fuel cap LAND ROVER DISCOVERY 1995 Owner's Manual

17EMISSION CONTROL
8
DESCRIPTION AND OPERATION ADD: 09/95 System operation
The system is designed to prevent fuel vapour
escaping to atmosphere, and consists of four roll-over
valves fitted internally in the fuel tank, connected to
the liquid/vapour separator by a nylon line. The
separator is mounted to the side of the filler neck. An
EVAP canister is positioned in the engine
compartment mounted on the right front side valance.
The liquid/vapour separator and EVAP canister are
connected by a nylon line which runs the length of the
chassis.
Pressure/vacuum relief valves are incorporated into
the fuel filler cap and are designed to protect the fuel
tank from permanent deformation in the event of
system pressure or vacuum exceeding the system
operating parameters. There are no other relief or
one-way valves in the system.
A vent line flow restrictor known as an anti-trickle fill
valve is fitted to the filler pipe in the line between the
tank and EVAP canister. The function of this valve is
to prevent overfilling the tank by trickling fuel in,
thereby preserving the vapour space in the tank to
allow for fuel expansion during hot weather.
The valve achieves this by blocking the vent line
during the fuel filling process. The valve is operated
by the action of inserting the filler gun so that when
the fuel in the tank reaches the level of the filling
breather, flow cut off occurs due to fuel filling the filler
pipe.During normal vehicle operation and when the engine
is switched off, the venting system between the fuel
tank and EVAP canister is open to allow the free
passage of vapour.
The EVAP canister, which is connected by a nylon
hose to the plenum chamber, absorbs and stores the
fuel vapour from the fuel tank when the engine is not
running. With the engine running, vapour is purged
from the EVAP canister by allowing outside air to be
drawn through the EVAP canister vent solenoid and
link pipe by the influence of manifold vacuum to the
EVAP canister purge connection on the canister.
Filter pads are fitted above and below the charcoal
and in the EVAP canister vent solenoid to prevent the
ingress of foreign matter into the purge line.
The EVAP canister purge valve, which is fitted in the
line from the EVAP canister to the plenum, is
controlled by the ECM which determines the most
emission acceptable time at which purging should
take place. This will normally be at engine speeds
above idle and when the vehicle is in motion.
The EVAP canister vent solenoid is mounted on the
side of the EVAP canister bracket and is connected to
the EVAP canister by a length of large bore hose. The
ECVS is controlled by the ECM and is normally open.
The function of the ECVS is to block the air intake
side of the EVAP canister. When the system receives
an ECM signal the valve closes; this allows the
system leak check to take place. The leak check only
occurs when pre-determined vehicle operating
conditions are met.

Tdi
1
DESCRIPTION AND OPERATION DESCRIPTION
Air intake
The air cleaner is positioned to the right of the engine
and connected by hoses to a cold air intake duct and
the turbocharger inlet. A crankcase breather hose is
fitted between the air cleaner and the separator.
A single stage turbocharger, fitted between the
exhaust manifold and exhaust pipe, is connected by
hoses to the air cleaner and to an intercooler mounted
on the right of the radiator. The intercooler is
connected by a hose to the inlet manifold.
Fuel system
A 89 litre fuel tank is mounted at the rear of the
vehicle beneath the load space floor. The tank is
vented by a 2 way valve in the filler cap.
A mechanical lift pump, driven by the camshaft, is
mounted on the side of the engine.
A fuel filter, fitted with a replaceable element and
incorporating a water separator, is positioned on the
LH side of the bulkhead.
A Bosch Type injection pump, incorporating a cold
start advance unit and a high idle setting is mounted
on the LH side of the engine and is directly driven by
gears from the crankshaft. The pump meters and
distributes fuel to 4 pintle type injectors located in
pre-combustion chambers in the cylinder heads.
A return line passes excess fuel from the injection
pump and injectors back to the fuel tank.
Glow plugs
Four glow plugs are located in the cylinder head,
directly below each injector.Exhaust gas recirculation (EGR)
Exhaust gas recirculation is controlled by the EGR
control unit mounted in the passenger compartment
on the RH 'A' post behind the fascia and receives the
following inputs:
a. Engine temperature from coolant temperature
transmitter in No. 4 cylinder head.
b. Throttle position from the sensor on the injection
pump.
c. Engine speed from the tachometer.
d. EGR valve lift position.
When all correct signals are received, the EGR
solenoid allows vacuum to open the EGR valve and
recirculate a portion of the exhaust gas.

