sensor LAND ROVER DEFENDER 1996 Workshop Manual

01INTRODUCTION
10
INFORMATION CROSS REFERENCE OF EMISSION SYSTEM
TERMINOLOGY
NEW TERM (ACRONYM)
Accelerator pedal (AP).................................................
Air cleaner (ACL)..........................................................
Air conditioning (AC)....................................................
Battery positive voltage (B+)........................................
Closed loop (CL)..........................................................
Closed throttle position (CTP)......................................
Canister purge valve (CANPV)....................................
Data link connector (DLC)...........................................
Diagnostic trouble code (DTC).....................................
Distributor ignition (DI).................................................
Engine control module (ECM)......................................
Engine coolant level (ECL)...........................................
Engine coolant temperature (ECT)..............................
Engine coolant temperature sensor (ECTS)................
Engine speed (RPM)....................................................
Evaporative emission system (EVAP)..........................
Engine fuel temperature sensor (EFTS)......................
4th gear, 3rd gear etc. (4GR, 3GR)..............................
Fuel pump (FP)............................................................
Fan control module (FCM)...........................................
Generator (GEN)..........................................................
Ground (GND)..............................................................
Heated oxygen sensor (H02S)....................................
Idle air control (IAC)......................................................
Idle air control valve (IACV).........................................
Ignition control module (ICM).......................................
Intake air temperature (IAT).........................................
Manifold vacuum zone (MVZ)......................................
Mass air flow sensor (MAFS).......................................
Open loop (OL)............................................................
Relay module (RM)......................................................
Solid state relay module (SSRM).................................
Three way catalytic converter (TWC)..........................
Throttle body (TB)........................................................
Throttle position sensor (TPS)......................................
Transmission range (TR)..............................................
Wide open throttle (WOT)............................................OLD TERM (ACRONYM)
Throttle pedal (-)..........................................................
Air cleaner (-)...............................................................
Air conditioning (AC)....................................................
Battery plus, bat +, bat feed (B+).................................
Closed loop (-).............................................................
Closed throttle, idle position (-)....................................
Charcoal canister purge valve (-).................................
Serial link (-)................................................................
Fault code (-)...............................................................
Electronic ignition (-)....................................................
Electronic control unit (ECU)........................................
Coolant level (-)...........................................................
Coolant temperature (temp).........................................
Coolant temperature thermistor (-)..............................
Engine speed (rev/min)................................................
Evaporative loss system (ELC)...................................
Fuel temperature thermistor (-)....................................
Fourth gear, 3rd gear (-)..............................................
Fuel pump (-)...............................................................
Condenser fan timer (-)................................................
Alternator (-)................................................................
Ground, earth (B-)........................................................
Lambda (02) sensor (-)................................................
Idle speed control (ISC)................................................
Stepper motor (-).........................................................
Ignition module (-)........................................................
Intake temperature/ambient temperature (-)................
Manifold depression, vacuum (-).................................
Air flow meter (-)..........................................................
Fault code display unit (-)............................................
Open loop (-)...............................................................
Relay (-).......................................................................
Control unit (-)..............................................................
Catalyst, catalytic converter (CAT)..............................
Throttle housing (-)......................................................
Transmission gear (-)...................................................
Full throttle, wide open throttle (WOT).........................

ENGINE TUNING DATA
1
INFORMATION 300 Tdi ENGINE
Type2.5 Litre Turbo diesel intercooled .................................................................................
Firing order1-3-4-2 .....................................................................
Injection timing1,54 mm lift at T.D.C. ...............................................................
Injection timing with electronic EGR1,40 mm lift at T.D.C. ............................
Timing marks:
Valve timing - manual Slot for pin in flywheel and TDC mark on front pulley........................................................
Injection timing Timing pin (service tool).................................................................
Tappet clearances inlet and exhaust 0,20 mm cold...............................
Valve timing: Inlet Exhaust
- Opens 16°B.T.D.C. ............................................................................ 51°B.B.D.C.
- Closes 42°A.B.D.C. ............................................................................ 13°A.T.D.C.
- Peak 103°A.T.D.C. ............................................................................... 109°B.T.D.C.
- Lift 9,67 mm.................................................................................. 9,97 mm
Maximum governed speeds:
- No load (neutral/full throttle) 4600 + 40 - 120 rev/min...........................................
- Idle speed at running temperature 720±20 rev/min .................................
- Die-down time 4 seconds................................................................
INJECTION PUMP
Make & type - standard Bosch rotary R509 type with boost control and two....................................................
speed mechanical governor with auto advance and
solenoid electrical shut-off. Tamper proof sealing on,
no load governed speed and fuel adjustment screws.
Constant volume delivery valves
Make & type - Electronic EGR Bosch rotary R509/1 type with boost control and two.........................................
speed mechanical governor with auto advance and
solenoid electrical shut-off. Tamper proof sealing on
flight speed and fuel adjustment screws. Constant
volume delivery valves. Throttle position sensor for
EGR control.
HEATER PLUGS
Make & type Probe type, No.0100226129A Beru 12 volts.....................................................................
Time to reach operating temperature of 850°C 8 seconds...............

