fuel filter LAND ROVER DEFENDER 1999 Owner's Manual

19FUEL SYSTEM
6
DESCRIPTION AND OPERATION The fuel pressure regulator is located in a machined port in the lower part of the housing. The regulator is sealed
in the housing with two’O’rings and secured with an internal clip.
The regulator maintains the fuel pump delivery pressure at 4 bar (58 lbf.in
2). When the fuel pressure exceeds 4
bar (58 lbf.in2), the regulator opens and allows fuel to return to the fuel tank via the fuel cooler. The fuel returned
from the regulator is directed back into the fuel filter before being drawn by the high pressure stage of the fuel
pump and directed back to the injectors. A special tool can be attached to the regulator housing fuel feed port and
allows for the fitment of a suitable gauge to measure fuel pump delivery pressure.
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FUEL SYSTEM
9
DESCRIPTION AND OPERATION FUEL FILTER
1.Filter body
2.Nut
3.Bolt
4.Rubber washer
5.Water sensor6.Filter element
7.Air bleed valve
8.Air bleed connection
9.Copper washer
10.Connector
The fuel filter is mounted on the chassis longitudinal below the rear RH wheel arch. The filter has four quick
release coupling connections; low pressure feed from the fuel pump, low pressure return to the fuel pump, return
line from the fuel pressure regulator and a bleed line to the fuel pump. The fuel filter removes particulate matter
from the fuel and also separates water which accumulates at the bottom of the filter.
An air bleed valve is located in the bleed line connection. The valve comprises a restrictor and a membrane. The
restrictor has a small hole in its centre. This allows air and fuel to pass through the membrane. Air can pass
through the membrane, but once the membrane is wet with fuel, it will not allow further fuel to pass through.
The fuel filter has a replaceable screw-on cannister type filter element which is sealed to the filter body with rubber
seals. The lower part of the cannister has a screw connection for a water sensor. The filter has a flow rate of 180
litres/hour (47.6 US Gallons/hour).
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19FUEL SYSTEM
10
DESCRIPTION AND OPERATION WATER SENSOR
The water sensor has a three pin electrical connector. When the sensor detects water in the fuel filter it illuminates
a warning lamp in the instrument pack.
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 mis-aligns the slot and stops the flow of fuel.
The sensor operates by measuring the resistance between its two electrodes, which are submerged in fuel, and
activated by the presence of water. When the ignition switch is moved to position’II’, the warning lamp will
illuminate for approximately 2 seconds to check warning lamp 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. 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, and alert the driver to the presence of water in the fuel system.
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FUEL SYSTEM
11
DESCRIPTION AND OPERATION OPERATION
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) 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 in 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.
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FUEL SYSTEM
1
REPAIR ELEMENT - AIR FILTER
Service repair no - 19.10.10
Remove
1.Release 2 clips and disconnect air flow meter
from air filter cover.
2.Disconnect multiplug from AAP sensor.
3.Release 2 clips and remove cover from air filter.
4.Remove air filter element.
Refit
5.Clean air filter body and cover.
6.Fit new air filter element.
7.Position air cleaner cover and secure clips.
8.Position air flow meter and secure clips.
9.Connect AAP sensor multiplug.SENSOR - FUEL TEMPERATURE
Service repair no - 19.22.08
Remove
1.Remove 3 bolts and remove engine acoustic
cover.
2.Release fixings and remove battery cover.
3.Disconnect battery negative lead.
4.Disconnect multiplug from fuel temperature
sensor.
5.Thoroughly clean area around fuel temperature
sensor before removal.
6.Remove fuel temperature sensor and discard
sealing washer.
Refit
7.Clean fuel temperature sensor mating faces.
8.Fit new sealing washer and tighten fuel
temperature sensor to13 Nm (9 lbf. ft).
9.Connect multiplug to fuel temperature sensor.
10.Reconnect battery negative lead.
11.Fit battery cover and secure fixings.
12.Fit engine acoustic cover and secure with bolts.
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19FUEL SYSTEM
4
REPAIR ELEMENT - FUEL FILTER
Service repair no - 19.25.07
Remove
1.Release fixings and remove battery cover.
2.Disconnect battery negative lead.
3.Raise rear of vehicle.
WARNING: Support on safety stands.
4.Release fixing and remove fuel filter cover.
5.Clean area around fuel filter.
6.Disconnect multiplug from filter element.
7.Remove fuel filter element.
Refit
8.Clean fuel filter and mating face.
9.Fit new fuel filter element and connect multiplug.
10.Position fuel filter cover and secure with fixing.
11.Remove stand(s) and lower vehicle.
12.Reconnect battery negative lead.
13.Fit and secure battery cover.COOLER - FUEL
Service repair no - 19.25.30
Remove
1.Remove 3 bolts and remove engine acoustic
cover.
2.Remove battery cover.
3.Disconnect battery negative lead.
4.Drain cooling system.See COOLING
SYSTEM, Adjustment.
5.Release 3 clips and disconnect 3 coolant hoses
from fuel cooler.
6.Release 2 fuel hoses from fuel cooler.
CAUTION: Plug the connections.
7.Release vacuum pipe clip from fuel cooler.
8.Remove 4 bolts securing fuel cooler to inlet
manifold and remove cooler.
Refit
9.Clean fuel hose connections.
10.Position fuel cooler to inlet manifold. Apply
Loctite 242 to bolts and tighten to18 Nm (13
lbf.ft).
11.Connect fuel hoses.
