Land Rover Range Rover Classic Workshop 1995 Rover Manual

							Tdi
3
DESCRIPTION AND OPERATION 
						

							19FUEL SYSTEM
4
DESCRIPTION AND OPERATION OPERATION
Diesel engines operate by compression ignition. The
rapid compression of air in the cylinder during the
compression cycle heats the injected fuel, causing it
to self ignite. During cold starting, automatically
controlled glow 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. The compressed air passes to the
cylinders via an intercooler, which reduces the
temperature of the compressed air, increasing its
density.
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 both bound and unbound water.
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 not
injected, passing back to the tank via the fuel return
line.
Fuel is injected in a finely atomised form into a
pre-combustion chamber in the cylinder head where it
ignites. The burning fuel expands rapidly into the main
combustion chamber, creating extreme turbulence
which mixes the burning fuel thoroughly with the
compressed air, providing complete combustion.
Cold Starting is assisted by glow plugs, a cold start
advance unit and a high idle setting.Glow plugs
Glow plug operation is controlled by a timer unit, start
relay and resistor. When the ignition is turned on the
timer unit is energised, the glow plugs start to operate
and a warning light on the dashboard illuminates,
remaining illuminated until the glow plugs are
automatically switched off.
The length of time the glow 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
glow plugs passing through the resistor, which
reduces their operating temperature. The glow 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. 
						

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5
DESCRIPTION AND OPERATION Exhaust Gas Recirculation (EGR)
Operation of the EGR system is dependent on the
following:
a. Engine temperature - must be between 20°C
and 100°C approx.
b. Engine speed - must be between 630 and 2850
rev/min.
c. Engine load - calculated by throttle
potentiometer position.
d. EGR valve lift position.
e. Duration of engine idling.
Under varying engine speed and load conditions the
control unit sends a signal to open the vacuum
modulator which allows a vacuum to be applied above
the EGR valve diaphragm, the vacuum supply being
taken from a T connector in the brake servo hose.
This process is controlled by an engine speed/load
map stored in the EGR control unit memory.
Engine speed is measured by monitoring the
waveform present on one phase of the generator.
Throttle position is measured via a potentiometer
mounted on the fuel injection pump throttle lever.
Closed loop control is achieved by allowing the control
unit to continually monitor EGR valve lift via a
potentiometer mounted on the valve; this valve lift is
compared with the actual valve lift required on the
control unit map and adjusted if necessary.
With coolant temperature between 20°C and 100°C;
the engine having just returned to idle, EGR will shut
off after 25-30 seconds idling. 
						

							Tdi
1
ADJUSTMENT THROTTLE CABLE
Adjust
1.Loosen throttle cable adjustment ferrule.
2.Hold throttle lever in fully closed position.
3.Adjust outer cable, by rotating ferrule, to give
1.57 mm (0.062 in) of free play in the inner
cable.
4.Check that throttle opens fully when the throttle
is depressed.EGR THROTTLE POSITION SENSOR
Check
1.Run engine until normal operating temperature is
reached.
2.Switch off engine and disconnect throttle position
sensor multiplug.
3.Connect an Ohmmeter across pins 1 and 3 of
multiplug. Ohmmeter should read between 1K
and 1.05K ohms.
4.Connect an Ohmmeter across pins 1 and 2 of
multiplug. Ohmmeter should read between 850
and 900 ohms.
5.If the readings are correct, EGR position sensor
is OK - reconnect multiplug.
6.Loosen 2 Torx screws securing position sensor.
7.Rotate position sensor to achieve correct
Ohmmeter readings, then tighten Torx screws.
8.Re-check Ohmmeter readings, then reconnect
multiplug. 
						

							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, Engine - 300Tdi
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, Turbocharger
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. 
						

							Tdi
1
REPAIR TANK SENDER UNIT
Service repair no - 88.25.32
WARNING: Ensure that the WARNINGS
and FUEL HANDLING PRECAUTIONS
given in Section 01 are adhered to before
carrying out the following operations.
Special tool - LST131
Remove
1.Disconnect battery negative lead.
2.Remove the rear carpet retainer.
3.Ease the carpet from under the lower trim panels
at the rear of the fold down seats.
4.Raise the carpet to expose the sound insulation.
5.Fold back the sound insulation to reveal the
access panel.
6.Remove the securing screws and detach the
access panel from the floor.
7.Disconnect the multi-plug from sender unit.8.Disconnect the fuel pipes from the sender unit.
9.Using special tool LST131 remove the locking
ring and withdraw the sender unit from the fuel
tank.
Refit
10.Fit the sender unit to the fuel tank and secure
with the locking ring. Tighten to
45to50 Nm.
11.Connect the fuel pipes to the sender unit.
12.Connect multi-plug to sender unit.
13.Inspect the access panel seal to ensure that it is
satisfactory for further use, renew as necessary.
14.Fit the access panel to the aperture in the floor
and secure with the screws.
15.Reverse removal procedure. 1 to 5. Refit the
sound insulation and carpet. 
						

