turbo LAND ROVER DEFENDER 1996 User Guide

19FUEL SYSTEM
2
DESCRIPTION AND OPERATION A mechanical lift pump, with a hand priming facility, is
driven by the camshaft, and is mounted on the RH
side of the engine.
A fuel filter, with a replaceable element and
incorporating a water separator, is mounted on the
front RH side of the engine compartment.
A fuel sedimentor may be fitted when the vehicle is
operating in more arduous conditions, and is used to
minimise water deposits in the fuel system before
reaching the fuel pump and filter.
Fuel injection is carried out by a Bosch direct injection
pump, incorporating a cold start advance unit and a
high idle setting. The pump is mounted on the RH side
of the engine and is driven directly by gears in the
front cover from the crankshaft. The pump meters and
distributes fuel to 4 pintle type injectors located in
pre-combustion chambers in the cylinder head. Four
heater plugs, located in the cylinder head directly
below each injector, are fitted to improve cold starting.
An optional hand throttle, for use with a centre power
take off, is located on the fascia to the LH side of the
fuse box, and is linked independently to the fuel
injection pump throttle lever.
Air intake
The air cleaner is mounted on the RH side of the
engine and is connected by hoses to the cold air
intake duct and turbocharger inlet. Fitted between the
air cleaner and turbocharger is the crankcase breather
hose which connects to a breather filter on the rocker
cover.
A single stage turbocharger, fitted between the
exhaust manifold and exhaust down pipe, is
connected by hoses to the air cleaner and an
intercooler which is mounted on the LH side of the
radiator. The intercooler is connected by a hose to the
inlet manifold. When an EGR valve is fitted to the
turbocharger, additional pipes/hoses are used to
connect the components.Exhaust gas recirculation (EGR), when fitted.
Exhaust gas recirculation is controlled by an ECU
mounted under the front centre seat or cubby box and
receives the following inputs:
·Engine temperature from coolant temperature
sender unit on LH side of cylinder head.
·Throttle position from potentiometer on injection
pump.
·Engine speed from speedometer.
When all correct signals are received, the EGR
solenoid allows vacuum to open EGR valve and
recirculate a portion of the exhaust gas. See J6196 for
the EGR system component location and 'Operation'
for full system function.

FUEL SYSTEM
7
DESCRIPTION AND OPERATION
FUEL SYSTEM COMPONENT LOCATION
1.Fuel filter bleed screw
2.Fuel filter
3.Turbocharger
4.Actuator
5.Air cleaner
6.Fuel injector7.Heater plug
8.Heater plug controller
9.Coolant temperature transmitter
10.Fuel injection pump
11.Fuel lift pump
12.Intercooler