12.Connect coolant hoses, secure with clips.
13.Secure vacuum hose to fuel cooler.
14.Refill cooling system.See COOLING SYSTEM,
Adjustment.
15.Fit engine acoustic cover and secure with bolts.
16.Reconnect battery negative lead.
17.Fit battery cover.
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FUEL SYSTEM
5
REPAIR TURBOCHARGER
Service repair no - 19.42.01
Remove
1.Remove battery cover.
2.Disconnect battery negative lead.
3.Remove 3 bolts and remove engine acoustic
cover.
4.Release clip and disconnect breather hose from
camshaft cover.
5.Release clips and disconnect air flow meter from
air filter.
6.Disconnect multiplug from air flow meter.
7.Loosen clip screw and remove air inlet hose
from turbocharger.
8.Remove 3 bolts and remove exhaust manifold
heat shield.
9.Release clip and disconnect vacuum hose from
turbocharger wastegate.
10.Loosen clip screw and release air outlet hose
from turbocharger.
11.Remove turbocharger oil feed banjo bolt and
discard sealing washers.
12.Remove 3 nuts and release exhaust front pipe
from turbocharger and discard gasket.
13.Remove 3 nuts securing turbocharger to exhaust
manifold.
14.Loosen and unscrew turbocharger drain pipe
union from cylinder block.
15.Remove turbocharger and discard gasket.
16.Remove 2 bolts and remove turbocharger oil
drain pipe. Discard gasket.
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19FUEL SYSTEM
6
REPAIR Refit
17.Clean turbocharger and oil drain pipe mating
faces.
18.Using a NEW gasket, fit turbocharger drain pipe
and tighten bolts to10 Nm (7 lbf.ft).
19.Using a new gasket fit turbocharger to exhaust
manifold and tighten nuts to30 Nm (22 lbf. ft).
20.Position oil drain pipe to cylinder block and
tighten union.
21.Using new gasket, align exhaust front pipe and
tighten nuts to30 Nm (22 lbf.ft)
22.Fit banjo bolt to oil feed pipe using new sealing
washers and tighten to25 Nm (18 lbf.ft).
23.Position air outlet hose to turbocharger and
tighten clip screw.
24.Position and secure vacuum hose to
turbocharger wastegate.
25.Position exhaust manifold heat shield and
tighten M6 bolts to9 Nm (7 lbf.ft)and M8 bolt to
25 Nm (18 lbf.ft).
26.Position air inlet hose to turbocharger and
tighten clip screw.
27.Connect air flow meter to air filter and secure
clips.
28.Connect air flow meter multiplug.
29.Connect breather hose and secure clip.
30.Fit engine acoustic cover and secure with bolts.
31.Reconnect battery negative lead.
32.Fit battery cover.FILTER ASSEMBLY - AIR
Service repair no - 19.10.01
Remove
1.Loosen clip screw and release intake hose from
air filter.
2.Release 2 clips securing air flow meter.
3.Release air flow meter from air filter cover and
position aside.
4.Disconnect multiplug from AAP sensor.
5.Release air filter from 3 grommets, remove
assembly and discard’O’ring.
6.Remove 2 screws, remove AAP sensor and
discard’O’ring.
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FUEL SYSTEM
7
REPAIR Refit
7.Clean air flow meter faces.
8.Fit new’O’ring to air filter.
9.Clean AAP sensor.
10.Using new’O’ring, fit AAP sensor and tighten
screws.
11.Position air filter assembly and secure in
grommets.
12.Position air flow meter and secure clips.
13.Position intake hose to air filter and tighten clip
screw.INJECTOR - SET
Service repair no - 19.60.12
Remove
1.Remove cooling fan.See COOLING SYSTEM,
Repair.
2.Remove rocker shaft.See ENGINE , Repair.
3.Position container to catch fuel spillage.
4.Disconnect quick release fuel hose connectors
from fuel connector block on cylinder head and
fuel cooler to drain fuel from cylinder head.
5.Disconnect 5 multiplugs from injectors.
6.Remove Torx bolt securing injector unit to
cylinder head.
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FUEL SYSTEM
11
REPAIR REGULATOR - FUEL PRESSURE
Service repair no - 19.45.06
Remove
1.Remove battery cover.
2.Disconnect battery negative lead.
3.Remove 3 bolts and remove engine acoustic
cover.
4.Release hose from fuel cooler.
5.Release fuel hoses from pressure regulator.
CAUTION: Plug the connections.
6.Disconnect multiplug from fuel temperature
sensor.
7.Remove 3 bolts, remove pressure regulator from
cylinder head and collect gasket and’O’ring.
8.Remove fuel filter from cylinder head.
9.Remove fuel temperature sensor and discard
sealing washer.
10.Remove fuel hose and fuel pipe and discard’O’
rings.
Refit
11.Clean fuel pressure regulator, mating face and
fuel filter.
12.Clean fuel pipe unions.
13.Fit fuel pipe and fuel hose to pressure regulator
using new’O’rings.
14.Fit fuel temperature sensor using new sealing
washer and tighten to14 Nm (11 lbf.ft).
15.Fit fuel filter to cylinder head.
16.Using a new gasket and’O’ring position
pressure regulator and tighten bolts to25 Nm
(18 lbf.ft).
17.Connect fuel temperature sensor.
18.Connect fuel hoses to pressure regulator and
fuel cooler.
19.Fit engine acoustic cover.
20.Reconnect battery negative lead.
21.Fit battery cover.
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