coolant temperature LAND ROVER DISCOVERY 1995 User Guide

12ENGINE
8
REPAIR 21.Release clip and disconnect inlet hose from
power steering pump.
22.Disconnect outlet pipe union at power steering
pump, discard 'O' ring.
CAUTION: Plug the connections
23.Release throttle cable from abutment bracket.
24.Release throttle cable from cam. Also remove
coolant bypass hose from throttle housing.
25.Disconnect stepper motor and throttle
potentiometer multiplugs.
26.Release clip and disconnect hose, air cleaner to
throttle housing.
27.Release clip and disconnect brake servo hose
from manifold.
28.Disconnect fuel temperature sensor multiplug.

Mpi
13
REPAIR 19.Connect crankshaft sensor, knock sensor, air
conditioning compressor, fuel injector harness,
inlet manifold air temperature and fuel
temperature sensor multiplugs.
20.Connect fuel hose to pressure regulator and
secure with clip.
21.Fit and tighten fuel pipe to fuel rail union.
22.Connect multiplugs to throttle housing.
23.Connect vacuum hose to manifold.
24.Connect oil pressure switch multiplug.
25.Connect brake servo hose to manifold, secure
with clip.
26.Connect throttle cable to cam.
27.Position engine harness and connect breather
hose to inlet manifold, secure with clip.
28.Connect coolant temperature sensor multiplugs,
secure harness with cable tie.
29.Connect oxygen sensor multiplug, secure
harness with cable tie.
30.Connect alternator harness.
31.Connect heater hose to heater rail and secure
with clip.
32.Connect hose to coolant pump and secure with
clip.
33.Connect inlet hose to power steering pump and
secure with clip.
34.Fit and tighten outlet pipe union to power
steering pump.
35.Connect bypass and top hose, secure with clip.
36.Connect air cleaner to throttle housing hose and
secure with clip.
37.Remove engine lifting bracket.
38.Position spark plug cover and secure with
screws.
39.Fill engine with oil.
40.Fit bonnet [hood].
See CHASSIS AND BODY,
Repair, Bonnet [Hood]
41.Fit radiator.See COOLING SYSTEM, Repair,
Radiator - Mpi
42.Adjust throttle cable.See FUEL SYSTEM,
Adjustment, Throttle Cable Adjustment
ENGINE SUMP GASKET
Service repair no - 12.60.43
Remove
1.Drain engine oil.
2.Refit drain plug, use new sealing washer if
necessary, tighten to the correct torque.
3.Remove 18 bolts securing sump.
NOTE: 25mm long bolt is fitted at rear L.H.
corner of sump.
4.Release sump from cylinder block.
5.Discard gasket.

Mpi
15
REPAIR 4.Release clip and disconnect hose from heater
rail.
5.Disconnect 2 coolant temperature sensor
multiplugs.
6.Release clips and disconnect the bypass hose
and top hose.
7.Release harness from cable tie.
8.Disconnect oxygen sensor multiplug.
9.Release harness lead from cable tie.
10.Release throttle cable from abutment bracket.
11.Release throttle cable from cam. Also remove
coolant bypass hose from throttle housing.
12.Disconnect stepper motor and throttle
potentiometer multiplugs.
13.Release clip and disconnect hose, air cleaner to
throttle housing.

12ENGINE
16
REPAIR 14.Release clip and disconnect brake servo hose
from manifold.
15.Disconnect fuel temperature sensor multiplug.
16.Remove 3 bolts securing engine harness to
manifold.
17.Disconnect fuel injection harness multiplug.
18.Disconnect inlet manifold air temperature sensor
multiplug.
19.Release clip and disconnect fuel hose from
pressure regulator.
CAUTION: Plug the connections
20.Release clips and disconnect 3 hoses from
manifold.
21.Remove bolt securing dipstick tube to coolant
rail.

12ENGINE
18
REPAIR Refit
1.Fit location dowels to cylinder head.
2.Fit cylinder head gasket to cylinder block.
3.Using assistance fit cylinder head to cylinder
block.
4.Lubricate cylinder head bolts.
5.Fit and tighten cylinder head bolts to the correct
torque and in the correct sequence.
NOTE: For torque values.See
Specifications, torque, Torque values
6.Fit timing belt.
7.Fit camshaft covers.
8.Fit spark plug leads to spark plugs and secure to
clips.
9.Fit spark plug cover and secure with screws.
10.Fit new gasket and secure downpipe to exhaust
manifold with nuts.
11.Fit bolt securing dipstick tube to coolant rail.
12.Connect 3 vacuum hoses to inlet manifold.
13.Connect fuel to pressure regulator, secure with
clip.
14.Connect fuel injection harness, inlet manifold air
temperature sensor and fuel temperature sensor
multiplugs.
15.Secure engine harness to manifold with bolts.
16.Connect brake servo hose to manifold, secure
with clip.
17.Connect air cleaner hose to throttle housing,
secure with clip.
18.Connect stepper motor and throttle
potentiometer multiplugs.
19.Fit and adjust throttle cable.
20.Connect oxygen sensor multiplug, secure with
cable tie.
21.Connect the bypass and top hose, secure with
clips.
22.Connect coolant temperature sensor multiplugs,
secure with cable tie.
23.Connect hose to heater rail and secure with clip.
24.Connect radiator bottom hose and secure with
clip.
25.Tighten fuel pipe to fuel rail union.
26.Reconnect battery negative lead.

