1996 LAND ROVER DEFENDER Workshop Manual

19FUEL SYSTEM
10
DESCRIPTION AND OPERATION Under varying engine speed and load condition the
control unit sends a signal to open the vacuum
modulator which allows a vacuum to be applied above
the EGR diaphragm. The vacuum supply is 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 sensor mounted on
the fuel injection pump throttle lever. Closed loop
control is achieved by allowing the control unit (ECU)
to continually monitor EGR valve lift via the sensor
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.

FUEL SYSTEM
1
ADJUSTMENT THROTTLE CABLE
Adjust
1.Slacken throttle cable adjustment ferrule.
2.Hold throttle lever in fully closed position.
3.Adjust outer cable, by rotating ferrule, to give
1,57 mm (1/16 in) of deflection 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 multi-plug.
3.Connect an Ohmmeter across pins 1 and 3 of
multi-plug. Ohmmeter should read between 1K
and 1.05K ohms.
4.Connect Ohmmeter across pins 1 and 2 of
multi-plug. Ohmmeter should read between 850
and 900 ohms.
5.If readings are correct, reconnect multi-plug.
6.If readings are not obtained slacken 2 torx
screws securing sensor.
7.Rotate sensor to obtain correct Ohmmeter
reading, then tighten torx screws.
8.Re-check readings and fit multiplug.
9.If, after adjustment, Ohmmeter readings cannot
be achieved, fit new sensor.
See Repair, EGR
throttle position sensor

19FUEL SYSTEM
2
ADJUSTMENT LOW AND HIGH IDLE SPEED ADJUSTMENT
NOTE: The high idle speed (cold start idle)
is automatically set by the setting of the
low idle speed and cannot be adjusted
individually.
1.Check and adjust throttle cable.
See 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, 300Tdi
4.If adjustment is necessary, first slacken the
locknut on injection pump.
5.Turn adjustment screw clockwise to increase
engine speed or anti-clockwise to decrease the
speed. Run engine at an increased speed for a
few seconds then check idle speed again.
6.When correct speed has been achieved, hold
adjuster screw steady while tightening 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.THROTTLE PEDAL ADJUSTMENT
Adjust
1.First ensure that throttle cable is correctly
adjusted
See Throttle cable
2.Depress throttle pedal, by hand, to full extent of
injection pump lever travel. Slacken locknut and
adjust throttle pedal stop screw to take up
clearance between screw and bulkhead. Ensure
no strain is placed upon throttle cable and pump
lever.
3.Retighten locknut.

FUEL SYSTEM
3
ADJUSTMENT INJECTION PUMP TIMING - CHECK AND ADJUST
Service repair no - 19.30.01
1.Viewing the valve mechanism through oil filler
aperture, turn crankshaft clockwise until inlet
valve of No.1 cylinder has just closed. No.1
cylinder is now just before TDC.
2.Remove blanking plug from flywheel housing
and insert timing toolLRT-12-044, locating
centre pin on flywheel.
NOTE: A chassis undertray may be fitted
on some vehicle derivatives to conform to
legal requirements. When under chassis
adjustments or remove and refit procedures are
required, it may be necessary to remove the
undertray and/or integral access panels.
See
CHASSIS AND BODY, Repair, Front undertray
or
See CHASSIS AND BODY, Repair, Rear undertray
3.Cearfully rotate crankshaft clockwise until centre
pin engages timing slot in flywheel.
4.Remove injection pump access plate, complete
with gasket, from front cover plate.
5.Fit locking pinLRT-12-045/2to injection pump
gear. If difficulty is experienced in inserting pin,
adjustments will be needed to correctly set
injection pump timing as follows:
6.Support injection pump retaining nut to prevent
strain on timing belt.
7.Slacken the 3 keeper plate retaining bolts.
8.Carefully turn fixing nut and keeper plate until
locking pin can be inserted, without restriction,
into injection pump gear.
9.Tighten keeper plate bolts to
25 Nm (18 lbf/ft)
and remove locking pin.
10.Refit injection pump access plate plate and
gasket.
11.Remove flywheel timing tool and refit blanking
plug.
12.Run engine until normal operating temperature is
reached and check that idle speed adjustment,
See low and high idle speed adjustmentand
throttle cable adjustment
See Throttle cable
are correct.

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.

FUEL SYSTEM
5
ADJUSTMENT Fuel injection pump
If the fuel injection pump has been removed or
renewed carry out the following:
1.Slacken fuel inlet pipe banjo bolt at injection
pump.
2.Operate hand priming lever on fuel lift pump until
fuel, free from air, emerges from injection pump.
3.Tighten banjo bolt whilst fuel is still emerging.
4.Crank engine until fuel is drawn through the
system and engine starts.
5.Check fuel connections for leaks.

