ignition LAND ROVER DISCOVERY 1995 Repair Manual

19FUEL SYSTEM
10
DESCRIPTION AND OPERATION
Driving
When the throttle pedal is depressed, the ECM
implements the cruise air/fuel ratio map. During
driving the ECM continually monitors inlet air
temperature and engine speed and load for it's air
flow calculations, together with coolant temperature
for any temperature corrections. Additional inputs are
throttle potentiometer for acceleration and throttle
pedal switch for cruise/idle fuel map selection and
over-run fuel cut-off.
Acceleration enrichment
When the throttle pedal is depressed, the ECM
receives a rising voltage from the throttle
potentiometer and detects a rise in manifold pressure
from the manifold absolute pressure sensor. The ECM
provides additional fuel by increasing the normal
injector pulse width and also provides a small number
of extra injector pulses on rapid throttle openings.
Over-run fuel cut-off
The ECM implements over-run fuel cut-off when the
following signals are received.
·Throttle disc closed.
·Engine speed is above 2000 rev/min - engine at
normal operating temperature.
Fuel is reinstated progressively when any of the
above signals cease.
Over-speed fuel cut-off
To prevent damage at high engine speeds the ECM
inhibits the earth path for the injectors, cutting off
injection. As engine speed falls, injection is reinstated.
Ignition switch off
When the ignition is switched off, the ECM will keep
the main relay energised for approx. 30 seconds while
it drives the stepper motor to the 35 step position for
the next engine start.

Mpi
1
ADJUSTMENT THROTTLE CABLE
Adjust
NOTE: Use diagnostic equipment to
ensure that the throttle potentiometer and
stepper motor are synchronised before
adjusting the throttle cable.
Ensure that the cable is correctly routed and located.
1.Switch ignition on, wait 5 seconds and switch
ignition off to ensure stepper motor is in setting
position.
2.Loosen throttle cable adjustment nut and locknut
from abutment bracket.
3.Hold cam in "throttle closed" position and rotate
cable adjustment nut until a gap of 2mm exists
between the nut and abutment bracket.
4.Tighten cable locknut to contact abutment
bracket.
5.Using two wrenches tighten nuts onto abutment
bracket.
6.Operate throttle pedal and ensure throttle opens
fully.

Mpi
1
REPAIR KNOCK SENSOR
Service repair no - 18.30.18
Remove
1.Disconnect multiplug from knock sensor.
2.Remove knock sensor.
Refit
3.Clean mating face of cylinder block.
4.Fit knock sensor. Tighten to
15 Nm
5.Connect multiplug.IGNITION COILS
Service repair no - 18.20.40 - 1 & 4 Cylinders
Service repair no - 18.20.41 - 2 & 3 Cylinders
Remove
1.Disconnect battery negative lead.
2.Disconnect 4 h.t. leads from coils.
NOTE: Mark the position of the h.t. leads
to ensure correct refitment.
3.Disconnect 2 multiplugs from coils.
4.Disconnect crankshaft sensor multiplug.
5.Remove screw securing crankshaft sensor
multiplug to coil bracket.
6.Remove 3 bolts securing coil bracket to bell
housing.
NOTE: Access to the rear bolts is from
under the vehicle.
7.Remove coil assembly.
Refit
8.Position coil assembly to bell housing.
9.Fit 3 bolts and tighten to the correct torque.
10.Secure crankshaft sensor multiplug to coil
bracket with screw.
11.Connect crankshaft sensor multiplug.
12.Connect multiplugs and h.t. leads to coils.
13.Reconnect battery negative lead.

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.

V8i
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, Drive Belt -
Check Tension
YES - Continue.
3.Is ignition timing correct?
NO -
See ELECTRICAL, Adjustment,
Ignition Timing
YES - Continue.
4.Is coolant in radiator frozen?
YES - Slowly thaw and drain system.
See
Adjustment, Coolant Requirements
NO - Continue.
5.Is air flow through radiator restricted or blocked?
YES - Apply air pressure from engine side of
radiator to clear obstruction.
NO - Continue.
6.Are there any external leaks, from water pump,
engine gaskets or the heater unit?
YES - Investigate and rectify.
See Adjustment,
Coolant Requirements
NO - Continue.
7.Are fan blades fitted correct way round, concave
side towards engine?
NO - Rectify.
YES - Continue.8.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 11,
otherwise: Continue.
9.Are the air conditioning fans operating correctly?
See Electrical Trouble Shooting Manual.K5
NO - Rectify.
YES - Continue.
10.Is temperature sender and gauge giving
accurate readings?
NO - Substitute parts and compare readings.
YES - Continue.
11.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 the coolant only, or both systems are contaminated,
suspect cylinder head gaskets or radiator.
If only the lubrication stystem is contaminated with
coolant, suspect inlet manifold or front cover gaskets.

