1997 JAGUAR XJ6 damper

13Allow the bellcrank to return to the idle
position and test the adjustment once again
until the correct adjustment has been attained.
11 Electronic Fuel Injection
(EFI) system-
general information
1These models are equipped with an
Electronic Fuel Injection (EFI) system. This fuel
injection system is designed by Bosch butlicensed by Lucas and is called the Lucas LH
Engine Management system. The EFI system
is composed of three basic sub systems: fuel
system, air induction system and electronic
control system (see illustration).
Fuel system
2An electric fuel pump is located on the
chassis of the rear suspension (external) (1988
to 1990) or inside the fuel tank (1991 to 1994)
The fuel pump supplies fuel under constant
pressure to the fuel rail, which distributes fuel
evenly to all injectors. From the fuel rail, fuel is
injected into the intake ports, just above the
intake valves, by fuel injectors. The amount of
fuel supplied by the injectors is precisely
controlled by an Electronic Control Unit (ECU).
A pressure regulator controls system pressure
in relation to intake manifold vacuum. A fuel
filter between the fuel pump and the fuel rail
filters fuel to protect the components of the
system.
Air induction system
3The air system consists of an air filter
housing, a Mass Air Flow (MAF) sensor
(airflow meter), Intake Air Temperature (IAT)
sensor and a throttle body. The MAF sensor is
an information gathering device for the ECU.A heated element determines the temperature
differential by measuring the current changes
which in turn measures the mass (weight and
volume) of air entering the engine. This
information helps the ECU determine the
amount of fuel to be injected by the injectors.
The throttle plate inside the throttle body is
controlled by the driver. As the throttle plate
opens, the amount of air that can pass
through the system increases, so the
potentiometer opens further and the ECU
signals the injectors to increase the amount of
fuel delivered to the intake ports. Refer to
Chapter 6 for additional information on the
fuel injection system sensors, test procedures
and renewal procedures.
Electronic control system
4The Computer Control System controls the
EFI and other systems by means of an
Electronic Control Unit (ECU), which employs
a microcomputer. The ECU receives signals
from a number of information sensors which
monitor such variables as intake air volume,
intake air temperature, coolant temperature,
engine rpm, acceleration/deceleration and
exhaust oxygen content. These signals help
the ECU determine the injection duration
necessary for the optimum air/fuel ratio. Some
Fuel and exhaust systems 4•9
4
10.11 Rotate the bellcrank until it reaches
wide open throttle and make sure the
pointer aligns with the A on the bellcrank.
Adjust if necessary
11.1 Fuel injection and emission control component locations for the 3.6 litre 1989 XJ6
3261 Jaguar XJ6 1 Fuel pressure regulator (under
fuel rail)
2 Idle Speed Control (ISC) motor
3 Fuel pressure damper4 Bellcrank
5 Throttle body (below bellcrank)
6 Intake Air Temp. (IAT) sensor
7 Supplementary air valve8 Mass Airflow (MAF) sensor
9 Throttle potentiometer (under
throttle body)
10 Fuel rail11 Fuel injector
13 Ignition amplifier (below block
valve)
14 Distributor

3261 Jaguar XJ6
Use of EnglishREF•3
As the main part of this book has been written in the US, it uses the appropriate US component names, phrases, and spelling. Some of these
differ from those used in the UK. Normally, these cause no difficulty, but to make sure, a glossary is printed below. When ordering spare parts,
remember the parts list may use some of these words:
AMERICAN ENGLISH
Aluminum Aluminium
Antenna Aerial
Authorized Authorised
Auto parts stores Motor factors
Axleshaft Halfshaft
Back-up Reverse
Barrel Choke/venturi
Block Chock
Box-end wrench Ring spanner