FUEL SYSTEM
9
DESCRIPTION AND OPERATION OPERATION
Diesel engines operate by compression ignition. The
rapid compression of air in the cylinder during the
compression cycle heats the air and when fuel is
injected into the heated air, it ignites instantaneously.
During cold tarting, automatically controlled heater
plugs assist in raising the temperature of the
compressed air to ignition point.
A cold start advance unit advances the injection timing
to further assist starting. Idle quality is improved by
the high idle setting.
The engine is supplied with pre-compressed air by a
single stage turbocharger.
Exhaust gases passing over a turbine cause it to
rotate, driving a compressor mounted on the turbine
shaft. Air drawn from the cold air intake passes, via
the air cleaner, to the turbocharger where it is
compressed. Compression in the turbocharger warms
up the air considerably, so that it expands. As a result
the air mass per cylinder is reduced, having a
negative effect on power output. By fitting a charge-air
intercooler, located on the LH side of the radiator, the
air is cooled before reaching the cylinders. This
increases power output through increased mass of
oxygen in the combustion process, as well as
maximising engine durability, through maintaining
lower piston and head temperatures.
Fuel is drawn from the tank by a mechanical lift pump
and passes to the injection pump via a filter. In
addition to removing particle contamination from the
fuel, the filter incorporates a water separator, which
removes and stores water.
The sedimentor/s, when fitted, is located adjacent to
the fuel tank/s and separates contamination and water
particles in the fuel before reaching the fuel lift pump.
The injection pump meters a precisely timed, exact
quantity of fuel to the injectors in response to throttle
variations, injection timing varying with engine speed.
Any excess fuel delivered to the injection pump is
passed back to the tank via the spill return line.
Fuel is injected in a finely atomised form into the main
combustion chamber, the burning fuel expands
rapidly, creating extreme turbulence which mixes the
burning fuel thoroughly with the compressed air,
providing complete combustion.Cold Starting is assisted by heater plugs, a cold start
advance unit and a high idle setting.
Heater plugs
Heater plug operation is controlled by a timer unit,
start relay and resistor. When the ignition is turned on
the timer unit is energised, the heater plugs start to
operate and a warning light on the dashboard
illuminates, remaining on until the heater plugs are
automatically switched off.
The length of time the heater plugs will operate is
dependent on under bonnet temperature, which is
monitored by a sensor located in the timer unit.
Starting the engine results in the power supply to the
heater plugs passing through the resistor, which
reduces their operating temperature. The heater plugs
are cut out either by the temperature sensor in the
timer, or by a microswitch on the injection pump which
operates when the throttle is depressed.
Cold start advance
The cold start advance unit is connected to the engine
cooling system via hoses. It contains a temperature
sensitive element which is retracted when cold and
pulls the advance lever, via cable, towards the rear of
the pump against spring pressure. As coolant
temperature rises, the cold start element expands
releasing tension on the cable and allowing spring
pressure to move the advance lever forwards.
Exhaust gas recirculation (EGR), when fitted
Operation of the EGR system is dependent on the
following:
·Engine temperature - must be between 20°C and
100°C approx.
·Engine speed - must be between 630 and 2850
rev/min.
·Engine load - calculated by throttle position
sensor.
·EGR valve lift position.
·Duration of engine idling.

19FUEL SYSTEM
4
ADJUSTMENT TURBOCHARGER BOOST PRESSURE - CHECK
Service repair no - 19.42.06
1.Disconnect actuator hose from turbocharger and
insert a suitable 'T' piece connector.
2.Connect a short length of suitable hose to
turbocharger and 'T'piece.
3.Connect further hose to 'T' piece and pressure
gaugeLRT-12-011. The pressure gauge hose
must be long enough to reach into the vehicle
cab so that the gauge can be observed by driver
or passenger.
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. Under these circumstances
boost pressure should read 0,95 - 1,09 Kgf/cm
2
(13.5 - 15.5 lb/in2).PRIMING THE FUEL SYSTEM
Service repair no - 19.50.01
NOTE: If the fuel system has been
completely drained carry out the
procedures for priming both the
sedimentor, if fitted, and fuel filter and injection
pump.
Sedimentor and fuel filter
If the sedimentor or fuel filter have been dismantled
and air has entered the fuel system carry out the
following procedure:
1.Slacken fuel filter bleed screw.
2.Operate hand priming lever on fuel lift pump until
fuel, free from air, emerges from filter.
NOTE: Ensure that the fuel pump lever is
on the bottom of operating cam when
priming, otherwise maximum movement of
the lever cannot be achieved.
3.Tighten filter bleed screw whilst fuel is still
emerging.

19FUEL SYSTEM
14
REPAIR TURBOCHARGER INLET HOSE
Service repair no - 19.42.11
Remove
1.Disconnect battery.
2.Slacken retaining clip and disconnect intake
hose from turbocharger.
3.Slacken retaining clip and disconnect hose from
air cleaner.
4.If fitted, disconnect EGR modulator valve
vacuum spill pipe from inlet hose.
5.Slacken retaining clip and disconnect breather
valve hose from inlet hose.
6.Remove inlet hose.
Refit
7.Fit inlet hose to air cleaner.
8.Fit cyclone breather hose to inlet hose.
9.If applicable, fit vacuum spill pipe to inlet hose.
10.Fit inlet hose to turbocharger.
11.Reconnect battery.TURBOCHARGER OIL FEED PIPE
Service repair no - 19.42.14
Remove
1.Disconnect battery.
2.Remove exhaust front pipe.
See MANIFOLD
AND EXHAUST SYSTEM, Repair, Exhaust
front pipe
3.Remove banjo bolt securing oil feed pipe to
turbocharger and discard 2 joint sealing
washers.
4.Unscrew union and remove feed pipe from
cylinder block.
5.Plug connections to prevent ingress of dirt.
Refit
6.Using new joint washer, fit oil feed pipe to
cylinder block. Tighten union connector to
25
Nm (18 lbf/ft).
7.Fit a new joint washer to both sides of banjo and
secure feed pipe to turbocharger. Tighten banjo
bolt to
20 Nm (15 lbf/ft).
8.Fit exhaust front pipe.See MANIFOLD AND
EXHAUST SYSTEM, Repair, Exhaust front
pipe
9.Check/top-up engine oil level.See SECTION
10, Maintenance, Under bonnet maintenance
10.Reconnect battery.

