft
7. Mainshaft
8. Lubrication pump9. Drain plug
10. Ventilation pipe
11. Single rail gear shift
12. 1st/2nd synchromesh
13. Oil seals
14. 3rd/4th synchromesh
15. 5th gear synchromesh

TRANSFER GEARBOX
1
SPECIFICATIONS, TORQUE TORQUE VALUES
NOTE: Torque wrenches should be regularly checked for accuracy to ensure that all fixings are
tightened to the correct torque.
Nm
LT230T Transfer gearbox
Pinch bolt - operating arm to crank arm 9......................................................
End cover gear change housing 9.................................................................
Bottom cover to transfer case 25....................................................................
Front output housing to transfer case 25........................................................
Cross shaft housing to front output housing 25...............................................
Gear change housing 25.................................................................................
Pivot shaft to link arm 25.................................................................................
Connecting rod to adjustable clevis 25...........................................................
Anti-rotation plate intermediate shaft 25.........................................................
Front output housing cover 25........................................................................
Pivot bracket to extension housing 25............................................................
Finger housing to front output housing 25......................................................
Bearing housing to transfer case 25...............................................................
Brake drum to coupling flange 25...................................................................
Bearing housing cover to transfer gearbox 45................................................
Rear output speedometer housing to transfer gearbox 45..............................
Selector finger to cross shaft high/low 25.......................................................
Selector fork, high/low to shaft 25...................................................................
Transmission brake to speedometer housing 72............................................
Gate plate to grommet plate 9.......................................................................
Gearbox to transfer case 45...........................................................................
Oil drain plug 30..............................................................................................
Oil filler/level plug 30.......................................................................................
Differential case (front to rear) 60...................................................................
Output flanges 162...........................................................................................
Differential case rear stake nut 72..................................................................
Transfer breather 15.......................................................................................
Transfer box front drive flange to drive shaft 45..............................................
Transfer box rear drive flange to drive shaft 45..............................................
Transfer gearbox mounting brackets to chassis 30........................................
Mounting brackets to transfer gearbox 55......................................................
Mounting rubbers to mounting brackets 21.....................................................
Shiftlock
Shiftlock screws 9..........................................................................................
Neutral switch 25............................................................................................

REAR AXLE AND FINAL DRIVE
1
OVERHAUL AXLE DIFFERENTIAL ASSEMBLY
Service repair no - 51.15.07.
DISMANTLE
NOTE: Mark differential components so
their original positions relative to other
components is maintained. Bearing caps
must not be interchanged.
1.Remove axle shafts then differential assembly
fom axle.
2.Remove roll pin securing bearing nut locking
fingers to bearing caps. Remove locking fingers.
3.Loosen bearing cap bolts and mark caps for
assembly.
4.Using service tool LRT-54-508, remove bearing
adjusting nuts.
5.Remove bearing cap bolts and bearing caps.
6.Remove crown wheel differential unit and
bearings.
Remove pinion FRONT AXLE DIFFERENTIAL
ONLY
7.Remove pinion flange nut using service tool
LRT-51-003 to restrain flange.
8.Remove washer and pinion drive flange.
9.Remove pinion complete with bearing and outer
bearing shims.
10.Remove pinion flange oil seal, spacer and
bearing.
Remove pinion REAR AXLE DIFFERENTIAL ONLY
7.Remove pinion flange centralizing peg using
service tool LRT-51-008.
8.Remove pinion flange nut using service tool
LRT-51-003 to restrain flange.
9.Remove pinion complete with bearing and outer
bearing shims.
10.Remove pinion flange oil seal and bearing.
11.Using service tool LRT-54-505, remove pinion
head bearing track and shim and drive out outer
bearing of differential housing.