Bushing Bush
Carburetor Carburettor
Center Centre
Coast Freewheel
Color Colour
Convertible Drop head coupe
Cotter pin Split pin
Counterclockwise Anti-clockwise
Countershaft (of gearbox) Layshaft
Dashboard Facia
Denatured alcohol Methylated spirit
Dome lamp Interior light
Driveaxle Driveshaft
Driveshaft Propeller shaft
Fender Wing/mudguard
Firewall Bulkhead
Flashlight Torch
Float bowl Float chamber
Floor jack Trolley jack
Freeway, turnpike etc Motorway
Freeze plug Core plug
Frozen Seized
Gas tank Petrol tank
Gasoline (gas) Petrol
Gearshift Gearchange
Generator (DC) Dynamo
Ground (electrical) Earth
Header Exhaust manifold
Heat riser Hot spot
High Top gear
Hood (engine cover) Bonnet
Installation Refitting
Intake Inlet
Jackstands Axle stands
Jumper cable Jump lead
Keeper Collet
Kerosene Paraffin
Knock pin Roll pin
Lash Clearance
Lash Free-play
Latch Catch
Latches Locks
License plate Number plate
Light Lamp
Lock (for valve spring retainer) Split cotter (for valve spring cap)
Lopes Hunts
Lug nut/bolt Wheel nut/bolt
Metal chips or debris Swarf
Misses Misfires
AMERICAN ENGLISH
Muffler Silencer
Odor Odour
Oil pan Sump
Open flame Naked flame
Panel wagon/van Van
Parking brake Handbrake
Parking light Sidelight
Pinging Pinking
Piston pin or wrist pin Gudgeon pin
Piston pin or wrist pin Small end, little end
Pitman arm Drop arm
Power brake booster Servo unit
Primary shoe (of brake) Leading shoe (of brake)
Prussian blue Engineer’s blue
Pry Prise (force apart)
Prybar Lever
Prying Levering
Quarter window Quarterlight
Recap Retread
Release cylinder Slave cylinder
Repair shop Garage
Replacement Renewal
Ring gear (of differential) Crownwheel
Rocker panel (beneath doors) Sill panel (beneath doors)
Rod bearing Big-end bearing
Rotor/disk Disc (brake)
Secondary shoe (of brake) Trailing shoe (of brake)
Sedan Saloon
Setscrew, Allen screw Grub screw
Shock absorber, shock Damper
Snap-ring Circlip
Soft top Hood
Spacer Distance piece
Spare tire Spare wheel
Spark plug wires HT leads
Spindle arm Steering arm
Stabilizer or sway bar Anti-roll bar
Station wagon Estate car
Stumbles Hesitates
Tang or lock Tab washer
Throw-out bearing Thrust bearing
Tie-rod or connecting rod (of steering) Trackrod
Tire Tyre
Transmission Gearbox
Troubleshooting Fault finding/diagnosis
Trunk Boot (luggage compartment)
Turn signal Indicator
TV (throttle valve) cable Kickdown cable
Unpublicized Unpublicised
Valve cover Rocker cover
Valve lifter Tappet
Valve lifter or tappet Cam follower or tappet
Vapor Vapour
Vise Vice
Wheel cover Roadwheel trim
Whole drive line Transmission
Windshield Windscreen
Wrench Spanner

3261 Jaguar XJ6
REF•20Glossary of technical terms
GGapThe distance the spark must travel in
jumping from the centre electrode to the side
electrode in a spark plug. Also refers to the
spacing between the points in a contact
breaker assembly in a conventional points-
type ignition, or to the distance between the
reluctor or rotor and the pickup coil in an
electronic ignition.
GasketAny thin, soft material - usually cork,
cardboard, asbestos or soft metal - installed
between two metal surfaces to ensure a good
seal. For instance, the cylinder head gasket
seals the joint between the block and the
cylinder head.
GaugeAn instrument panel display used to
monitor engine conditions. A gauge with a
movable pointer on a dial or a fixed scale is an
analogue gauge. A gauge with a numerical
readout is called a digital gauge.
HHalfshaftA rotating shaft that transmits
power from the final drive unit to a drive
wheel, usually when referring to a live rear
axle.
Harmonic balancerA device designed to
reduce torsion or twisting vibration in the
crankshaft. May be incorporated in the
crankshaft pulley. Also known as a vibration
damper.
HoneAn abrasive tool for correcting small
irregularities or differences in diameter in an
engine cylinder, brake cylinder, etc.
