2002 LAND ROVER DISCOVERY fuel consumption

GENERAL DATA
04-8
Fuel system - Td5
Type Direct injection from pressure regulated supply with cooled return
flow and in-line pressure regulator
Pressure regulator setting 4 bar (58 lbf.in
2)
Pump Electric two stage submersible
Pump output:

Low pressure 30 l/h (6.6 gal/h) (7.93 US gal/h) at 0.5 bar (7.25 lbf.in
2)

High pressure 180 l/h (39.6 gal/h) (47.55 US gal/h) at 4 bar (58 lbf.in
2)
Maximum consumption 30 l/h (6.6 gal/h) (7.93 US gal/h)
Injectors Electronic unit injectors
Injector nominal operating pressure:

Pre EU3 models 1500 bar (21750 lbf.in
2)

EU3 models 1750 bar (25500 lbf.in
2)
Filter In-line canister filter/water separator with water detection
Air cleaner Mann and Hummell P0037

CAPACITIES, FLUIDS AND LUBRICANTS
09-3
Anti-Freeze Concentration
The overall anti-freeze concentration should not fall,
by volume, below 50% to ensure that the anti-
corrosion properties of the coolant are maintained.
Anti-freeze concentrations greater than 60% are not
recommended as cooling efficiency will be impaired.
The following recommended quantities of anti-freeze
will provide frost protection to -48
°C (-53°F):
Engine - TD5
Engine - V8
Lubrication
General
The engine and other lubricating systems are filled
with high-performance lubricants giving prolonged
life.
CAUTION: Always use a high quality oil of the
correct viscosity range in the engine. The use of
oil of the incorrect specification can lead to high
oil and fuel consumption and ultimately to
damaged components.
Oil to the correct specification contains additives
which disperse the corrosive acids formed by
combustion and prevent the formation of sludge
which can block the oil ways. Additional oil additives
should not be used.
Always adhere to the recommended servicing
intervals.
Engine oil viscosity
The above chart indicates the ambient temperature
ranges which each engine oil viscosity is suitable for.
Engine oil - V8 - low compression engine
Use a 10W/40 oil meeting specification ACEA: A2,
and having a viscosity band recommended for the
temperature range of your locality.
Concentration 50%
Amount of Anti-freeze 4 litres
Concentration 50%
Amount of Anti-freeze 6.5 litres
13.5 pts (US)