51REAR AXLE AND FINAL DRIVE
6
OVERHAUL 48.Repeat on other bearing bore. Add readings
then halve sum to obtain mean reading. Note
whether trace pin has moved up or down from
zero.
A. Where trace pin moves down, reading is
equal to thickness of shims to remove, to
bring pinion to nominal.
B. Where trace pin moves up, reading is
equal to thickness of shims to add, to bring
pinion to nominal.
49.Before adjusting shim thickness: check pinion
face marking. If a plus (+) figure, subtract in
thousandths of an inch from shim thickness
figure.
50.If pinion has a minus (-) figure, add amount to
shim thickness figure.
Adjust shim thickness under pinion head bearing
track as necessary.
INCH MM
.001 = .025
.002 = .05
.003 = .075
.004 = .10
.005 = .125
.006 = .15
.007 = .175
.008 = .20
.009 = .225
.010 = .25
NOTE: Where dial indicator is metric
conversion must be made to inches when
measuring and selecting shims.
51.Recheck pinion height setting. If setting is
correct, mean reading of dial gauge will agree
with figure marked on pinion end face.
For example, with end face marking of +3, dial
gauge reading should indicate pinion is +0.003
in.Bearing pre-load adjustment
52.Remove the pinion flange, pinion, outer bearing
and spacer.
53.Slide new shim, of same thickness as original
(bearing pre-load) into position on pinion shaft. If
fitting a new shim use thickest shim 2.155 mm.
54.Fit pinion to pinion housing and fit outer bearing
and spacer (front differential only).
55.Fit driving flange, washer and nut.
56.Do not fit oil seal at this stage.
57.Tighten pinion flange nut to130 Nm.Force to
rotate pinion shaft is 3Nm using new bearings.
Change shim as necessary to obtain reading.
Thicker shim will reduce pre-load. Thinner shim
will increase pre-load.
NOTE: If using original bedded in
bearings, pre-load figure is 1.5 Nm.
58.Remove pinion flange.

57STEERING
8
FAULT DIAGNOSIS 4. DIRECTIONAL STABILITY
From 1. GENERAL STEERING:
1.Is directional stability concern when vehicle is
towing?
YES - Check towing/vehicle loading parameters
in Owner's Handbook.
NO - go to 3.
2.Is problem resolved?
YES - end
NO - continue.
3.Check condition of rear trailing link/chassis
bushes.
4.Is problem resolved?
YES - end
NO - continue.
5.Check condition of front and rear shock
absorbers. If in doubt change units in pairs, side
to side.
6.Is problem resolved?
YES - end
NO - continue.
7.Check steering damper.
See Steering Damper
8.Is problem resolved?
YES - end
NO - continue.
9.Check wheel balance
10.Is problem resolved?
YES - end
NO - contact local technical office.POWER STEERING FLUID LEAKS
1.Is fluid level correct?
YES - go to 3.
NO - Refill or drain to correct level. Bleed
system, check for leaks.
See Repair,
Power Steering System - Bleed
2.Is problem resolved?
YES - end
NO - continue.
3.Are hoses or joints leaking? Check on full lock
with engine at 2000 rev/min.
YES - loosen and retorque joints.
NO - go to 6.
4.Does leak remain?
YES - change PAS pipe.
NO - end.
5.Does leak remain?
YES - suspect seal in component. Check and
replace as necessary.
NO - end.
6.Is oil escaping from filler cap?
YES - bleed system.
See Repair, Power
Steering System - Bleed
NO - go to 8.
7.Is oil still escaping from filler cap?
YES - go back to 1.
NO - end.
8.Is oil leaking from PAS pump?
YES - go to 10.
NO - continue.
9.Is oil leaking from PAS box?
YES - go to 10.
NO - end.
10.Clean unit, add tracer dye to system. Retest
11.Is oil still leaking?
YES - establish leak point. Repair or replace
unit as necessary.
NO - end.

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.

86ELECTRICAL
4
FAULT DIAGNOSIS TEST 4:
Pick-up Coil Resistance
Remove amplifier.
Connect ohmmeter leads to two pick-up terminals in
body of distributor.
The ohmmeter should register between 2k and 5k
ohm if pick-up is satisfactory. If ohmmeter reading is
correct, check all connections between pick-up and
amplifier, if satisfactory, fit new amplifier. If engine still
does not start carry out Test 5.
Change pick-up if ohmmeter reading is incorrect. If
engine still does not start proceed to Test 5.TEST 5:
Coil H.T. Sparking
Remove existing coil/distributor H.T. lead and fit test
H.T. lead to coil tower. Using suitable insulated pliers,
hold free end about 6mm from engine block and crank
engine. There should be good H.T. sparking.
If weak or no sparking, fit new coil, repeat test.
H.T. sparking good, repeat test with original H.T. lead.
If sparking is good carry out Test 6.
If weak or no sparking, fit new H.T. lead, if engine will
not start carry out Test 6.