fuel LAND ROVER DISCOVERY 1995 Repair Manual

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...........................................................................................

EMISSION CONTROL
1
DESCRIPTION AND OPERATION REV: 09/95 EMISSION CONTROL
Three systems are used to control the vehicle
atmospheric emissions these are:
Engine crankcase fume emissions.
Fuel tank Evaporative emissions
Engine exhaust gas emissions.
Crankcase ventilation system - 3.9 MFi models
only
The crankcase ventilation system which is an integral
part of the air supply to the engine combustion
chambers, is often overlooked when diagnosing
problems associated with engine performance. A
blocked ventilation pipe or filter or excessive air leak
into the inlet system through a damaged pipe or
leaking gasket can effect the mixture, performance
and economy of the engine.
1. Three way connector
2. Air filter
3. Oil separatorThe purpose of the crankcase ventilation system is to
ensure that any noxious gas generated in the engine
crankcase is rendered harmless by burning in the
combustion chambers as follows:
Oil laden noxious gas in the engine crankcase is
drawn through an oil separator 3 located on the right
cylinder head rocker cover, where the oil is separated
and returned to the sump. The gas flows through a
restrictor in the three way connection 1 and into the
inlet plenum chamber where it is drawn into the
combustion chambers and burned. The volume of
fresh air which is drawn from the atmospheric side of
the throttle butterfly to mix with the gas, depends on
the position of the throttle and the engine speed.
The air filter 2 fitted to the left cylinder head rocker
cover, must be maintained in clean condition to
ensure sufficient air enters the crankcase under
varying throttle openings and manifold depression, to
prevent excessive crankcase pressure or depression
developing.

17EMISSION CONTROL
2
DESCRIPTION AND OPERATION REV: 09/95 Exhaust emission control.
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
conditions of operation. 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, according to conditions, to
correct any unsatisfactory composition of the exhaust.
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, oxides of nitrogen, and hydrocarbons. The
active constituents of the converters are platinum and
rhodium. The correct functioning of the converters is
dependent upon close control of the oxygen
concentration in the exhaust gas entering the catalyst.
The oxygen content of the exhaust gas is monitored
by the heated oxygen sensors. Information on the
heated oxygen sensors is contained in the relevant
Fuel System section,
See FUEL SYSTEM MFI,
Description and operation, or See FUEL SYSTEM
SFI, Description and operation,
The ECM can then
make an appropriate adjustment to the fuel supply to
correct the composition of the exhaust.
CAUTION: Unleaded fuel only must be
used on vehicles fitted with catalytic
converters. As a reminder,a label to
indicate this is adhered to the inside of the fuel
filler flap. Furthermore the filler neck is designed
to accommodate only unleaded fuel pump
nozzles.

17EMISSION CONTROL
4
DESCRIPTION AND OPERATION REV: 09/95 Evaporative emission control system - pre
advanced EVAPS.
The system is designed to prevent harmful fuel vapour
from escaping to the atmosphere. The system
consists of a vapour separator tank, connected to the
fuel tank and located between the body inner and
outer panels on the right hand side of the vehicle near
the rear wheel arch. An adsorbtion canister,
containing activated charcoal, is positioned in the
engine compartment attached to the front right
valance. The two components are connected by a
pipe running the length of the chassis.
A Pressure relief to atmosphere.
B From fuel tank to separator.
C To adsorbtion canister.
D Pressure relief valve.
E Pressure relief valve.
F Shut-off valve.
G "Speed Fit" connectors.A pressure relief valve is fitted in the hose which is
open to atmosphere. This valve acts as a safety valve
should a build-up of pressure occur in the system, for
example if a hose became blocked or kinked. The
volume of vapour emitted, in such an instance, would
be acceptable.
A pressure relief valve is also fitted in the hose
connected to the adsorbtion canister and releases
vapor to the canister when the pressure in the
separator reaches between 5 and 7 Kpa.
In the top of the separator a shut-off valve is
incorporated in the vapor exit port to prevent the
possible presence of any liquid fuel being transmitted
to the adsorbtion canister should the vehicle roll over.
The adsorbtion canister, which is connected by a hose
to the plenum chamber, absorbs and stores the fuel
vapour from the fuel tank while the engine is not
running. When the engine is started, the vapour is
purged from the canister by air drawn through an
orifice in the base of the canister and by the influence
of vacuum at the top. The vapour drawn into the
plenum chamber through a solenoid operated purge
valve is finally burnt in the combustion chambers.
The purge valve, which is attached to the adsorbtion
canister support bracket, is controlled by the Engine
Control Module ECM which determines the most
emission acceptable time at which purging should
take place. This will normally be at engine speeds
above idle and when the vehicle is in motion. A signal
from the ECM to the purge valve operates the
solenoid and opens the valve to purge the canister of
fuel vapour.

