Fuel system LAND ROVER DISCOVERY 2002 Workshop Manual

FUEL DELIVERY SYSTEM - TD5
19-1-10 DESCRIPTION AND OPERATION
Water sensor
The water sensor has a three pin electrical connector. When the sensor detects water in the filter it illuminates a
warning lamp in the instrument pack .

+ INSTRUMENTS, DESCRIPTION AND OPERATION, Description.
The water sensor attachment thread has a slot machined down one side. The filter can be purged of water by partially
unscrewing the sensor which aligns the slot in the threads with a corresponding hole in the sensor. When aligned,
water and fuel can flow down the slot and flows from a small cast tube on the side of the sensor. Re-tightening the
sensor misaligns the slot and stops the flow of fuel.
The water sensor receives a battery supply from the fuel pump relay in the engine compartment fusebox on one of
the electrical connector pins. The two remaining pins are connected to the instrument pack and an earth header joint.
The sensor operation uses the measurement of resistance between two electrodes submerged in the fuel and
activated by the presence of water.
When the ignition is moved to position II the warning lamp will illuminate for approximately two seconds to check
warning lamp functionality. TestBook can also illuminate the warning lamp to check its functionality.
When the filter is full with fuel and no water is present the resistance of the Diesel fuel will show a reading of 15 mA
maximum on the feed wire to the instrument pack. This current will not illuminate the water sensor warning lamp in
the instrument pack. When sufficient water surrounds both electrodes the resistance of the water will show a reading
of 130 mA maximum. This will supply sufficient voltage to the instrument pack to illuminate the warning lamp to alert
the driver to the presence of water in the fuel system.

FUEL DELIVERY SYSTEM - TD5
DESCRIPTION AND OPERATION 19-1-11
Operation
When the ignition switch is moved to position II, the fuel pump relay in the engine compartment fusebox is energised
by the ECM. Battery voltage is supplied from the fuel pump relay to the fuel pump which operates. If engine cranking
is not detected by the ECM within a three minute period, the ECM will 'time-out', de-energising the fuel pump relay.
When the ignition is turned off the ECM timer will reset.
The low pressure stage of the fuel pump draws fuel from the swirl pot and pumps it into the fuel filter. The high
pressure stage of the fuel pump draws the fuel from the fuel filter and pumps it along the fuel feed pipe to the cylinder
head.
The fuel enters the cylinder head through a connection on the fuel pressure regulator housing and supplies each
injector with pressurised fuel. The fuel pressure regulator maintains the fuel pressure at the injectors at 4 bar (58
lbf.in
2) by returning excess fuel back to the fuel filter. The returned fuel passes through the fuel cooler in the engine
compartment before it passes to the fuel filter.
When the engine is running, each injector is operated by an overhead camshaft which depresses a push rod in each
injector at a timed interval. When the cam has depressed the push rod and the push rod is returning to its extended
position, fuel is drawn from the fuel supply drilling into the injector.
When the ECM determines that injection is required, the ECM transmits an electrical pulse which energises the fast
acting solenoid, closing the spill valve on the injector and locking fuel in the injector body. As the cam begins to
depress the push rod, the fuel in the injector is rapidly pressurised. When the pressure exceeds the nozzle spring
pressure, the nozzle opens and injects fuel at very high pressure into the cylinder.
When the ECM determines that the injection period should end, the solenoid is rapidly de-energised, opening the spill
valve on the injector and allowing fuel to pass into the return circuit.
The ECM controls the injection timing by altering the time at which the solenoid is energised and the injection period
by controlling the period for which the solenoid is energised.