EMISSION CONTROL - V8
17-2-10 DESCRIPTION AND OPERATION
A spiral oil separator is located in the stub pipe to the ventilation hose on the right hand cylinder head rocker cover,
where oil is separated and returned to the cylinder head. The rubber ventilation hose from the right hand rocker cover
is routed to a port on the right hand side of the inlet manifold plenum chamber where the returned gases mix with the
fresh inlet air passing through the throttle butterfly valve. The stub pipe on the left hand rocker cover does not contain
an oil separator, and the ventilation hose is routed to the throttle body housing at the air inlet side of the butterfly valve.
The ventilation hoses are attached to the stub pipe by metal band clamps.
Exhaust emission control system
The fuel injection system provides accurately metered quantities of fuel to the combustion chambers to ensure the
most efficient air to fuel ratio under all operating conditions. A further improvement to combustion is made by
measuring the oxygen content of the exhaust gases to enable the quantity of fuel injected to be varied in accordance
with the prevailing engine operation and ambient conditions; any unsatisfactory composition of the exhaust gas is
then corrected by adjustments made to the fuelling by the ECM.
The main components of the exhaust emission system are two catalytic converters which are an integral part of the
front exhaust pipe assembly. The catalytic converters are included in the system to reduce the emission to
atmosphere of carbon monoxide (CO), oxides of nitrogen (NO
x) and hydrocarbons (HC). The active constituents of
the catalytic converters are platinum (Pt), palladium (PD) and rhodium (Rh). Catalytic converters for NAS low
emission vehicles (LEVs) from 2000MY have active constituents of palladium and rhodium only. The correct
functioning of the converters is dependent upon close control of the oxygen concentration in the exhaust gas entering
the catalyst.
The two catalytic converters are shaped differently to allow sufficient clearance between the body and transmission,
but they remain functionally identical since they have the same volume and use the same active constituents.
The basic control loop comprises the engine (controlled system), the heated oxygen sensors (measuring elements),
the engine management ECM (control) and the injectors and ignition (actuators). Other factors also influence the
calculations of the ECM, such as air flow, air intake temperature and throttle position. Additionally, special driving
conditions are compensated for, such as starting, acceleration, deceleration, overrun and full load.
The reliability of the ignition system is critical for efficient catalytic converter operation, since misfiring will lead to
irreparable damage of the catalytic converter due to the overheating that occurs when unburned combustion gases
are burnt inside it.
CAUTION: If the engine is misfiring, it should be shut down immediately and the cause rectified. Failure to do
so will result in irreparable damage to the catalytic converter.
CAUTION: Ensure the exhaust system is free from leaks. Exhaust gas leaks upstream of the catalytic
converter could cause internal damage to the catalytic converter.
CAUTION: Serious damage to the engine may occur if a lower octane number fuel than recommended is used.
Serious damage to the catalytic converter and oxygen sensors will occur if leaded fuel is used.
Air : fuel ratio
The theoretical ideal air:fuel ratio to ensure complete combustion and minimise emissions in a spark-ignition engine
is 14.7:1 and is referred to as the stoichiometric ratio.
The excess air factor is denoted by the Lambda symbol
λ, and is used to indicate how far the air:fuel mixture ratio
deviates from the theoretical optimum during any particular operating condition.
lWhen
λ = 1, the air to fuel ratio corresponds to the theoretical optimum of 14.7:1 and is the desired condition for
minimising emissions.
lWhen
λ > 1, (i.e. λ = 1.05 to λ = 1.3) there is excess air available (lean mixture) and lower fuel consumption can
be attained at the cost of reduced performance. For mixtures above
λ = 1.3, the mixture ceases to be ignitable.
lWhen
λ < 1, (i.e. λ = 0.85 to λ = 0.95) there is an air deficiency (rich mixture) and maximum output is available,
but fuel economy is impaired.
The engine management system used with V8 engines operates in a narrower control range about the stoichiometric
ideal between
λ = 0.97 to 1.03 using closed-loop control techniques. When the engine is warmed up and operating
under normal conditions, it is essential to maintain
λ close to the ideal (λ = 1) to ensure the effective treatment of
exhaust gases by the three-way catalytic converters installed in the downpipes from each exhaust manifold.

EMISSION CONTROL - V8
DESCRIPTION AND OPERATION 17-2-11
Changes in the oxygen content has subsequent effects on the levels of exhaust emissions experienced. The levels
of hydrocarbons and carbon monoxide produced around the stoichiometric ideal control range are minimised, but
peak emission of oxides of nitrogen are experienced around the same range.
Fuel metering
For a satisfactory combustion process, precise fuel injection quantity, timing and dispersion must be ensured. If the
air:fuel mixture in the combustion chamber is not thoroughly atomized and dispersed during the combustion stroke,
some of the fuel may remain unburnt which will lead to high HC emissions.
Ignition timing
The ignition timing can be changed to minimise exhaust emissions and fuel consumption in response to changes due
to the excess air factor. As the excess air factor increases, the optimum ignition angle is advanced to compensate for
delays in flame propagation.
Exhaust emission control components
The exhaust emission control components are described below:
Catalytic converter
1Exhaust gas from manifold
2Cleaned exhaust gas to tail pipe
3Catalytic converter outer case41st ceramic brick
52nd ceramic brick
6Honeycomb structure
The catalytic converters are located in each of the front pipes from the exhaust manifolds.

