1995 LAND ROVER DISCOVERY check engine

SFI
1
ADJUSTMENT ENGINE TUNING
Service repair no - 19.22.13
The position of the Idle Air Control (IAC) valve can be
checked using TestBook and adjusted if necessary
through the by-pass screw in the plenum chamber.
The bypass screw is covered by a tamper proof plug
which can be extracted using a self tapping screw.
All vehicles:
1.Ensure air conditioning and all electical loads are
off. Vehicle must be in neutral or park with air
suspension in kneel and disabled.
2.Carry out tuning or base idle setting procedure
as applicable using TestBook.

19FUEL SYSTEM
2
REPAIR ENGINE COOLANT TEMPERATURE SENSOR (ECT
SENSOR)
Service repair no - 18.30.10
Remove
1.Disconnect battery negative lead.
2.Remove spring clip and disconnect ECT sensor
multiplug.
3.Position cloth around ECT sensor to absorb
coolant spillage.
4.Remove ECT sensor.
5.Remove sealing washer and discard.
Refit
6.Clean sealing washer, sensor threads and
sensor location.
7.Coat sensor threads with Loctite 577 and fit new
sealing washer.
8.Fit ECT sensor. Tighten to
20 Nm.
9.Fit spring clip to multiplug and connect multiplug
to ECT sensor.
10.Top up cooling system.
11.Run engine to normal operating temperature.
Check for leaks around ECT sensor.CRANKSHAFT POSITION SENSOR (CKP SENSOR)
Service repair no - 18.30.12
Remove
1.Disconnect battery negative lead.
2.Raise vehicle on ramp.
3.Remove 2 bolts securing sensor/shield to engine
backplate.
4.Remove sensor/shield.
5.Remove shield.
6.Disconnect sensor multiplug and remove sensor.
7.Remove spacer from sensor.
CAUTION: All vehicles have a spacer fitted
to the sensor. Ensure spacer is correctly
refitted.
Refit
8.Clean mating faces.
9.Fit spacer to sensor.
10.Position sensor and connect multiplug.
11.Position shield to sensor and align sensor/shield
to engine backplate.
12.Fit bolts. Tighten to
6 Nm.
13.Lower ramp.
14.Reconnect battery negative lead.

19FUEL SYSTEM
6
REPAIR 15.Disconnect hose, plug return hose and rail.
Remove cloth.
16.Remove 6 nuts securing fuel rail and ignition coil
bracket to inlet manifold.
17.Release ignition coil bracket from inlet manifold
studs. Place aside.
18.Release fuel rail and injectors from inlet
manifold.
Do not carry out further dismantling if component
is removed for access only.
19.Remove fuel rail and injectors.
20.Remove 2 bolts securing fuel pressure regulator
to fuel rail.
21.Remove pressure regulator assembly.
22.Remove 'O' ring from fuel pressure regulator and
discard.
23.Remove 8 clips securing injectors to fuel rail.
24.Remove injectors from fuel rail.
25.Remove 2 'O' rings from each injector and
discard.Refit
26.Ensure mating surfaces between inlet manifold
and ram pipe housing are clean.
27.Ensure all locations in fuel rail and inlet manifold
are clean.
28.Lubricate and fit new 'O' rings to injectors and
fuel pressure regulator.
29.Fit fuel pressure regulator to fuel rail. Secure
with bolts. Tighten to
10 Nm.
30.Fit injectors to fuel rail. Secure with clips.
31.Position fuel rail to inlet manifold. Engage
injectors, one bank at a time.
32.Position ignition coil bracket on inlet manifold
studs.
33.Secure ignition coil bracket and fuel rail to inlet
manifold with nuts. Tighten to
8 Nm.
34.Remove plugs from fuel feed and return pipes
and rail.
35.Connect hose and tighten clip.
36.Clean feed pipe union and connect fuel feed
pipe to fuel rail. Tighten union to
16 Nm.
37.Connect multiplugs to fuel injectors and fuel
temperature sensor.
38.Remove cloth from inlet manifold.
39.Apply a thin, uniform coating of Loctite 577
sealant to mating face of inlet manifold.
40.Fit ram housing to inlet manifold. Secure with
bolts. Tighten to
24 Nm.
41.Connect purge hose, crankcase breather hose,
servo and pressure regulator vacuum hoses to
ram housing.
42.Fit plenum chamber.
See Plenum Chamber
43.Reconnect battery negative lead.
44.Start engine. Check for leaks around fuel rail and
injectors.