FUEL DELIVERY SYSTEM - TD5
19-1-12 DESCRIPTION AND OPERATION

FUEL DELIVERY SYSTEM - TD5
ADJUSTMENTS 19-1-13
ADJUST ME NTS
Fuel system purging
$% 19.50.07
If the vehicle runs out of fuel, or the fuel level is so
low that the fuel system draws air into the fuel rail,
the fuel rail will need to be purged before the engine
will start. This can be achieved by following the
procedure below.
If this procedure is carried out on a vehicle that
has not run out of fuel or otherwise drawn air into
the fuel rail, it can lead to the engine flooding and
failing to start.
Purge
1.Turn the ignition switch off and wait 15
seconds.
2.Turn the ignition switch to position II and wait 3
minutes (this ensures that the fuel system
purges all the air from the fuel rail within the
cylinder head).
3.Fully depress the throttle pedal.
4.Keeping the throttle pedal fully depressed,
crank the engine.
5.As soon as engine speed exceeds 600 rev/min,
release the throttle pedal and the ignition
switch.The engine must not be cranked
continuously for more than 30 seconds at
any one time.
6.If the engine fails to start, repeat the above
procedure.
Fuel tank - drain
$% 19.55.02
Drain
1.Disconnect both leads from battery.
WARNING: Always disconnect the negative
lead first. Disconnection of the positive lead
while the negative lead is connected could
result in a short circuit through accidental
grounding and cause personal injury.
2.Remove fuel pump.

+ FUEL DELIVERY SYSTEM - Td5,
REPAIRS, Pump - fuel.
3.Using a fuel recovery appliance, drain the fuel
from the tank into a sealed container. Follow
the manufacturers instructions for the
connection and safe use of the appliance.
Refill
1.Fit fuel pump.

+ FUEL DELIVERY SYSTEM - Td5,
REPAIRS, Pump - fuel.
2.Connect battery leads, positive terminal first.

FUEL DELIVERY SYSTEM - TD5
19-1-14 ADJUSTMENTS

FUEL DELIVERY SYSTEM - TD5
REPAIRS 19-1-15
REPAIRS
Switch - inertia - fuel cut-off
$% 19.22.09
Remove
1.Disconnect multiplug from fuel cut-off switch.
2.Remove 2 screws securing fuel cut-off switch to
bulkhead.
3.Remove fuel cut-off switch from bulkhead.
Refit
1.Position fuel cut-off switch to bulkhead and
secure with screws.
2.Connect multiplug to fuel cut-off switch.
3.To set the fuel cut-off switch, depress the top of
the fuel cut-off switch.
Pump - fuel
$% 19.45.08
NOTE: The fuel pump and fuel gauge tank unit are
integral parts of the fuel pump housing and cannot be
renewed separately
Remove
1.Release fixings and remove battery cover.
2.Disconnect battery earth lead.
3. Models with third row seats: Remove RH
third row seat.

+ SEATS, REPAIRS, Seat - third row.
4.Remove 5 trim clips securing lower edge of RH
'D' post trim casing.
5. Models with rear ICE controls: Remove
screw securing remote ICE controls to RH side
trim casing.
6. Models with rear ICE controls: Release ICE
controls from RH side trim casing. Disconnect
multiplug and remove ICE controls.
7.Partially remove tail door aperture seal in the
area of the RH side trim casing.