EMISSION CONTROL
5
DESCRIPTION AND OPERATION REV: 09/95 EVAPORATIVE CONTROL SYSTEM - PRE
ADVANCED EVAPS
1. Adsorption canister and purge valve.
2. Location of vapour separator and pipes.
3. Fuel tank.

17EMISSION CONTROL
6
DESCRIPTION AND OPERATION ADD: 09/95 EVAPORATIVE EMISSION CONTROL SYSTEM -
ADVANCED EVAPS
Component location
1.EVAP canister
2.EVAP canister vent solenoid (ECVS)
3.EVAP canister purge valve
4.Anti-trickle fill valve
5.Liquid/vapour separator
6.Fuel filler neck assembly
7.Fuel tank
8.Fuel pump and gauge sender unit

EMISSION CONTROL
7
DESCRIPTION AND OPERATION ADD: 09/95
Fuel filler neck components
A Anti-trickle fill valve
B Liquid/Vapour Separator
C Vent line to pressure sensor
D From fuel tank to liquid/vapour separator
E From EVAP canister to anti-trickle fill valve
F Fuel filler hose, Dual layer, convolute nylon
G Fuel tank internal breather hoseIdentification
The system was introduced on all North American
specification vehicles from October 1996 and the
vehicles can be recognised by the information
contained in theEVAP. FAMILYentry on the
underbonnet Emission label (mounted on the vertical
face of the bonnet lock platform).
A - Vehicles with advanced EVAPS
VLR1124AYPFE
B - Vehicles without advanced EVAPS
VLR1060AYPBC

17EMISSION CONTROL
8
DESCRIPTION AND OPERATION ADD: 09/95 System operation
The system is designed to prevent fuel vapour
escaping to atmosphere, and consists of four roll-over
valves fitted internally in the fuel tank, connected to
the liquid/vapour separator by a nylon line. The
separator is mounted to the side of the filler neck. An
EVAP canister is positioned in the engine
compartment mounted on the right front side valance.
The liquid/vapour separator and EVAP canister are
connected by a nylon line which runs the length of the
chassis.
Pressure/vacuum relief valves are incorporated into
the fuel filler cap and are designed to protect the fuel
tank from permanent deformation in the event of
system pressure or vacuum exceeding the system
operating parameters. There are no other relief or
one-way valves in the system.
A vent line flow restrictor known as an anti-trickle fill
valve is fitted to the filler pipe in the line between the
tank and EVAP canister. The function of this valve is
to prevent overfilling the tank by trickling fuel in,
thereby preserving the vapour space in the tank to
allow for fuel expansion during hot weather.
The valve achieves this by blocking the vent line
during the fuel filling process. The valve is operated
by the action of inserting the filler gun so that when
the fuel in the tank reaches the level of the filling
breather, flow cut off occurs due to fuel filling the filler
pipe.During normal vehicle operation and when the engine
is switched off, the venting system between the fuel
tank and EVAP canister is open to allow the free
passage of vapour.
The EVAP canister, which is connected by a nylon
hose to the plenum chamber, absorbs and stores the
fuel vapour from the fuel tank when the engine is not
running. With the engine running, vapour is purged
from the EVAP canister by allowing outside air to be
drawn through the EVAP canister vent solenoid and
link pipe by the influence of manifold vacuum to the
EVAP canister purge connection on the canister.
Filter pads are fitted above and below the charcoal
and in the EVAP canister vent solenoid to prevent the
ingress of foreign matter into the purge line.
The EVAP canister purge valve, which is fitted in the
line from the EVAP canister to the plenum, is
controlled by the ECM which determines the most
emission acceptable time at which purging should
take place. This will normally be at engine speeds
above idle and when the vehicle is in motion.
The EVAP canister vent solenoid is mounted on the
side of the EVAP canister bracket and is connected to
the EVAP canister by a length of large bore hose. The
ECVS is controlled by the ECM and is normally open.
The function of the ECVS is to block the air intake
side of the EVAP canister. When the system receives
an ECM signal the valve closes; this allows the
system leak check to take place. The leak check only
occurs when pre-determined vehicle operating
conditions are met.