Mpi
1
SPECIFICATIONS, TORQUE TORQUE VALUES
NOTE: Torque wrenches should be regularly checked for accuracy to ensure that all fixings are
tightened to the correct torque.
Nm
ENGINE
Timing belt upper cover bolts 5......................................................................
Timing belt centre cover bolts 5.....................................................................
Timing belt lower cover bolts 5......................................................................
Crankshaft pulley centre bolt 85.....................................................................
Crankshaft pulley to timing gear bolts 10........................................................
Tensioner pulley bolt 30..................................................................................
Spark plugs 27................................................................................................
Timing belt upper backplate bolts 10..............................................................
Camshaft gear bolts 65...................................................................................
Exhaust camshaft rear oil seal cover plate bolts 10........................................
Inlet camshaft rear oil seal cover plate bolts 10..............................................
Crankshaft rear oil seal housing bolts 10........................................................
Engine sump bolts
Stage 1 3...............................................................................................
Stage 2 10..............................................................................................
Bell housing nuts 40........................................................................................
L.H. and R.H. engine mounting nuts 85..........................................................
Exhaust manifold to downpipe nuts 10...........................................................
Exhaust downpipe to silencer box nuts 30......................................................
Air conditioning compressor to engine block bolts 45.....................................
Cylinder head bolts
Stage 1 45..............................................................................................
Stage 2 80..............................................................................................
Stage 3 - Further 90°
Camshaft cover bolts 10.................................................................................
Knock sensor 15.............................................................................................
Ignition coil bracket bolts 25............................................................................
Coolant temperature sensor 15......................................................................
Crankshaft sensor bolts 7..............................................................................
Fuel temperature sensor 7.............................................................................
Intake air temperature sensor 7.....................................................................
Fuel rail to inlet manifold bolts 10...................................................................
Fuel feed hose stiffening bracket bolts 7.......................................................
Throttle housing mounting nuts 7...................................................................
Fuel pressure regulator steady bracket bolts 7..............................................
Oxygen sensor 55...........................................................................................

17EMISSION CONTROL
2
FAULT DIAGNOSISADD: 09/95 DRIVE CYCLE - ADVANCED EVAPS
1.Switch on ignition for 30 seconds.
2.Ensure that coolant temperature is less than 140
°F (30°C).
3.Start engine and allow to idle for 2 minutes.
4.Perform 2 light accelerations (0 to 35 mph with
light pedal pressure).
5.Perform 2 medium accelerations (0 to 45 mph
with moderate pedal pressure).
6.Perform 2 hard accelerations (0 to 55 mph with
heavy pedal pressure).
7.Cruise at 60 mph for 5 minutes.
8.Cruise at 50 mph for 5 minutes.
9.Cruise at 35 mph for 5 minutes.
10.Allow engine to idle for 2 minutes.
11.Connect TestBook and check for fault codes.

Tdi
1
DESCRIPTION AND OPERATION DESCRIPTION
Air intake
The air cleaner is positioned to the right of the engine
and connected by hoses to a cold air intake duct and
the turbocharger inlet. A crankcase breather hose is
fitted between the air cleaner and the separator.
A single stage turbocharger, fitted between the
exhaust manifold and exhaust pipe, is connected by
hoses to the air cleaner and to an intercooler mounted
on the right of the radiator. The intercooler is
connected by a hose to the inlet manifold.
Fuel system
A 89 litre fuel tank is mounted at the rear of the
vehicle beneath the load space floor. The tank is
vented by a 2 way valve in the filler cap.
A mechanical lift pump, driven by the camshaft, is
mounted on the side of the engine.
A fuel filter, fitted with a replaceable element and
incorporating a water separator, is positioned on the
LH side of the bulkhead.
A Bosch Type injection pump, incorporating a cold
start advance unit and a high idle setting is mounted
on the LH side of the engine and is directly driven by
gears from the crankshaft. The pump meters and
distributes fuel to 4 pintle type injectors located in
pre-combustion chambers in the cylinder heads.
A return line passes excess fuel from the injection
pump and injectors back to the fuel tank.
Glow plugs
Four glow plugs are located in the cylinder head,
directly below each injector.Exhaust gas recirculation (EGR)
Exhaust gas recirculation is controlled by the EGR
control unit mounted in the passenger compartment
on the RH 'A' post behind the fascia and receives the
following inputs:
a. Engine temperature from coolant temperature
transmitter in No. 4 cylinder head.
b. Throttle position from the sensor on the injection
pump.
c. Engine speed from the tachometer.
d. EGR valve lift position.
When all correct signals are received, the EGR
solenoid allows vacuum to open the EGR valve and
recirculate a portion of the exhaust gas.

19FUEL SYSTEM
2
DESCRIPTION AND OPERATION FUEL SYSTEM LAYOUT
1. Fuel tank
2. Fuel lift pump
3. Fuel filter
4. Fuel injection pump
5. Spill return line
6. Fuel injectors
7. Sediment plug
FUEL SYSTEM COMPONENT LOCATION
1. Fuel filter bleed screw
2. Fuel filter
3. Turbocharger
4. Wastegate
5. Air cleaner
6. Fuel injector
7. Glow plug
8. Glow plug controller
9. EGR valve and valve lift position sensor
10. Coolant temperature transmitter - EGR and instruments
11. Fuel injection pump
12. EGR throttle position sensor
13. Fuel lift pump
14. Intercooler
15. EGR Control unit

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.