19FUEL SYSTEM
2
ADJUSTMENT LOW AND HIGH IDLE SPEED
Adjust
The high idle speed (cold start idle) is
automatically set by the setting of the low idle
speed and can not be adjusted individually.
1.Check and adjust throttle cable.
2.Start engine and run it until normal operating
temperature is reached.
3.Using a suitable tachometer, check the engine
idle speed.
See ENGINE TUNING DATA,
Information, 300 Tdi Engine
4.If adjustment is necessary, loosen the locknut on
the injector pump.
5.Turn the adjustment screw either clockwise to
increase the engine speed or anti-clockwise to
decrease the speed. Run the engine at an
increased speed for a few seconds then check
the idle speed again.
6.When the correct speed has been achieved,
hold the adjuster screw steady while tightening
the locknut.
NOTE: The low idle speed control is the
only permitted adjustment in service. Any
additional adjustments required must be
entrusted to authorised Bosch agents.CHECK TURBOCHARGER BOOST PRESSURE
For boost pressure.
See ENGINE TUNING DATA,
Information, 300 Tdi Engine
1.Disconnect, from turbocharger, hose to actuator.
Insert into a suitable "T" piece.
2.Connect a short length of suitable hose to
turbocharger and connect other end to "T" piece.
3.Connect a further length of hose to third leg of
the "T" piece and other end to a pressure gauge
capable of reading in excess of 61 cm Hg. The
pressure gauge hose must be capable of
reaching passenger compartment so that gauge
may be observed.
4.To check maximum boost pressure, drive
vehicle normally but in such a manner that full
throttle can be maintained whilst climbing a hill
with engine speed held steady between 2,500
and 3,000 rev/min.

19FUEL SYSTEM
10
REPAIR EGR THROTTLE POSITION SENSOR
Service repair no - 19.30.14
Remove
1.Remove 2 screws securing sensor mounting
plate to injection pump.
2.Disconnect sensor multiplug from harness.
3.Remove sensor assembly.
Refit
4.Position sensor assembly on injection pump and
fit and tighten screws.
5.Connect multiplug.
6.Adjust sensor.
See Adjustment, EGR Throttle
Position Sensor
INJECTORS
Service repair no - 19.60.10
Remove
1.Remove oil filler cap and remove sound
deadening pad from top of engine.
2.Remove high pressure pipe from relevant
injector and injection pump.
3.Disconnect spill return hose(s) from injector.
4.Plug pipes and injector connections to prevent
the ingress of dirt and foreign matter.
5.Remove nut securing injector clamp plate to
cylinder head.
6.Remove injector.
Refit
7.Reverse removal procedure. Renew copper
washer on injector. Tighten injector clamp plate
nut to
25 Nm.

Tdi
11
REPAIR FUEL INJECTION PUMP AND TIMING
Service repair no - 19.30.07
NOTE: The following text refers to a Tdi
vehicle with a manual gearbox without
electronic diesel control. Where reference
is made to the timing tool substitute the following
information for automatic and EDC variants.
If manual gearbox:Timing tool LRT-12-044 fits into
the base of the flywheel housing
If manual gearbox with EDC:Timing tool
LRT-12-085 must be used and also fits into the base
of the flywheel housing.
If automatic gearbox:Timing tool LRT-12-044 fits
into the larger bolt hole of coverplate on engine
backplate, sited near to the rear of sump. Pin locates
in ring gear.
Remove
1.Disconnect battery negative lead.
2.Remove injection pipes, pump to injector.
3.Remove oil filler cap from rocker cover.
4.Viewing valve mechanism through filler aperture,
turn crankshaft clockwise until No. 1 cylinder is
just before TDC.
5.Refit oil filler cap.
6.Remove blanking plug from flywheel housing.
7.Fit timing tool LRT-12-044 to flywheel housing,
do not engage centre pin.
8.Continue rotating crankshaft clockwise until
centre pin engages with timing slot in flywheel.
9.Remove injection pump access plate, complete
with gasket, from front cover plate.
10.Fit pin from LRT-12-045 to injection pump gear.
11.Remove drive gear to pump hub fixing bolts and
plate.

