jump start JAGUAR XJ6 1997 2.G User Guide

11Reconnect the vacuum hose to the
regulator and check the fuel pressure at idle,
comparing your reading with the value listed
in this Chapter’s Specifications. Disconnect
the vacuum hose and watch the gauge - the
pressure should jump up considerably as
soon as the hose is disconnected. If it
doesn’t, check for a vacuum signal to the fuel
pressure regulator (see Step 14).
12If the fuel pressure is low, pinch the fuel
return line shut (see illustration)and watch
the gauge. If the pressure doesn’t rise, the
fuel pump is defective or there is a restriction
or leak in the fuel feed line, or the pump is
faulty. If the pressure rises sharply, renew the
pressure regulator.
13If the fuel pressure is too high, turn the
engine off. Disconnect the fuel return line and
blow through it to check for a blockage. If
there is no blockage, renew the fuel pressure
regulator.
14Connect a vacuum gauge to the pressure
regulator vacuum hose. Start the engine and
check for vacuum (see illustration). The fuel
pressure regulator receives manifold vacuum
that decreases (increases fuel pressure) when
the engine speed is raised (acceleration). If
there isn’t vacuum present, check for a
clogged hose or vacuum port. If the amount ofvacuum is adequate but the pressure is too
high, renew the fuel pressure regulator.
15Turn the ignition switch to OFF, wait five
minutes and recheck the pressure on the
gauge. Compare the reading with the
specified hold pressure. If the hold pressure is
less than specified:
a) The fuel lines may be leaking.
b) The fuel pressure regulator may be
allowing the fuel pressure to bleed
through to the return line.
c) A fuel injector (or injectors) may be
leaking.
d) The fuel pump may be defective.
4 Fuel pump-
removal and refitting
3
Warning: Petrol is extremely
flammable, so take extra
precautions when you work on
any part of the fuel system. See
the Warning in Section 2.
Note 1:On early models (1988 to 1990), an
electric fuel pump is attached to the chassis
next to the fuel tank. On later models (1991 to
1994), the fuel pump is inside the fuel tank.
Note 2: On 1988 to 1990 models, the fuel
pump may chatter excessively and the engine
may stall frequently during hot weather. If
stalling occurs, the engine will restart after a
cool-down period. Dual fuel pumps can be
installed by a dealer service department or
other qualified repair facility to remedy this
problem.
1Remove the fuel tank filler cap to relieve
any pressure in the fuel tank. Relieve the fuel
pressure (see Section 2).
2Disconnect the cable from the negative
terminal of the battery.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
External fuel pumps
3Raise the vehicle and support it securely on
axle stands.
4Disconnect the fuel lines from the fuel pump.
5Disconnect the electrical connectors from
the fuel pump (see illustration 3.4a).
6Remove the fuel pump bracket retaining
nuts (see illustration).
7Carefully withdraw the fuel pump from the
rubber case inside the fuel pump bracket and
angle the fuel pump over the rear suspension
and out near the wheel on the left side of the
vehicle.
8Refitting is the reverse of removal.
In-tank fuel pumps
9Raise the vehicle and support it securely on
axle stands.
10Disconnect the fuel pump and fuel level
sender unit electrical connectors and the fuel
lines.
11Remove the fuel tank from the boot (see
Section 7).
12Disconnect the fuel lines from the evap-
orative flange (see illustration). Remove the
lock ring with a hammer and brass punch,
tapping the lock ring anti-clockwise.
13Withdraw the fuel pump module from the
fuel tank. Note: The fuel pump module is
4•4 Fuel and exhaust systems
3.14 Connect a vacuum gauge to the
vacuum line leading to the fuel pressure
regulator and check the vacuum source4.6 Remove the fuel pump mounting nuts
(arrowed) and slide the fuel pump out of
the rubber casing (1989 model shown)
3261 Jaguar XJ6 3.9 Check fuel pressure without vacuum applied to the fuel
pressure regulator, then with vacuum applied; fuel pressure
should DECREASE as vacuum INCREASES
3.12 Using a pair of pliers, squeeze the return line and observe
the fuel pressure increase (wrap a rag around the fuel line so you
don’t damage it)