							19FUEL SYSTEM
2
REPAIR THROTTLE CABLE
Service repair no - 19.20.06
Remove
1.Disconnect battery negative lead.
2.Remove pin and clevis pin securing throttle
cable to throttle lever.
3.Pull ferrule from abutment bracket and withdraw
throttle cable.
4.Release throttle cable from clip on bulkhead.
5.Remove pin and clevis pin securing throttle
cable to throttle lever.
6.Release grommet from bulkhead.
7.Withdraw throttle cable from engine
compartment.
Refit
8.Reverse removal procedure. Use new pins to
secure clevis pins.
9.Adjust throttle cable.
See Adjustment,
Throttle Cable Adjustment
INTAKE HOSE TURBOCHARGER
Service repair no - 19.42.11
Remove
1.Disconnect battery negative lead.
2.Loosen clip and disconnect intake hose from
turbocharger.
3.Loosen clip and disconnect breather hose from
intake hose.
4.Remove clip and disconnect hose from air
cleaner, discard clip.
5.Remove intake hose
Refit
6.Reverse removal procedure. Use a new clip to
secure intake hose to air cleaner. 
						

							Tdi
3
REPAIR TURBOCHARGER OIL FEED PIPE
Service repair no - 19.42.14
Remove
1.Disconnect battery negative lead.
2.Remove exhaust front pipe.
See MANIFOLD
AND EXHAUST SYSTEM, Repair, Manifold
and Exhaust System - Tdi
3.Remove banjo bolt securing oil feed pipe to
turbocharger, discard 2 sealing washers.
4.Unscrew union, disconnect oil feed pipe from
cylinder block.
CAUTION: Plug the connections.
5.Move oil feed pipe from behind turbocharger and
remove.
Refit
6.Reverse removal procedure. use new sealing
washers.
7.Tighten banjo bolt to
20 Nm.
8.Check/top-up engine oil level.TURBOCHARGER OIL DRAIN PIPE
Service repair no - 19.42.12
Remove
1.Disconnect battery negative lead.
2.Remove exhaust front pipe.
See MANIFOLD
AND EXHAUST SYSTEM, Repair, Manifold
and Exhaust System - Tdi
3.Unscrew union and disconnect oil drain pipe
from cylinder lock.
4.Remove 2 bolts securing oil drain pipe to
turbocharger.
5.Remove oil drain pipe, remove and discard
gasket.
CAUTION: Plug the connection.
Refit
6.Ensure mating surfaces of oil pipe, turbocharger
and engine block are clean.
7.Reverse removal procedure. Use a new gasket.
8.Tighten oil drain pipe to turbocharger bolts to
25
Nm.
9.Check/top-up engine oil level. 
						

							19FUEL SYSTEM
4
REPAIR TURBOCHARGER ACTUATOR
Service repair no - 19.42.31
Remove
1.Remove exhaust manifold and turbocharger.
See MANIFOLD AND EXHAUST SYSTEM,
Repair, Exhaust Manifold - Tdi
2.Remove 2 nuts securing the actuator to the
turbocharger bracket.
3.Release clip and disconnect hose from actuator.
4.Remove and discard clip securing control lever
to wastegate spindle.
5.Remove turbocharger actuator.
Refit
6.Fit the replacement actuator and secure with
nuts.
7.Push the control lever as far as possible towards
the actuator and apply pressure to keep the
lever in this position.
8.Pressurise the actuator to 57 - 62 cm Hg and
hold this pressure.
CAUTION: Use only the threaded end of
the lever to make adjustments. Forcing the
complete lever in or out will change the
calibration with the possibility of damaging engine
boost.
9.Screw the lever in either direction until the eye
on the end will locate easily over the wastegate
spindle and secure with a new clip.
10.Release the pressure and tighten the locknut.
11.Refit exhaust manifold and turbocharger.
See
MANIFOLD AND EXHAUST SYSTEM, Repair,
Exhaust Manifold - Tdi
TURBOCHARGER AND GASKET
Service repair no - Turbocharger - 19.42.01
Service repair no - Gasket - 19.42.25
Remove
1.Disconnect battery negative lead.
2.Remove air cleaner assembly.
See Air Cleaner
Assembly
3.Remove exhaust manifold assembly.See
MANIFOLD AND EXHAUST SYSTEM, Repair,
Exhaust Manifold - Tdi
4.Remove and discard clip securing control lever
to wastegate spindle.
5.Remove 4 bolts and 2 clamp plates securing
turbocharger to exhaust manifold.
6.Remove turbocharger and discard gaskets.
Refit
7.Clean mating faces of turbocharger and exhaust
manifold.
8.Reverse removal procedure. Use new clip to
secure control lever to wastegate spindle.
Tighten to
45 Nm.
9.Check/top-up engine oil level. 
						

							Tdi
5
REPAIR FUEL LIFT PUMP
Service repair no - 19.45.09
Remove
1.Loosen unions securing fuel injection pipes to
injectors and injector pump. Remove injection
pipes.
2.Plug the connections to prevent the ingress of
foreign material.
3.Loosen unions and disconnect fuel supply and
feed hoses from fuel lift pump.
4.Plug the connections to prevent the ingress of
foreign material.
5.Remove 2 bolts securing lift pump to engine
block.
6.Remove fuel lift pump and discard gasket.Refit
7.Clean mating faces of fuel lift pump and engine
block.
8.Using a new gasket, fit fuel pump, ensure correct
location of lever with camshaft. Fit securing
bolts. Tighten to
25 Nm.
9.Connect fuel hoses to pump and secure unions.
Tighten to
33 Nm.
10.Fit injector pipes to injectors and injection pump,
and secure unions. Tighten to
28 Nm.