battery LAND ROVER DISCOVERY 1995 Owners Manual

19FUEL SYSTEM
28
REPAIRADD: 09/95 Refit
26.Fit vent line to filler neck.
27.Fit NEW clip to filler neck hose.
28.Fit hose to filler neck.
29.Position filler neck hose clip and tighten until
head shears.
30.Fit filler neck assembly to vehicle.
NOTE: To aid fitment of filler neck through
body grommet apply a soap solution to lip
of grommet.
31.Fit NEW clip to fuel filler neck hose.
32.Connect fuel filler neck internal breather to tank.
33.Connect fuel filler neck hose to tank.
34.Position fuel filler neck hose clip and tighten until
head shears.
35.Connect vent line quickfit connector to
liquid/vapour separator.
36.Connect the pressure sensor breather pipe
connection.
37.Connect the vent line hose connection.
38.Fit mud flap and secure with nuts and bolts.
39.Position filler neck support bracket and earth
strap to mud flap bracket and secure with nut
and bolt.
40.Remove stand(s) and lower vehicle.
41.Reposition loadspace sound insulation and
carpet.
42.Fit RH luggage compartment side panel.
See
CHASSIS AND BODY, Repair,
43.Fit tail door tread strip and secure with screws.
44.Refill tank with drained fuel.
45.Fit fuel filler cap to filler neck.
46.Close filler flap, lock with ignition key and
remove key.
47.Reconnect battery negative lead.FUEL TANK FILLER CAP - ADVANCED EVAPS
Service repair no - 19.55.08
Remove
1.Fit ignition key to fuel filler flap lock and open
flap.
2.Remove screw securing cap retaining strap to
body.
3.Remove fuel filler cap.
Refit
4.Fit fuel filler cap.
5.Position cap retaining strap to body and secure
with screw.
6.Close filler flap, lock with ignition key and
remove key.

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

Mpi
9
DESCRIPTION AND OPERATION SYSTEM OPERATION
Ignition on
When the ignition is switched on, voltage is applied to
ECM pin 11. The ECM then switches on the main
relay by supplying an earth path at pin 4. This allows
battery voltage to pass to ECM pin 28, to the four
injectors and through the ignition coil to ECM pin 25.
In addition, the fuel pump relay is switched on by the
ECM supplying an earth path on pin 20. Voltage is
applied through the inertia switch to the fuel pump.
The pump runs for a short period to pressurise the
fuel rail. The fuel pressure regulator will open at its
maximum setting and excess fuel is spill returned to
the tank.
The ECM determines the amount of stepper motor
movement from the following signals:
·Engine coolant temperature data at pin 33.
·Inlet air temperature data at pin 16.
·Throttle potentiometer data at pin 8.
·Engine speed data at pins 31 and 32.
·Manifold absolute pressure data (via pipe from
manifold).
·Battery voltage at pin 28.
·Ignition signal at pin 11.
If one or more of the following inputs fail, the ECM will
substitute the back-up values shown to maintain
driveability.
Input Back-up value
Coolant temperature Idle Speed controlled until
engine is fully warm. 60°Cat
speeds above idle.
Inlet air temperature Derived from engine speed and
engine load.
Manifold absolute Derived from engine speed and
pressure throttle position.
Starter operation
Whilst the starter relay is energised, battery voltage is
applied to the starter motor solenoid. The solenoid
also energises and supplies battery voltage directly to
the starter motor.
Ignition is controlled by the ECM switching the low
tension circuit via pin 25.
The ECM provides an earth signal on pins 24, 23, 26
and 1 for the period the injectors are required to be
open, the injector solenoids are energised
(simultaneously on naturally aspirated models) and
fuel is sprayed into the manifold onto the back of the
inlet valves. The ECM carefully meters the amount of
fuel injected by adjusting the injector opening period
(pulse width). During cranking, when the engine
speed is below approx. 400 rev/min, the ECM
increases the injector pulse width to aid starting. The
amount of increase depends upon coolant
temperature. To prevent flooding, injector pulses are
intermittent i.e. 24 on then 8 pulses off.
Idling
After start enrichment is provided at all temperatures
immediately cranking ceases. The ECM controls the
enrichment by increasing injector pulse width. The
enrichment decays in relation to the rising coolant
temperature.
Provided the ECM is receiving a signal that the engine
speed is close to the idle speed set point, the ECM
will implement idle speed control.
The ECM activates a unipolar stepper motor acting
directly on the throttle lever. Idle speed response is
improved by the ignition system advancing or
retarding the timing when load is placed on, or
removed from the engine.
If, during engine idle, the load on the engine is
increased sufficiently to cause engine speed to fall,
the ECM will sense this via the crankshaft sensor and
instantly advance the ignition timing to increase idle
speed and then energise the stepper motor to open
the throttle disc thus maintaining the idle speed.
Finally the ignition timing is retarded to its nominal
value.
The ECM monitors battery voltage and, if voltage falls
sufficiently to cause fluctuations in injector pulse
widths, it increases the injector pulse widths to
compensate.
On return to idle, the ECM will implement a slightly
higher idle speed to prevent the engine stalling.