EMISSION CONTROL - V8
17-2-16 DESCRIPTION AND OPERATION
Fuel leak detection system (vacuum type) – NAS only
The advanced evaporative loss control system equipped with a vacuum type, fuel evaporation leak detection
capability is similar to the standard evaporative loss system, but also includes additional components to enable the
engine control module (ECM) to perform a fuel evaporation leak detection test. The system includes an EVAPs
canister and purge valve, and in addition, a canister vent solenoid (CVS) valve and a fuel tank pressure sensor.
The function of the CVS valve is to block the atmospheric vent side of the EVAP canister under the control of the ECM
so that an evaporation system leak check can be performed. The test is carried out when the vehicle is stationary and
the engine is running at idle speed. The system test uses the natural rate of fuel evaporation and engine manifold
depression. Failure of the leak check will result in illumination of the Malfunction Indicator Lamp (MIL).
The fuel evaporation leak detection is part of the On-Board Diagnostics (OBD) strategy and it is able to determine
vapour leaks from holes or breaks greater than 1 mm (0.04 in.) in diameter. Any fuel evaporation system leaks which
occur between the output of the purge valve and the connection to the inlet manifold cannot be determined using this
test, but these will be detected through the fuelling adaption diagnostics.
Fuel leak detection system (positive pressure type) – NAS only
The evaporative loss control system equipped with a positive pressure type, fuel evaporation leak detection capability
is similar to the vacuum type, but it is capable of detecting smaller leaks by placing the evaporation system under the
influence of positive air pressure. The system includes an EVAPs canister and purge valve, and in addition, a leak
detection pump comprising a motor and solenoid valve.
The solenoid valve contained in the leak detection pump assembly performs a similar function to the CVS valve
utilised on the vacuum type pressure test. The solenoid valve is used to block the atmospheric vent side of the EVAP
canister under the control of the ECM so that an EVAP system leak check can be performed. At the same time,
pressurised air from the pump is allowed past the valve into the EVAP system to set up a positive pressure. The test
is carried out at the end of a drive cycle when the vehicle is stationary and the ignition is switched off. The test is
delayed for a brief period (approximately 10 seconds) after the engine is switched off to allow any slosh in the fuel
tank to stabilise. Component validity checks and pressure signal reference checking takes a further 10 seconds before
the pressurised air is introduced into the EVAP system.
During reference checking, the purge valve is closed and the leak detection pump solenoid valve is not energised,
while the leak detection pump is operated. The pressurised air is bypassed through a restrictor which corresponds to
a 0.5 mm (0.02 in) leak while the current consumption of the leak detection pump motor is monitored.
The system test uses the leak detection pump to force air into the EVAP system when the purge valve and solenoid
valves are both closed (solenoid valve energised), to put the evaporation lines, components and fuel tank under the
influence of positive air pressure. Air is drawn into the pump through an air filter which is located in the engine
compartment.
The fuel leak detection pump current consumption is monitored by the ECM while the EVAP system is under pressure,
and compared to the current noted during the reference check. A drop in the current drawn by the leak detection pump
motor, indicates that air is being lost through holes or leaks in the system which are greater than the reference value
of 0.5 mm (0.02 in). An increase in the current drawn by the leak detection pump motor, indicates that the EVAP
system is well sealed and that there are no leaks present which are greater than 0.5 mm (0.02 in).
The presence of leakage points indicates the likelihood of hydrocarbon emissions to atmosphere from the
evaporation system outside of test conditions and the necessity for rectification work to be conducted to seal the
system. Failure of the leak check will result in illumination of the Malfunction Indicator Lamp (MIL).
C0637-9 Fuel tank pressure sensor (NAS vehicles
with vacuum type EVAP system leak
detection only)Output reference 5V
C0637-12 Analogue fuel level (NAS vehicles with
positive pressure type EVAP system leak
detection only)Input Analogue 0 - 5V
C0637-14 Fuel tank pressure sensor (NAS vehicles
with vacuum type EVAP system leak
detection only)Input signal Analogue 0 - 5V
C0637-20 MIL "ON" Output drive Switch to ground Connector / Pin No. Function Signal type Control