FUEL DELIVERY SYSTEM - TD5
19-1-16 REPAIRS
8.Remove 2 trim clips securing RH side trim
casing to body.
9.Remove rear lamp access panel from RH side
trim casing.
10.Remove trim clip securing RH side trim casing
to lower 'E' post.
11. Models with third row seats:Remove bolt
securing lower mounting of RH third row seat
belt to body.
12.Remove RH side trim casing.
13.Pull back loadspace carpet from fuel pump
access panel.
14.Remove 6 screws securing access panel.
15.Remove access panel.
16.Disconnect multiplug and 4 fuel hoses from fuel
pump housing.
CAUTION: Always fit plugs to open
connections to prevent contamination.17.Use LRT-19-009 to remove locking ring from
fuel pump housing.
18.Remove fuel pump housing.
19.Remove and discard sealing ring from fuel
pump housing.
Refit
1.Clean fuel pump housing and mating face on
fuel tank.
2.Fit new seal to mating face on fuel tank.
3.Fit fuel pump housing to fuel tank and use LRT-
19-009 to fit locking ring.
4.Connect multiplug and fuel hoses to fuel pump
housing. Ensure each hose is installed in the
connector with the corresponding colour
code.
5.Fit access panel and secure with screws.
6.Reposition loadspace carpet.
7.Fit RH side trim casing.
8. Models with third row seats:Fit bolt securing
lower mounting of RH third row seat belt to
body and tighten to 50 Nm (37 lbf.ft).
9.Fit trim clip securing RH side trim casing to
lower 'E' post.
10.Fit rear lamp access panel to RH side trim
casing.
11.Fit trim clips securing RH side trim casing to
body.
12.Fit tail door aperture seal.
13. Models with rear ICE controls: Connect
multiplug to remote ICE controls.
14. Models with rear ICE controls: Fit ICE
controls to trim casing and secure with screw.
15.Fit trim clips securing lower edge of 'D' post
trim casing to body.
16. Models with third row seats: Fit RH third row
seat.

+ SEATS, REPAIRS, Seat - third row.
17.Connect battery earth lead.

FUEL DELIVERY SYSTEM - TD5
REPAIRS 19-1-17
Tank - fuel
$% 19.55.01
Remove
1.Drain fuel tank.

+ FUEL DELIVERY SYSTEM - Td5,
ADJUSTMENTS, Fuel tank - drain.
2.Raise rear of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
3.Release clips securing filler and breather hoses
and release hoses from filler neck.
4.Disconnect fuel tank vent pipe from filler tube.
5.Support weight of fuel tank underneath cradle.
6.Remove 2 nuts and 2 bolts securing cradle to
chassis.
7.With assistance, lower LH side of fuel tank then
remove fuel tank from chassis.
8.Remove fuel tank from cradle.9.Remove 2 scrivets securing heat shield and
remove heat shield.
10.Release securing clip and remove breather
hose from fuel tank.
Refit
1.Fit breather hose to fuel tank and secure with
clip.
2.Position heat shield and secure with scrivets.
3.With assistance, position fuel tank and cradle.
4.Fit nuts and bolts securing cradle to chassis.
Tighten bolts to 50 Nm (37 lbf.ft) and nuts to 28
Nm (21 lbf.ft).
5.Connect fuel tank vent pipe to filler tube.
6.Connect breather and filler hoses and secure
with clips.

FUEL DELIVERY SYSTEM - TD5
19-1-18 REPAIRS
Solenoid - fuel filler flap release
$% 19.55.17
Remove
1.Remove loadspace RH side trim casing.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Trim casing - side - loadspace.
2.Remove 2 nuts and release solenoid from
body panel.
3.Disconnect multiplug and remove solenoid.
Refit
1.Position solenoid and connect multiplug.
2.Position solenoid to panel and tighten nuts.
3.Fit loadspace RH side trim casing.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Trim casing - side - loadspace.
Switch - fuel filler flap release - up to
03MY
$% 19.55.23
Remove
1.Carefully remove switch.
2.Disconnect multiplug from switch.
3.Remove switch.
Refit
1.Connect multiplug switch.
2.Position switch and push to secure.

FUEL DELIVERY SYSTEM - TD5
REPAIRS 19-1-19
Switch - fuel filler flap release - from
03MY
$% 19.55.23
Remove
1.Remove 2 screws securing instrument cowl to
fascia and release the cowl from the retaining
clips.
2.Disconnect multiplug from the fuel filler flap
release switch.
3.Remove the fuel filler flap release switch from
the instrument cowl.
Refit
1.Fit and secure the fuel filler flap release switch
to the instrument cowl and connect the
multiplug.
2.Fit the instrument cowl to the fascia and secure
with screws.