TRANSFER GEARBOX
1
DESCRIPTION AND OPERATION LT230T TRANSFER BOX
The LT230T transfer box is a permanent 4 wheel
drive, two speed ratio reducing gearbox incorporating
high and low range outputs with mechanically lockable
centre differential (diff-lock). High/low range and
diff-lock selection are made via a single lever located
forward of the main gear lever.
A shiftlock device is fitted in some territories, it is used
as a park facility and prevents accidental gear
disengagement when the ignition is switched off. An
audible neutral alarm is also fitted. This alerts the
driver when parking to move the gear lever to the high
or low position.

STEERING
3
DESCRIPTION AND OPERATION Steering column components
1. Upper shroud
2. Column harness
3. Cruise control switch (if fitted)
4. Steering wheel and nut
5. Rotary coupler
6. Column switch
7. Shear bolts
8. Switch saddle
9. Upper steering column
10. Universal joint
11. Universal joint bolt
12. Steering column lock assembly13. Lower shroud
14. Column lock/ignition
15. Air bag mounting bracket (if fitted)
16. Air bag module
17. Steering pad (non-airbag)
18. Lower shaft
19. Rubber coupling
20. Compression joint
21. Universal joint
22. Universal joint bolt

57STEERING
12
REPAIR UPPER STEERING COLUMN
Service repair no - 57.40.01
NOTE: Steering column assembly is not a
serviceable component.
CAUTION: Before removing any parts of
steering linkage, it is imperative that road
wheels are positioned straight ahead. then
steering wheel removed to prevent rotary coupler
being wound up or damaged.
CAUTION: After refitting steering linkage
parts follow correct procedure to ensure
that road wheels, steering box and
steering wheel are correctly positioned relative to
each other when in straight ahead condition. if
steering wheel requires repositioning, ensure that
drive pegs on rotary coupler are correctly
positioned before steering wheel is replaced.
This ensures drive pegs locate in their holes in
rear of steering wheel.
After final alignment, connect rotary coupler
multiplug, tighten steering wheel securing nut and
fit airbag - if fitted or steering wheel trim pad and
horn push assembly.
Remove
1.Remove steering wheel.
See Steering Wheel
CAUTION: Prevent rotation of rotary
coupler once steering wheel is removed.
Secure in position with adhesive tape.
2.Remove driver's access panel.
3.Remove steering column shroud.
See Steering
Column Shroud
4.Remove rotary coupler.See
SUPPLEMENTARY RESTRAINT SYSTEM,
Repair, Rotary Coupler
5.If fitted - remove 4 screws securing knee bolster,
remove knee bolster.
6.Disconnect column switch multiplug.
7.Disconnect ignition switch multiplug from fuse
box.

STEERING
13
REPAIR
8.Disconnect ignition switch main feed multiplug.
9.Remove 4 nuts securing upper column to lower
mounting.
10.Remove 2 nuts securing lower mounting steady
bracket, remove bracket.
11.Remove pinch bolt securing upper column to
universal joint.
12.Remove 2 nuts and washes securing upper
column to upper mounting bracket.13.Carefully manoeuvre upper column out of
footwell, recover rubber boot.
NOTE: Do not carry out further
dismantling if upper column is removed
for access only.
14.Loosen but, do not remove screw securing
column switch assembly, withdraw assembly to
gain access to multiplugs.
15.Disconnect column switch multiplugs, remove
column switch assembly.
16.Disconnect ignition switch multiplug.
17.Remove shear bolts securing steering column
lock, remove lock and saddle; discard shear
bolts.
18.Withdraw bulb holder from column lock shroud.
19.Transfer components to new upper column,
connect multiplug.
NOTE: Do not shear column lock bolts at
this stage.

57STEERING
14
REPAIR Refit
20.Manoeuvre upper column to position in footwell,
ensure splines in column and universal joint are
correctly engaged and rubber boot is fitted.
21.Fit but do not tighten universal joint pinch bolt.
22.Position upper column to upper mounting, fit
washers and nuts, do not tighten nuts.
23.Fit but do not tighten nuts and bolts securing
upper column to lower mounting.
24.Fit lower mounting steady bracket, fit but do not
tighten nuts and bolts.
25.Ensure upper column is aligned to mountings.
26.Tighten all nuts and bolts to
22 Nm.
27.Tighten universal joint pinch bolt to25 Nm.
28.Connect column switch multiplug.
29.Connect ignition switch multiplugs.
30.Fit rotary coupler.
See SUPPLEMENTARY
RESTRAINT SYSTEM, Repair, Rotary
Coupler
31.Fit steering wheel.See Steering Wheel
32.Reconnect battery negative lead.
33.Check steering column lock for correct
operation, tighten shear bolts until heads shear
off.
34.If fitted - position knee bolster, fit and tighten
screws.
35.Fit steering column shroud.
See Steering
Column Shroud
36.Fit driver's access panel.