FUEL SYSTEM
1
REPAIR FUEL INJECTION PUMP
Service repair no - 19.30.07
Remove
1.Disconnect battery.
2.Disconnect and remove high pressure fuel
injection pipes, pump to injectors.
3.Viewing valve mechanism through oil filler cap
aperture, turn crankshaft clockwise until No. 1
cylinder is just before TDC.
4.Remove blanking plug from flywheel housing
and fit timing toolLRT-12-044, locating centre
pin on flywheel.
NOTE: A chassis undertray may be fitted
on some vehicle derivatives to conform to
legal requirements. When under chassis
adjustments or remove and refit procedures are
required, it may be necessary to remove the
undertray and/or integral access panels
See
CHASSIS AND BODY, Repair, Front undertray
or
See CHASSIS AND BODY, Repair, Rear undertray
5.Carefully rotate crankshaft clockwise until centre
pin engages with timing slot in flywheel.
6.Remove injection pump access plate, complete
with gasket, from front cover plate.
7.Fit pin fromLRT-12-045to injection pump gear.
8.Restrain pulley nut to prevent straining timing
belt and remove drive gear to pump hub fixing
bolts and retaining plate.
9.Remove pin from pump gear.
10.Fit gear retaining toolLRT-12-045with an 8 mm
washer, 1,5 - 2 mm thick, under each bolt head
in addition to the existing washer.
11.Remove throttle cable and hand throttle cable, if
fitted.
12.Disconnect lead from fuel cut-off solenoid, and
EGR throttle position sensor multi-plug, if fitted.

19FUEL SYSTEM
2
REPAIR
13.Remove banjo bolts securing spill return, main
fuel and boost signal pipes, refit banjo bolts after
disconnecting pipes.
14.Remove 2 bolts securing rear of pump to
mounting bracket.
15.Remove 3 pump securing nuts at flange and
withdraw pump and gasket.
16.Fit suitable caps to pipe connections to prevent
ingress of dirt.
Refit
17.Clean mating faces of pump and front cover and
fit new gasket into position over pump mounting
studs.
18.Remove pump blanking plugs.
19.Slacken the 3 bolts, securing injection pump
mounting bracket to cylinder block, sufficiently
enough to allow bracket to move.
20.Fit pump to cover and secure with 3 nuts.
Tighten to
25 Nm (18 lbf/ft).
21.Loosely attach pump to mounting bracket with
nuts and bolts, then tighten bolts securing
bracket to cylinder block and bolts securing
pump to bracket, finger tight only.
22.To ensure correct fitting and alignment of
injection pump, first tighten the 2 bolts securing
pump to mounting bracket to
25 Nm (18 lbf/ft).
Then tighten the 3 bolts securing mounting
bracket to cylinder block, also to
25 Nm (18
lbf/ft).
23.Connect spill return and main fuel pipes and
secure with banjo bolts. Tighten to
25 Nm (18
lbf/ft).
24.Connect boost signal pipe and secure with banjo
bolt. Tighten to
10 Nm (7 lbf/ft).
25.Connect fuel cut-off solenoid lead and throttle
position sensor multi-plug, if fitted.
26.Connect throttle cable and where applicable,
hand throttle cable.
27.Remove pump gear retaining toolLRT-12-045.
28.Carefully turn the pump hub nut in a clockwise
direction, sufficiently enough to enable timing
tool pin to be inserted into injection pump.
29.Fit gear retaining plate and secure with 3 bolts.
Tighten to
25 Nm (18 lbf/ft).
30.Remove timing pin.
31.Ensure flywheel timing pin is disengaged from
slot in flywheel.
32.Turn crankshaft two complete revolutions, check
timing pin fromRT-12-045can be fully and
easily inserted into the pump. At the same time
check flywheel timing pinLRT-12-044can also
be inserted in the flywheel slot.
33.If, with the flywheel timing pin located, the timing
pin cannot be inserted cleanly into the injection
pump, carry out the following:
a.Ensure flywheel timing pin is disengaged from
slot in flywheel.
b.Slacken the 3 pump gear retaining bolts.
c.Turn the pump hub nut in a clockwise
direction, sufficiently to enable timing tool pin to
be easily inserted into the injection pump.
d.Keeping the tension on the hub nut, check
that flywheel timing pin locates with slot in
flywheel.
e.Tighten the 3 pump gear retaining bolts to
25
Nm (18 lbf/ft).
f.Remove timing pins from pump and flywheel
housing.
34.Using a suitable anti-seize compound, fit the
blanking plug to flywheel housing. Tighten to
12
Nm (9 lbf/ft).
35.Fit access plate with gasket to front cover plate.
Tighten bolts to
25 Nm (18 lbf/ft).
36.Refit injector pipes.
37.Reconnect battery.