Hydraulic tappetA tappet that utilises
hydraulic pressure from the engine’s
lubrication system to maintain zero clearance
(constant contact with both camshaft and
valve stem). Automatically adjusts to variation
in valve stem length. Hydraulic tappets also
reduce valve noise.
IIgnition timingThe moment at which the
spark plug fires, usually expressed in the
number of crankshaft degrees before the
piston reaches the top of its stroke.
Inlet manifoldA tube or housing with
passages through which flows the air-fuel
mixture (carburettor vehicles and vehicles with
throttle body injection) or air only (port fuel-
injected vehicles) to the port openings in the
cylinder head.
JJump startStarting the engine of a vehicle
with a discharged or weak battery by
attaching jump leads from the weak battery to
a charged or helper battery.
LLoad Sensing Proportioning Valve (LSPV)A
brake hydraulic system control valve that
works like a proportioning valve, but also
takes into consideration the amount of weight
carried by the rear axle.
LocknutA nut used to lock an adjustment
nut, or other threaded component, in place.
For example, a locknut is employed to keep
the adjusting nut on the rocker arm in
position.
LockwasherA form of washer designed to
prevent an attaching nut from working loose.
MMacPherson strutA type of front
suspension system devised by Earle
MacPherson at Ford of England. In its original
form, a simple lateral link with the anti-roll bar
creates the lower control arm. A long strut - an
integral coil spring and shock absorber - is
mounted between the body and the steering
knuckle. Many modern so-called MacPherson
strut systems use a conventional lower A-arm
and don’t rely on the anti-roll bar for location.
MultimeterAn electrical test instrument with
the capability to measure voltage, current and
resistance.
NNOxOxides of Nitrogen. A common toxic
pollutant emitted by petrol and diesel engines
at higher temperatures.
OOhmThe unit of electrical resistance. One
volt applied to a resistance of one ohm will
produce a current of one amp.
OhmmeterAn instrument for measuring
electrical resistance.
O-ringA type of sealing ring made of a
special rubber-like material; in use, the O-ring
is compressed into a groove to provide the
sealing action.
Overhead cam (ohc) engineAn engine with
the camshaft(s) located on top of the cylinder
head(s).Overhead valve (ohv) engineAn engine with
the valves located in the cylinder head, but
with the camshaft located in the engine block.
Oxygen sensorA device installed in the
engine exhaust manifold, which senses the
oxygen content in the exhaust and converts
this information into an electric current. Also
called a Lambda sensor.
PPhillips screwA type of screw head having a
cross instead of a slot for a corresponding
type of screwdriver.
PlastigageA thin strip of plastic thread,
available in different sizes, used for measuring
clearances. For example, a strip of Plastigage
is laid across a bearing journal. The parts are
assembled and dismantled; the width of the
crushed strip indicates the clearance between
journal and bearing.
Propeller shaftThe long hollow tube with
universal joints at both ends that carries
power from the transmission to the differential
on front-engined rear wheel drive vehicles.
Proportioning valveA hydraulic control
valve which limits the amount of pressure to
the rear brakes during panic stops to prevent
wheel lock-up.
RRack-and-pinion steeringA steering system
with a pinion gear on the end of the steering
shaft that mates with a rack (think of a geared
wheel opened up and laid flat). When the
steering wheel is turned, the pinion turns,
moving the rack to the left or right. This
movement is transmitted through the track
rods to the steering arms at the wheels.
RadiatorA liquid-to-air heat transfer device
designed to reduce the temperature of the
coolant in an internal combustion engine
cooling system.
RefrigerantAny substance used as a heat
transfer agent in an air-conditioning system.
R-12 has been the principle refrigerant for
many years; recently, however, manufacturers
have begun using R-134a, a non-CFC
substance that is considered less harmful to
the ozone in the upper atmosphere.
Rocker armA lever arm that rocks on a shaft
or pivots on a stud. In an overhead valve
engine, the rocker arm converts the upward
movement of the pushrod into a downward
movement to open a valve.
Adjusting spark plug gap
Plastigage
Gasket