EMISSION CONTROL - V8
DESCRIPTION AND OPERATION 17-2-35
Failure of the closed loop control of the exhaust emission system may be attributable to one of the failure modes
indicated below:
lMechanical fitting & integrity of the sensor.
lSensor open circuit / disconnected.
lShort circuit to vehicle supply or ground.
lLambda ratio outside operating band.
lCrossed sensors.
lContamination from leaded fuel or other sources.
lChange in sensor characteristic.
lHarness damage.
lAir leak into exhaust system (cracked pipe / weld or loose fixings).
System failure will be indicated by the following symptoms:
lMIL light on (NAS and EU-3 only).
lDefault to open-loop fuelling for the defective cylinder bank.
lIf sensors are crossed, engine will run normally after initial start and then become progressively unstable with
one bank going to its maximum rich clamp and the other bank going to its maximum lean clamp – the system will
then revert to open-loop fuelling.
lHigh CO reading
lStrong smell of H
2S (rotten eggs)
lExcessive emissions
Fuel metering
When the engine is cold, additional fuel has to be provided to the air:fuel mixture to assist starting. This supplementary
fuel enrichment continues until the combustion chamber has heated up sufficiently during the warm-up phase.
Under normal part-throttle operating conditions the fuel mixture is adjusted to provide minimum fuel emissions and
the air:fuel mixture is held close to the optimum ratio (
λ = 1). The engine management system monitors the changing
engine and environmental conditions and uses the data to determine the exact fuelling requirements necessary to
maintain the air:fuel ratio close to the optimum value that is needed to ensure effective exhaust emission treatment
through the three-way catalytic converters.
During full-throttle operation the air:fuel mixture needs to be made rich to provide maximum torque. During
acceleration, the mixture is enriched by an amount according to engine temperature, engine speed, change in throttle
position and change in manifold pressure, to provide good acceleration response.
When the vehicle is braking or travelling downhill the fuel supply can be interrupted to reduce fuel consumption and
eliminate exhaust emissions during this period of operation.
If the vehicle is being used at altitude, a decrease in the air density will be encountered which needs to be
compensated for to prevent a rich mixture being experienced. Without compensation for altitude, there would be an
increase in exhaust emissions and problems starting, poor driveability and black smoke from the exhaust pipe. For
open loop systems, higher fuel consumption may also occur.

ENGINE MANAGEMENT SYSTEM - TD5
DESCRIPTION AND OPERATION 18-1-27
Clutch switch
The clutch switch is located at the rear of the engine compartment on the RH side. The switch is operated by hydraulic
pressure when the clutch pedal is pressed. The ECM uses the signal from the clutch switch for the following functions:
lTo cancel cruise control if operating.
lTo provide surge damping during gear change.
Surge damping stops engine speed rising dramatically (engine flaring) during gear change. Surge damping assists
driveability as follows:
lSmoother gear change.
lGreater exhaust gas emission control.
lImproved fuel consumption.
Input/Output
The clutch switch receives battery voltage from the BCU. With the clutch pedal in the rest position the switch is closed,
allowing battery voltage to pin 35 of the ECM connector C0658. When the clutch pedal is pressed the switch contacts
open, interrupting the power supply to the ECM. The ECM receives 0 Volts.
The clutch switch can fail in the following ways:
lSwitch open circuit.
lShort circuit to vehicle supply.
lShort circuit to earth.
In the event of a clutch switch failure the ECM will react as follows:
lSurge damping will be inactive.
lCruise control will be inactive.
High/Low ratio switch
Refer to transfer box for description of the high/low ratio switch.

+ TRANSFER BOX - LT230SE, DESCRIPTION AND OPERATION, Description.

ENGINE MANAGEMENT SYSTEM - TD5
18-1-32 DESCRIPTION AND OPERATION
Turbocharger
1Exhaust gas from manifold
2Studs to exhaust manifold
3Turbocharger cast iron housing
4Wastegate valve linkage
5Exhaust gas out to front exhaust pipe
6Compressed intake air
7Fresh intake air
8Turbocharger aluminium alloy housing
9Wastegate valve vacuum port
The Td5 engine utilises a Garrett GT20 turbocharger with an electronically controlled wastegate modulator to improve
engine performance. The turbocharger uses the engine's exhaust gas to spin a turbine at very high speed. This
causes inlet air on the other side of the turbine to be drawn in through the turbocharger intake for compression. The
inlet air is carried round by the vanes of the compressor and then thrown out under centrifugal force from the
turbocharger's outlet duct. This compression of air enables a greater quantity of air to be delivered to the inlet manifold
via an intercooler. Combustion is improved through better volumetric efficiency. The use of a turbocharger improves
fuel consumption and increases engine torque and power. Exhaust noise is also reduced due to the smoothing out of
exhaust pulsations.
The rear cast iron body of the turbocharger housing connects to a port on the exhaust manifold at the LH side of the
cylinder head by three studs and nuts. The interface between the exhaust manifold and the turbocharger housing is
separated by a metal gasket. The exhaust outlet of the turbocharger is located at the bottom of the turbocharger cast
iron housing; it is connected to the exhaust system front downpipe and is attached by three studs and nuts. The
interface between the turbocharger housing and the exhaust front pipe is separated by a metal gasket.
The front casing of the turbocharger is constructed from aluminium alloy and is connected to the air inlet duct by a
metal band clip. The compressed air outlet is connected to the intercooler by a metal pipe which has rubber hose
extensions at each end attached by metal band clips.