12ENGINE
20
REPAIR OIL FILTER HEAD GASKET
Service repair no - 12.60.03
Remove
1.Clean filter head adaptor.
2.Disconnect oil cooler pipes and plug to prevent
ingress of dirt.
3.Disconnect oil pressure switch lead.
4.Remove 4 bolts and withdraw filter head,
complete with gasket.
5.Clean mating faces of filter head and cylinder
block.
6.Fit head with new gasket.
7.Tighten bolts to
45 Nm (33 lbf/ft).
8.Reconnect oil pressure switch lead.
9.Reconnect oil cooler pipes.CYLINDER HEAD GASKET
Service repair no - 12.29.02
Remove
1.Disconnect battery
2.Remove bonnet.
3.Drain coolant.
See COOLING SYSTEM,
Repair, Drain and refill cooling system
4.Remove air cleaner.See FUEL SYSTEM,
Repair, Air cleaner
5.Detach crankcase ventilation valve and side
breather hose from rocker cover and move to
one side.
6.Remove fuel injectors and pipes.
See FUEL
SYSTEM, Repair, Fuel injectors
7.Remove heater plugs.See FUEL SYSTEM,
Repair, Heater plugs
8.Disconnect radiator top hose from thermostat.
9.Disconnect bleed hose at thermostat.
10.Disconnect water pump hose at thermostat.
11.Disconnect water temperature sensor lead.

ENGINE
23
REPAIR
43.Check and adjust valve clearances.
See Adjustment, Valve clearances - check
and adjust
44.Fit rocker cover, ensuring oil seal is satisfactory
for continued use, and renew if necessary.
45.Secure rocker cover with special seal washers
and nuts. Tighten to
10 Nm (7 lbf/ft).
46.Fit rear engine lifting bracket, securing breather
pipe and multi-plug retaining clips. Tighten fixing
bolts to
25 Nm (18 lbf/ft).
47.Fit engine harness bracket to cylinder head.
48.Secure air cleaner mounting bracket to support
strut.
49.Connect heater hose to rear of cylinder head.
50.Position heater rail and connect hose from water
pump.
51.Fit exhaust manifold and turbocharger assembly.
See MANIFOLD AND EXHAUST SYSTEM,
Repair, Exhaust manifold
52.Fit induction manifold.See MANIFOLD AND
EXHAUST SYSTEM, Repair, Induction
manifold
53.Connect water temperature sensor lead.
54.Connect water pump hose at thermostat.
55.Fit bleed hose at thermostat.
56.Connect radiator top hose at thermostat.
57.Fit heater plugs.
See FUEL SYSTEM, Repair,
Heater plugs
58.Fit fuel injectors.See FUEL SYSTEM, Repair,
Fuel injectors
59.Fit crankcase ventilation valve and side breather
hose.
60.Fit air cleaner.
See FUEL SYSTEM, Repair,
Air cleaner
61.Refill cooling system.See COOLING SYSTEM,
Repair, Drain and refill cooling system
62.Fit bonnet.
63.Reconnect battery.OIL PUMP
Service repair no - 12.60.26
Remove
1.Remove engine front cover.
See Front cover
gasket
2.Remove 7 screws and release oil pump retaining
plate from engine front cover.
3.Mark oil pump inner gear rotor, outer gear rotor
and front cover housing for reassembly.
4.Check for rotor clearances:
Outer rotor to housing, 0,025 - 0,075 mm (0.010
- 0.030 in).
Inner rotor to outer rotor, 0,025 - 0,075 mm
(0.010 - 0.030 in).
Rotor end float, 0,026 - 0,135 mm (0.010 - 0.054
in).
5.Remove inner and outer rotors.
6.Check condition of oil pump components.
NOTE: If the oil pump seating in the front
cover or retaining plate is badly worn,
pitted or scored, a new front cover must
be fitted.
See Front cover gasket
Always renew oil pump rotors as a pair.
7.Clean sealant from pump retaining plate and
front cover.