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.

Mpi
9
REPAIR
Refit
9.Examine flexible mounting for splits or damage;
renew as necessary.
10.Thoroughly clean throttle housing and mating
face of flexible mounting.
11.Connect breather hose to throttle housing.
12.Position throttle housing to mounting studs, fit
nuts. Tighten to
7 Nm.
13.Connect throttle cable to cam.
14.Adjust throttle cable.
15.Connect multiplug to stepper motor.
16.Connect multiplug to throttle potentiometer.
17.Connect hose to throttle housing, tighten clip.FUEL PRESSURE REGULATOR
Service repair no - 19.45.06
Remove
1.Disconnect battery negative lead.
2.Position absorbant cloth around fuel pipe to fuel
rail union. Loosen bolt to relieve pressure.
Re-tighten bolt.
3.Release clip and disconnect fuel hose from
pressure regulator.
CAUTION: Plug the connectors.
4.Disconnect intake air temperature sensor
multiplug.
5.Remove 4 bolts securing pressure regulator
steady bracket to fuel rail and manifold, remove
steady bracket.
6.Disconnect vacuum hose from pressure
regulator.
7.Manoeuvre pressure regulator from fuel rail.
8.Discard 'O' ring.

19FUEL SYSTEM
10
REPAIR
Refit
9.Clean pressure regulator and mating surfaces.
10.Fit new 'O' ring to pressure regulator.
11.Fit vacuum hose to pressure regulator.
12.Position pressure regulator.
13.Fit steady bracket.
14.Fit bolts and tighten.
15.Connect multiplug to air temperature sensor.
16.Remove plugs, fit fuel hose to regulator and
secure with clip.
17.Reconnect battery negative lead.OXYGEN SENSOR
Service repair no - 18.30.41 - L.H
Service repair no - 18.30.42 - R.H
Remove
1.Disconnect oxygen sensor multiplug.
2.Release multiplug from bracket.
3.Release harness lead from cable tie.
4.Remove oxygen sensor; recover sealing washer.
Refit
5.Fit sealing washer to oxygen sensor.
6.Fit oxygen sensor. Tighten to
55 Nm.
7.Secure multiplug to bracket, connect multiplug.
8.Secure harness lead with cable tie.

19FUEL SYSTEM
2
REPAIR ENGAGEMENT (ON/OFF) SWITCH
Service repair no - 19.75.30
Switch Replacement
Remove
1.Disconnect battery negative lead.
2.Carefully release auxiliary switch panel from
fascia.
3.Disconnect multiplug from switch.
4.Depress retaining lugs on switch, remove switch
from panel.
Bulb replacement
5.Position switch to facilitate removal of bulb.
6.Rotate bulb holder 90°and withdraw it from
switch.CRUISE CONTROL SWITCH
Service repair no - 19.75.36
Remove
1.Disconnect battery negative lead.
2. Models fitted with airbags:Remove driver's
airbag module.
See SUPPLEMENTARY
RESTRAINT SYSTEM, Repair, Driver's
Airbag Module
3. Models without airbags:Turn steering wheel
through 90°. Remove 2 Torx screws securing
pad to steering wheel and remove steering
wheel pad.
4.Disconnect cruise control switch multiplug from
main harness.

CRUISE CONTROL
3
REPAIR
5.Disconnect 2 Lucars from horn contacts.
6.Remove 2 screws securing cruise control switch
to steering wheel.
7.Remove 3 bolts securing mounting bracket to
steering wheel and remove mounting bracket.
8.Remove cruise control switch from steering
wheel.
Refit
9.Reverse removal procedure. Ensuring wiring
harness is routed correctly.
10. Models fitted with airbags:Refit driver's airbag
module and follow all safety precautions.
See
SUPPLEMENTARY RESTRAINT SYSTEM,
Repair, Driver's Airbag Module
ROTARY COUPLER
Service repair no - 19.75.54
The rotary coupler is located behind the steering
wheel. Access is gained by removing the steering
wheel and steering column shroud.
NOTE: On vehicles fitted with airbags.See
SUPPLEMENTARY RESTRAINT SYSTEM,
Repair, Rotary Coupler
Remove
1.Disconnect battery negative lead.
2.Remove steering wheel.
See STEERING,
Repair, Steering Wheel
3.Release 2 turnbuckles securing lower dash
closing panel and lower.
4.Remove 3 screws securing lower half of shroud
to steering column.
5.Disconnect rotary coupler multiplug from
steering column harness.

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.

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.