FUEL SYSTEM
15
REPAIR TURBOCHARGER OIL DRAIN PIPE
Service repair no - 19.42.12
Remove
1.Disconnect battery.
2.Remove exhaust front pipe.
See MANIFOLD
AND EXHAUST SYSTEM, Repair, Exhaust
front pipe
3.Unscrew union and disconnect oil drain pipe
from cylinder block.
4.Remove 2 bolts securing oil drain pipe to
turbocharger.
5.Remove drain pipe and discard gasket.
6.Plug connections to prevent ingress of dirt.
Refit
7.Ensure mating surfaces of oil pipe, turbocharger
and engine block are clean.
8.Using new gasket, fit oil drain pipe to
turbocharger. Tighten bolts to
25 Nm (18 lbf/ft).
9.Fit drain pipe to cylinder block and tighten union
connector to
38 Nm (28 lbf/ft).
10.Fit exhaust front pipe.See MANIFOLD AND
EXHAUST SYSTEM, Repair, Exhaust front
pipe
11.Check/top-up engine oil level.See SECTION
10, Maintenance, Under bonnet maintenance
12.Reconnect battery.

COOLING SYSTEM
1
DESCRIPTION AND OPERATION ENGINE COOLING SYSTEM
Description
The complete cooling system of the 300Tdi engine
incorporates three independent functions:- Engine
(coolant) cooling; Turbo (charge air) intercooling;
Engine oil cooling.The intercooler is a separate aluminium unit, located
on the LH side of the engine compartment adjacent to
the radiator, sharing the same upper and lower
mountings. For details of turbo intercooling
See
FUEL SYSTEM, Description and operation,
Operation
. The oil cooler matrix is an integral part of
the radiator. Pre-formed pipes/hoses are used to link
the components within the separate systems as
shown below.
Engine cooling system
1.Radiator
2.Thermostat housing
3.Radiator bottom hose
4.Viscous fan
5.Water pump
6.Radiator top hose
7.Heater return hose
8.Coolant supply hose
9.By-pass hose
10.Radiator bleed (purge) hose
11.Bleed (purge) hose, thermostat housing
12.'Y' piece ejector
13.Expansion tank14.Heater rail
15.Heater unit
16.Heater feed hose
17.Intercooler
18.Air cleaner
19.Air feed hose
20.Turbocharger
21.Charge air supply pipe/hose
22.Cooled charge air supply hose
23.Exhaust manifold
24.Engine oil cooler
25.Feed pipe, engine oil cooler
26.Return pipe, engine oil cooler
27.Oil filter