19FUEL SYSTEM
12
REPAIR Refit
15.Ensure locations on fuel pressure regulator and
fuel rail are clean.
16.Fit new spacer ring and 'O' ring to fuel pressure
regulator. Lubricate 'O' ring with silicone grease.
17.Fit pressure regulator assembly to fuel rail.
18.Secure regulator connecting pipe in clip.
19.Secure with bolts. Tighten to
10 Nm.
20.Align ignition coil bracket to inlet manifold studs.
21.Secure ignition coil bracket and fuel rail to inlet
manifold with nuts. Tighten to
8 Nm.
22.Remove plugs.
23.Connect return pipe to regulator connecting pipe.
Secure with clip.
24.Connect vacuum hose to fuel pressure regulator.
25.Remove cloth.
26.Reconnect battery negative lead.
27.Start engine. Check for leaks around fuel
pressure regulator, fuel feed and fuel return
unions.IDLE AIR CONTROL (IAC)
Service repair no - 19.22.54
Remove
1.Disconnect battery negative lead.
2.Disconnect IAC multiplug.
3.Remove 2 bolts securing IAC to plenum.
4.Remove IAC.
5.Remove gasket and discard.
Refit
6.Ensure all mating faces are clean.
7.Using a new gasket, fit IAC to plenum. Secure
with bolts. Tighten to
2.3 Nm.
8.Connect multiplug.
9.Reconnect battery negative lead.

SFI
17
REPAIR ADD: 09/95 Refit
6.Fit a NEW filter to bracket.
NOTE: Ensure direction of flow arrow
stamped on canister is correct.
7.Position filter mounting bracket to chassis and
secure with nut and bolt.
8.Remove plugs from fuel hose ends.
9.Lubricate NEW 'O' rings with clean fuel and fit to
fuel hoses.
10.Connect fuel hoses to filter and tighten unions to
18 Nm.
CAUTION: Use two spanners when
loosening or tightening unions.
11.Remove stand(s) and lower vehicle.
12.Run the engine to check for any fuel leaks.FUEL PUMP AND GAUGE SENDER UNIT -
ADVANCED EVAPS
Service repair no - 19.45.03
A plastic fuel tank with a combined fuel pump and
gauge sender unit is fitted. The top flange of the pump
also houses a pressure sensor which is not removable
from the pump. The fuel pump is accessed through a
panel in the load space floor.
WARNING: Ensure that fuel handling
precautions given in 01 - Introduction are
strictly adhered to when carrying out
following instructions.
CAUTION: Before disconnecting any part
of fuel system, it is imperative that all dust,
dirt and debris is removed from around
components to prevent ingress of foreign matter
into fuel system.
Remove
1.Depressurise fuel system.
See fuel system -
depressurise - advanced evaps
2.Disconnect battery negative lead.
3.Check the amount of fuel in the tank. If the tank
is full, drain 2.4 US gallons (9 litres) minimum.
See fuel tank - draining - advanced evaps
4.Remove 6 screws securing tail door tread strip
and remove tread strip.
5.Remove RH luggage compartment side panel.
See CHASSIS AND BODY, Repair, rear
compartment lower trim panels