19FUEL SYSTEM
14
REPAIR ENGINE CONTROL MODULE (ECM)
Service repair no - 18.30.03
NOTE: The ECM is not a serviceable item,
in the event of failure it must be renewed.
Remove
1.Disconnect battery negative lead.
2.Remove 'A' post trim pad.
3.Loosen multi-plug screw to ECM.
4.Disconnect multi-plug from ECM.
5.Secure multi-plug and harness aside.
6.Remove retaining nuts from ECM.
7.Manoeuvre ECM from its mounted position.
Refit
8.Refitting is the reverse of removal procedure.
9.Reconnect harness plug. Ensure plug is pushed
firmly into location and retaining clip secures
plug in position.
10.Tighten screw securing multi-plug.AIRFLOW METER
Service repair no - 18.30.15
NOTE: The air flow meter is not a
serviceable item, in the event of failure it
must be renewed.
Remove
1.Disconnect battery negative lead.
2.Release vacuum tube from EGR vacuum
capsule.
3.Disconnect airflow meter multi-plug.
4.Loosen air cleaner hose to air flow meter
retaining clip.
5.Disconnect hose from airflow meter.
6.Loosen turbo charger hose to airflow meter
retaining clip.
7.Disconnect hose from airflow meter.
8.Remove meter to mounting bracket bolts.
9.Remove airflow meter.
Refit
10.Reverse removal procedure. Ensure multi-plug is
firmly reconnected and hose clamps are
securely tightened to prevent unmetered air
entering the engine.

MFI
3
FAULT DIAGNOSIS FUEL PRESSURE CHECK
In order to check the fuel pressure it is necessary to
first depressurise the fuel system as follows:
WARNING: Under normal operating
conditions the multiport fuel injection
system is pressurised by a high pressure
fuel pump, operating at up to 2.3 to 2.5 bar. When
engine is stationary pressure is maintained within
system. To prevent pressurised fuel escaping and
to avoid personal injury it is necessary to
depressurise multiport fuel injection system
before any service operations are carried out.
If vehicle has not been run there will be a small
amount of residual pressure in fuel line. The
depressurising procedure must still be carried out
before disconnecting any component within the
fuel system.
The spilling of fuel is unavoidable during this
operation. Ensure that all necessary precautions
are taken to prevent fire and explosion.
A Pressure gauge 18G1500
B Fuel tank and pump
C Fuel filter
D Fuel injectors x 8
E Regulator1.Remove fuel pump relay module.
See Repair,
Multiport Fuel Injection Relay
2.Start and run engine.
3.When sufficient fuel has been used to cause fuel
line pressure to drop, injectors will become
inoperative, resulting in engine stall. Switch off
ignition.
4.Disconnect battery negative lead. .
NOTE: Fuel at low pressure will remain in
system. To remove low pressure fuel,
place absorbent cloth around fuel pipe at
the filter during disconnection.
5.Connect the pressure gauge on the outlet from
the filter, located on the chassis under the right
rear wheel arch.
6.Reconnect the battery and turn the ignition to
position II while observing the pressure gauge.
Results
Expected reading 2,39-2,672 kgf/cm
2
Pressure drop-max 0.7 kgf/cm2in one minute.
If pressure is low check that filter is not blocked
and pump is operating satisfactorily. Then
recheck pressure. If pressure is still low renew
regulator.
See Repair, Fuel Pressure
Regulator

