1999 LAND ROVER DEFENDER lock

ENGINE MANAGEMENT SYSTEM
25
DESCRIPTION AND OPERATION Input / Output
The glow plugs receive a feed from the glow plug relay (C0215-3) on a yellow/black then individual black wires.
The ECM provides the earth path for the glow plug relay (C0151-6), working in tandem with the Alarm ECU. The
supply voltage heats the coils to approximately 1000°C (1832°F). The glow plug circuit is wired in parallel, the
body of each glow plug is screwed directly into the engine block which provides each glow plug with an earth path.
The glow plugs can fail in one or more of the following ways:
Heater coil open circuit.
Control coil open circuit.
Poor earth quality.
Short circuit to vehicle supply.
Short circuit to vehicle earth.
Harness fault.
Relay windings open circuit.
Incorrect relay fitted.
In the event of a glow plug failure, any of the following symptoms may be observed:
Difficult starting.
Excessive smoke emissions after engine start.
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ENGINE MANAGEMENT SYSTEM
27
DESCRIPTION AND OPERATION The turbocharger is exposed to extremely high operating temperatures (up to 1000°C, 1832°F) because of the
hot exhaust gases and the high speed revolution of the turbine (up to 15,000 rev/min). In order to resist wear of
the turbine bearings a flow of lubrication oil is supplied from the engine lubrication system to keep the bearings
cool. Oil is supplied from a tapping at the front of the full-flow filter adaptor housing via a metal pipe with banjo
connections. Oil is returned to the sump via a metal pipe which connects to the cylinder block at a port below the
turbocharger assembly.
A heatshield is attached to the LH side of the engine to protect adjacent components from the heat generated at
the turbocharger. The heatshield is attached to the engine by 2 bolts. An additional bolt attaches the heatshield to
the turbocharger casting.
The ECM controls the amount of boost pressure the engine receives by way of the turbocharger. When full boost
is reached a control signal is sent to the wastegate modulator, and a vacuum is applied to the wastegate valve.
The wastegate valve opens, bypassing some of the exhaust gases away from the turbine to be output to the
exhaust system.
The engine should be allowed to idle for 15 seconds following engine start up and before the engine is switched
off to protect the turbocharger by maintaining oil supply to the turbine bearings.
INTERCOOLER
The intercooler is an air-to-air heat exchanger which lowers the intake air temperature to obtain a higher air
density for better combustion efficiency. The intercooler receives compressed air from the turbocharger via a
metal pipe. It cools the intake air via the intercooler matrix and delivers it to the intake manifold by means of a
rubber hose which connects between the intercooler outlet and the intake manifold. The rubber hose is connected
to ports at each end by metal clips.
The intercooler is located at the front of the engine bay, forward of the radiator.
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19FUEL SYSTEM
2
DESCRIPTION AND OPERATION DESCRIPTION
General
The fuel delivery system comprises a fuel tank, fuel pump, fuel pressure regulator, five injectors and a fuel filter.
The system is controlled by the ECM, which energises the fuel pump relay and controls the operation and timing
of each injector solenoid.
Unlike other Diesel engines, the Td5 has no injection pump. The diesel direct injection system receives fuel at
pressure from a two stage fuel pump located in the fuel tank. The system incorporates a fuel return to the fuel
pump, via a fuel cooler attached to the inlet manifold, and a fuel filter. A fuel pressure regulator is located in a
housing on the rear of the cylinder head. The regulator maintains the fuel delivered to the injectors at a constant
pressure and returns excess fuel back to the fuel filter and pump via the fuel cooler.
A fuel filter is positioned on the chassis longitudinal, below the RH rear wheel arch. The fuel feed and return to and
from the engine passes through the filter. The filter also incorporates a water sensor, which illuminates a warning
lamp in the instrument pack.
A moulded fuel tank is located at the rear underside of the vehicle between the chassis longitudinals. The tank
provides the attachment for the fuel pump and the fuel gauge sender unit, which is located inside the tank.
Fuel Tank and Breather
The fuel tank and breather system is a major part of the fuel delivery system. The fuel tank and breathers are
located at the rear of the vehicle between the chassis longitudinals.
Fuel Tank
The moulded fuel tank is made from High Molecular Weight (HMW) High Density Polyethylene (HDPE), and is
manufactured using a proportion of recycled plastic.
The tank is held in position by a metal cradle which is secured to the chassis cross members by four bolts, two
holding the front of the cradle in position, two holding the rear. The fuel tank has a useable capacity of 75 litres
(16.5 gallons).
An aperture in the top surface of the tank allows for the fitment of the fuel pump and fuel gauge sender unit, which
is retained with a locking ring. A reflective metallic covering is attached to the tank with three scrivets to shield the
tank from heat generated by the exhaust system.
Fuel Tank Breather System
The fuel tank filler tube incorporates a tank vent which allows air and fuel vapour displaced from the tank when
filling to vent to atmosphere via the filler neck.
A breather spout within the tank controls the tank’Full’height. When fuel covers the spout it prevents fuel vapour
and air from escaping from the tank. This causes the fuel to’back-up’in the filler tube and shuts off the filler gun.
The position of the spout ensures that when the filler gun shuts off, a vapour space of approximately 10% of the
tanks total capacity remains. The vapour space ensures that the Roll Over Value (ROV) is always above the fuel
level and vapour can escape and allow the tank to breathe.
The ROV is welded to the top surface of the tank. It is connected by a tube to the filler tube, which in turn is
connected to the atmospheric vent pipe. The ROV allows fuel vapour to pass through it during normal vehicle
operation. In the event of the vehicle being overturned the valve shuts off, sealing the tank and preventing fuel
from spilling from the atmospheric vent pipe.
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FUEL SYSTEM
3
DESCRIPTION AND OPERATION FUEL PUMP AND FUEL GAUGE SENDER
1.Fuel burning heater feed pipe (not used)
2.Air bleed connection (natural)
3.HP feed connection (green)
4.LP feed connection (blue)
5.LP return connection (black)
6.Pump feed pipe.
7.Spring
8.Fuel gauge sender unit9.Swirl pot
10.Gauze filter
11.Fuel gauge sender float
12.Electrical connections
13.HP/LP two stage pump
14.Pump LP return pipe
15.Electrical connector
The fuel pump is a self priming, wet type, two stage pump, which is emersed in fuel in the tank. It operates at all
times when the ignition switch is in position’II’. If the engine is not started, the ECM will’time-out’after three
minutes and de-energise the fuel pump relay.
The fuel pump assembly is retained with a locking ring and sealed with a rubber seal. The locking ring requires a
special tool for removal and refitment. The fuel gauge sender is integral with the fuel pump. The sender is
submerged in the fuel and is operated by a float which moves with the fuel level in the tank.
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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
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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