SFI
19
REPAIR ADD: 09/95
12.Using service tool LRT-19-009 loosen and
remove the metal locking ring.
13.Prise the pump from the tank opening using a
blunt instrument under the edge of the pump
flange. Once clear of the seal, tip the pump to
the right to allow fuel contained in the body of
the pump to drain into the tank.
CAUTION: Do not lift the pump from the
tank using the feed and return stubs.
14.Remove and discard seal.Refit
15.Fit NEW pump seal to tank opening.
16.Carefully lower pump into tank opening, pressing
firmly on the pump top flange to allow correct
positioning.
NOTE: Ensure location tag on pump top
flange is engaged correctly to tank
opening lip.
17.Fit locking ring and tighten to
35 Nmusing
service tool LRT-19-009.
18.Connect both fuel lines to the pump by pushing
the connectors down each line square to the
pump connection until the connectors positively
latch.
19.Connect vent hose to pressure sensor body.
20.Connect multiplugs to fuel pump and pressure
sensor.
21.Reconnect battery negative lead.
22.Refill tank with drained fuel.
23.Run the engine to check for any fuel leaks.
24.Fit access panel and secure with screws.
25.Reposition loadspace sound insulation and
carpet.
26.Fit RH luggage compartment side panel.
See
CHASSIS AND BODY, Repair, rear
compartment lower trim panels
27.Fit tail door tread strip and secure with screws.

19FUEL SYSTEM
24
REPAIRADD: 09/95 Refit
29.Fit NEW pump seal to tank opening.
30.Carefully lower pump into tank opening, pressing
firmly on the pump top flange to allow correct
positioning.
NOTE: Ensure location tag on pump top
flange is engaged correctly to tank
opening lip.
31.Fit locking ring and tighten to
35 Nmusing
service tool LRT-19-009.
32.Fit vent hose to fuel tank clips and connect to
pressure sensor.
33.With assistance, fit fuel tank into position.
34.Fit fuel tank cradle and secure with nuts and
bolts.
35.Align upper fuel tank strap and secure with nut
and bolt.
36.Fit NEW clip to fuel filler neck hose.
37.Connect fuel filler neck internal breather to tank.
38.Connect fuel filler neck hose to tank.
39.Position fuel filler neck hose clip and tighten until
head shears.
40.Connect vent line quickfit connector to
liquid/vapour separator.
41.Connect vent line hose connection.
42.Position anti-roll [sway] bar straps and secure
with nuts and bolts.
43.Remove stand(s) and lower vehicle.
44.Connect both fuel lines to the pump by pushing
the connectors down each line square to the
pump connection until the connectors positively
latches.
45.Connect multiplugs to fuel pump and pressure
sensor.
46.Reconnect battery negative lead.
47.Refill tank with drained fuel.
48.Run the engine to check for any fuel leaks.
49.Fit access panel and secure with screws.
50.Reposition loadspace sound insulation and
carpet.
51.Fit RH luggage compartment side panel.
See
CHASSIS AND BODY, Repair, rear
compartment trim panels
52.Fit tail door tread strip and secure with screws.FUEL TANK - DRAINING - ADVANCED EVAPS
Service repair no - 19.55.02
WARNING: Before removing the fuel tank
it must be drained.
WARNING: Petrol/gasoline vapour is
highly flammable and in confined spaces
is also explosive and toxic. Always have a
fire extinguisher containing FOAM, CO2, GAS or
POWDER close at hand when handling or draining
fuel. See Introduction
CAUTION: Before disconnecting any part
of fuel system, it is imperative that all dust,
dirt and debris is removed from around
components to prevent ingress of foreign matter
into fuel system.
NOTE: Assuming the fuel tank is FULL
drain the following quantities:
Renew Fuel pump = 9 Litres (2.4 US Gallons)
Renew Fuel filler neck = 22 Litres (6 US Gallons)
Renew Fuel tank = COMPLETE DRAIN
1.Depressurise fuel system.
See fuel system -
depressurise - advanced evaps
2.Disconnect battery negative lead.
3.Remove 6 screws securing tail door tread strip
and remove tread strip.
4.Remove RH luggage compartment side panel.
See CHASSIS AND BODY, Repair,

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.