19FUEL SYSTEM
6
REPAIR ENGINE COOLANT TEMPERATURE SENSOR
Service repair no - 19.22.18
Remove
1.Position drain tray to collect coolant spillage.
2.Disconnect multiplug from coolant sensor.
3.Remove sensor from thermostat housing.
4.Remove and discard copper washer.
Refit
5.Fit a new copper washer.
6.Fit sensor and tigten securely.
7.Top-up cooling system.
8.Run engine, check for water leaks around
sensor.DEPRESSURISING FUEL SYSTEM
WARNING: Under normal operating
conditions the Multiport fuel injection
system is pressurised by a high pressure
fuel pump, operating at up to 2.3 to 2.5 bar When
engine is stationary pressure is maintained within
system. To prevent pressurised fuel escaping and
to avoid personal injury it is necessary to
depressurise multiport fuel injection system
before any service operations are carried out.
If vehicle has not been run there will be a small
amount of residual pressure in fuel line. The
depressurising procedure must still be carried out
before disconnecting any component within the
fuel system.
The spilling of fuel is unavoidable during this
operation. Ensure that all necessary precautions
are taken to prevent fire and explosion.
1.Remove fuel pump relay module.
See
Multiport Fuel Injection Relays
2.Start and run engine.
3.When sufficient fuel has been used to cause fuel
line pressure to drop, injectors will become
inoperative, resulting in engine stall. Switch off
ignition.
4.Disconnect battery negative lead.
NOTE: Fuel at low pressure will remain in
system. To remove low pressure fuel,
place absorbent cloth around fuel feed
hose at fuel rail.
5.Disconnect either:
a) Nut and olive at fuel rail
OR
b) Hose at inlet end of fuel filter.
Refit
6.Refit fuel feed hose.
7.Refit fuel pump relay module, reconnect battery.
8.Crank engine (engine will fire in approximately 6
to 8 seconds).

SFI
11
DESCRIPTION AND OPERATION ADD: 09/95 Fuel Filler Neck Assembly
The filler neck consists of a stainless steel upper
section and a convolute nylon lower section. The
nylon lower is joined at one end to the tank and at the
other to the stainless upper section where both joints
utilise a short piece of rubber hose. The joint at the
fuel tank is secured using a spring assisted hose clip
which has a shear off cap.
NOTE: The spring assisted clip must never
be re-used, if removed a new clip of the
same type must be fitted.
Tank vent connections are achieved using serviceable
plastic quickfit connectors. The filler cap is tethered to
the body of the vehicle. Only a cap of this type must
be used as a replacement.Fuel Lines
The fuel lines consist of two coated steel lines fitted
along the length of the chassis from the fuel pump at
the rear of the vehicle to the connections at the fuel
rail on the engine, via a fuel filter on the feed line.
Connections at the pump are metal quickfits, while
those at the filter and fuel rail are threaded unions
utilising "O" rings for effective sealing.
NOTE: When the fuel filter is serviced or
the fuel rail joints are disconnected, new
"O" rings must always be fitted.
Connections at the fuel rail are made using "Saginaw"
screw thread type connectors with "O" rings as the
sealing medium. The fuel lines in the engine
compartment are made from a braided nylon material.
NOTE: This material must not be clamped
or kinked as this impairs its performance.

19FUEL SYSTEM
22
REPAIRADD: 09/95
12.Mark location of anti-roll [sway] bar straps.
13.Remove nuts and bolts securing anti-roll [sway]
bar straps, and allow bar to swing down clear of
tank.14.Disconnect pressure sensor breather pipe
connection.
15.Disconnect vent line quickfit connector from
liquid/vapour separator.
16.Remove torque screw cap from hose to tank
filler neck clip.
17.Loosen clip screw securing hose to tank filler
neck.
18.Release hose from filler neck and internal filler
neck breather hose from fuel tank.
19.Remove and discard fuel filler neck clip.