MANIFOLD AND EXHAUST SYSTEM
1
REPAIR INDUCTION MANIFOLD
Service repair no - 30.15.02
Remove
1.Disconnect battery.
2.Remove oil filler cap and remove rocker cover
insulation.
3.Remove hose intercooler to induction manifold. If
fitted, remove EGR valve.
See FUEL SYSTEM,
Repair, EGR valve
4.Remove 2 screws and release heat shield from
induction manifold.
5.Slacken induction manifold lower securing nuts,
located below exhaust manifold.
6.Remove induction manifold upper securing bolts.
7.Remove induction manifold. Plug apertures in
cylinder head with clean rag to prevent any items
falling into engine.
8.Check gasket is satisfactory for further use.
Refit
9.Clean induction manifold mating face.
10.Position induction manifold and secure with
upper and lower fixings.
11.Tighten securing nuts and bolts to
25 Nm (18
lbf/ft).
12.Fit manifold heat shield.
13.Fit hose intercooler to induction manifold.
14.Fit rocker cover insulation.
15.Reconnect battery.INDUCTION/EXHAUST MANIFOLD GASKET
Service repair no - 30.15.15
Remove
1.Remove induction manifold
See Induction
manifold
.
2.Remove turbocharger outlet hose.
3.Raise vehicle and slacken exhaust front pipe to
intermediate silencer flange nuts. Ensure pipe is
free to turn.
NOTE: If removing exhaust manifold and
turbocharger assembly from vehicle,
remove manifold to exhaust front pipe
nuts while working under vehicle.
4.Remove exhaust manifold securing nuts,
removing centre lower nut first.
5.Move heater rail clear of exhaust manifold.
6.With exhaust manifold and turbocharger still
attached to exhaust front pipe, withdraw from
head by turning front pipe until sufficient access
is gained to remove gasket.
7.Suitably support exhaust manifold and
turbocharger assembly to prevent damage.
8.Remove induction manifold lower nuts.
9.Remove gasket.
10.Clean mating faces.

30MANIFOLD AND EXHAUST SYSTEM
2
REPAIR Refit
11.Fit new gasket over manifold studs.
12.Loosely fit induction manifold lower nuts to
studs.
13.Fit exhaust manifold and secure with central
upper and lower nuts.
14.Locate heater rail to its correct position and
secure with outer exhaust manifold nuts.
15.Tighten all exhaust manifold nuts to
45 Nm (33
lbf/ft).
16.Tighten exhaust front pipe to intermediate
silencer nuts to
50 Nm (37 lbf/ft).
17.Fit turbocharger outlet pipe.
18.Fit induction manifold
See Induction manifold
.EXHAUST MANIFOLD/TURBOCHARGER
ASSEMBLY
Service repair no - 30.15.10
Remove
1.Remove induction manifold
See Induction
manifold
.
2.Disconnect turbocharger inlet hose.
3.Disconnect boost pressure pipe at turbocharger.
4.Remove intercooler bottom hose.
5.Place suitable container under engine and
disconnect turbocharger oil feed and return
pipes at cylinder block.
6.Remove 3 nuts securing exhaust front pipe to
manifold flange.
7.Remove 7 nuts and lift exhaust manifold and
turbocharger assembly from cylinder head.
8.Discard manifold gasket.
Refit
9.Fit new manifold gasket.
10.Position exhaust manifold assembly onto
location studs and secure to cylinder head.
Tighten nuts to
45 Nm (33 lbf/ft).
11.Secure exhaust front pipe to manifold flange.
Tighten fixings to
50 Nm (37 lbf/ft).
12.Reconnect turbocharger oil feed and return
pipes at cylinder block.
13.Fit intercooler bottom hose.
14.Fit boost pressure pipe at turbocharger.
15.Fit turbocharger inlet hose.
16.Fit induction manifold
See Induction manifold
.

37MANUAL GEARBOX
2
REPAIR
10.Remove 3 trim studs and lift up handbrake
gaiter.
11.Remove split pin, clevis pin, washer and
disconnect cable from handbrake lever. Ensure
handbrake is off.
12.Drain cooling system
See COOLING SYSTEM,
Adjustment, Drain and refill cooling system
.
13.Remove viscous fan unit
See COOLING
SYSTEM, Repair, Viscous coupling and fan
.
14.Slacken retaining clip and disconnect radiator
top hose at thermostat housing.
15.Slacken retaining clip and disconnect intake
hose at induction manifold. If EGR system is
fitted, slacken 2 retaining clips and disconnect
intake hose at intercooler.
16.Slacken retaining clip and disconnect hose at
turbocharger.
17.Remove bolt securing transmission breather
pipe clip to rear of engine.
18.Release breather pipes.
19.Release ties securing gearbox harness to
breather pipes.
20.Raise vehicle on ramp.
21.Position a suitable container under transmission
and drain main gearbox and transfer box
See
MAINTENANCE , Under vehicle maintenance
.
22.Mark front propeller shaft drive flange and
transfer box output flange for reassembly.
23.Remove 4 nuts and disconnect propeller shaft
from transfer box.