12ENGINE
2
SPECIFICATIONS, TORQUE REV: 05/99Nm
Cylinder head
Cylinder head to cylinder block
M10 x 117 40 Nm + 60° ..........................................................................................
M12 x 100 40 Nm + 60° ..........................................................................................
M12 x 140 40 Nm + 60°+20° ......................................................................................
Stub pipe heater feed 22.................................................................................
Water temperature sensor 14.........................................................................
Blanking plug cylinder head 14.......................................................................
Engine lifting brackets 25................................................................................
Electrical harness clip bracket 25...................................................................
Exhaust manifold stud 10................................................................................
Exhaust manifold nut 45.................................................................................
Inlet manifold stud 8.......................................................................................
Inlet manifold nut and bolt 25..........................................................................
Air temperature sensor, inlet manifold 14.......................................................
Blanking plug, inlet manifold 14......................................................................
Heatshield to inlet manifold 6.........................................................................
Glow plug 20...................................................................................................
Glow plug terminal nut 2................................................................................
Injector clamp (stud) 8...................................................................................
Injector clamp (nut) 25....................................................................................
Thermostat housing 25...................................................................................
Water outlet elbow to thermostat housing 25..................................................
Water temperature switch, thermostat housing 11..........................................
Plug thermostat housing 6.............................................................................
Rocker shaft pedestal bolt 5 Nm + 50° ..................................................................
Rocker cover (stud) 8.....................................................................................
Rocker cover (fixing nut) 10............................................................................
Breather cyclone to rocker cover 9................................................................
Tappet adjusting nut 16..................................................................................
Front cover to cylinder block 25......................................................................
Front cover plate to front cover 25..................................................................
Static idler - timing belt (stud) 10.....................................................................
Static idler - timing belt (nut) 45......................................................................
Tensioner (timing belt) 45...............................................................................
Camshaft hub bolt 80......................................................................................
Timing pulley to camshaft hub 25...................................................................
Fuel injection pump (stud) 8...........................................................................
Fuel injection pump (nut) 25...........................................................................
Abutment bracket to injection pump 25...........................................................
Support bracket injection pump to cylinder block 25.......................................
Fuel injection pump access plate to front cover plate 25................................
Timing pulley to injection pump hub 25...........................................................
TV Damper pulley bolt to crankshaft 80 Nm + 90° ..................................................
Fan pulley to hub 25.......................................................................................
Fan and viscous coupling to hub 45...............................................................
Auto tensioner, auxiliary drive (stud) 14..........................................................
Auto tensioner, auxiliary drive (nut) 45...........................................................
Auxiliary mounting bracket to cylinder block (stud) 8.....................................
Auxiliary mounting bracket to cylinder block (bolt and nut) 25........................
Water pump to block and mounting plate 25..................................................
Water pump pulley to hub 25..........................................................................

ENGINE
3
SPECIFICATIONS, TORQUENm
Turbo charger oil drain adaptor to block 42....................................................
Oil drain pipe to turbocharger 25....................................................................
Turbocharger oil drain pipe to adaptor 38.......................................................
Turbocharger oil feed pipe adaptor to block 25...............................................
Turbocharger oil feed pipe to adaptor 25........................................................
Oil feed pipe to turbocharger 19.....................................................................
Turbocharger to cylinder head (stud) 10.........................................................
Turbocharger to cylinder head (nut) 45...........................................................
Turbocharger to blanking plate 25..................................................................
Turbocharger to EGR valve 25.......................................................................
EGR delivery tube to valve 25........................................................................
EGR delivery tube to mixing tube 25..............................................................
Fuel lift pump to filter (union) 15.....................................................................
Fuel filter from lift pump (banjo bolt) 33...........................................................
Fuel filter to fuel injection pump (banjo bolt) 33..............................................
Fuel injection pump from fuel filter (banjo bolt) 25..........................................
Injector pipes to injectors and fuel injection pump 29.....................................
Spill rail to injectors (banjo bolt) 10.................................................................
Spill rail to injection pump (banjo bolt) 25.......................................................
Boost pipe injection pump (banjo bolt) 10.......................................................
Plug, rear of injection pump 29.......................................................................
PAS pump to mounting plate 25.....................................................................
PAS pump mounting plate to auxiliaries mounting bracket 25........................
PAS pump pulley to hub 25............................................................................
Starter motor (bolt and nut) 45........................................................................
Air conditioning compressor
Compressor mounting bracket to front cover 45.............................................
Compressor to mounting bracket (stud) 8......................................................
Compressor to mounting bracket (nut) 25......................................................
Belt tensioner pulley to tensioner arm 45........................................................
Belt tensioner assembly to front cover plate 25..............................................
Idler pulley to front cover plate 45...................................................................
Compressor belt guard (nut) 25......................................................................
Sensors to water outlet elbow (air/con) 25......................................................
Blanking plug, water outlet elbow (air/con) 25................................................
Generator
Generator mounting bracket to front cover 45................................................
Generator to mounting bracket 85..................................................................
Generator pulley to hub 95.............................................................................
Generator belt guard 25..................................................................................
Generator to auxiliaries mounting bracket 25.................................................
Tachometer electrical connection 4...............................................................

19FUEL SYSTEM
8
DESCRIPTION AND OPERATION
EGR FUEL SYSTEM COMPONENT LOCATION, (when fitted)
1.EGR modulator valve
2.Electrical harness plug
3.Vacuum spill pipe, modulator to air cleaner hose
4.Vacuum pipe, brake servo hose to modulator
valve
5.'T' piece connector
6.Vacuum pipe, vacuum pump to brake servo7.EGR valve
8.Vacuum pipe, modulator valve to EGR valve
9.Multi-plug connector, EGR valve
10.EGR control unit (fixed on base of centre seat or
cubby box)
11.EGR throttle position sensor

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
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