3261 Jaguar XJ6
5
Chapter 5
Engine electrical systems
Ignition system
Ignition timing (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Not adjustable
Ignition coil resistance (at 68°F):
Primary resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.4 to 0.5 ohms
Secondary resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 to 6.5 k-ohms
Charging system
Charging voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.9 to 15.1 volts
Standard amperage:
No load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Less than 10 amps
Full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 amps or more Amplifier - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Alternator - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Battery cables - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . 4
Battery check, maintenance and charging . . . . . . . . . . . See Chapter 1
Battery - emergency jump starting . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Battery - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Charging system - check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Charging system - general information and precautions . . . . . . . . . 10
CHECK ENGINE light . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 6
Distributor - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Drivebelt check, adjustment and renewal . . . . . . . . . . . See Chapter 1General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Ignition coil - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Ignition system - check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Ignition system - general information and precautions . . . . . . . . . . . 5
Spark plug renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Spark plug lead, distributor cap and rotor check
and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Starter motor - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 15
Starter motor - testing in vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Starter solenoid - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 16
Starting system - general information and precautions . . . . . . . . . . 13
5•1
Specifications Contents
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
54321
1 General information
The engine electrical systems include all
ignition, charging and starting components.
Because of their engine related functions,
these components are discussed separately
from chassis electrical devices such as the
fuses, relays, lights, etc. (which are included in
Chapter 12).
Always observe the following precautions
when working on the electrical systems:
a) Be extremely careful when servicing
engine electrical components. They are
easily damaged if checked, connected or
handled improperly.
b) Never leave the ignition switch on for long
periods of time (10 minutes maximum)
with the engine off.c) Don’t disconnect the battery cables while
the engine is running.
d) Maintain correct polarity when connecting
a battery cable from another vehicle
during jump starting.
e) Always disconnect the negative cable first
and hook it up last or the battery may be
shorted by the tool being used to loosen
the cable clamps.
It’s also a good idea to review the safety-
related information regarding the engine
electrical systems in the Safety first section
near the front of this manual before beginning
any operation included in this Chapter.
2 Battery-
emergency jump starting
1
See “Jump starting”in “Roadside repairs”
at the front of this Manual.
3 Battery- removal and refitting
1
1Disconnect the negative terminal, then the
positive terminal from the battery. On 1989 to
1992 models, the battery is located in the
engine compartment on the passenger side
bulkhead and on 1993 and 1994 models, it is
located in the boot.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
2Remove the battery hold-down clamp.
3Lift out the battery. Be careful, it’s heavy.
4While the battery is out, inspect the carrier
(tray) for corrosion.
5If you are replacing the battery, make sure
that you get one that’s identical, with the

8After the alternator is installed, adjust the
drivebelt tension (see Chapter 1).
9Check the charging voltage to verify proper
operation of the alternator (see Section 11).
13 Starting system- general
information and precautions
The sole function of the starting system is
to crank the engine over quickly enough to
allow it to start.
The starting system consists of the battery,
the starter motor, the starter solenoid, the
starter relay and the electrical circuit
connecting the components. The solenoid is
mounted directly on the starter motor.
The solenoid/starter motor assembly is
installed on the upper part of the engine, next
to the transmission bellhousing.
When the ignition key is turned to the
START position, the starter solenoid is
actuated through the starter control circuit.
The starter solenoid then connects the battery
to the starter. The battery supplies the
electrical energy to the starter motor, which
does the actual work of cranking the engine.
The starter on a vehicle equipped with an
automatic transmission can be operated only
when the transmission selector lever is in Park
or Neutral.
These vehicles are equipped with either a
Bosch or Lucas starter assembly. The Lucas
unit is distinguished by the separate earth
strap from the solenoid to the starter body.
Bosch starter assemblies are equipped with a
solid metal earthing bar.
The starting system circuit is equipped with
a relay. The relay allows the ignition switch to
power the starter solenoid.
Always observe the following precautions
when working on the starting system:
a) Excessive cranking of the starter motor
can overheat it and cause serious
damage. Never operate the starter motor
for more than 15 seconds at a time
without pausing to allow it to cool for at
least two minutes.
b) The starter is connected directly to the
battery and could arc or cause a fire if
mishandled, overloaded or short circuited.
c) Always detach the cable from the
negative terminal of the battery before
working on the starting system.
Caution:If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
14 Starter motor-
testing in vehicle
2
1Make sure that the battery is charged and
that all cables, both at the battery and starter
solenoid terminals, are clean and secure.2If the starter motor does not turn at all when
the switch is operated, make sure that the
shift lever is in Neutral or Park (automatic
transmission) or that the clutch pedal is
depressed (manual transmission).
3If the starter motor spins but the engine is
not cranking, the overrunning clutch in the
starter motor is slipping and the starter motor
must be renewed.
4If, when the switch is actuated, the starter
motor does not operate at all but the solenoid
clicks, then the problem lies with either the
battery, the main solenoid contacts or the
starter motor itself (or the engine is seized).
5If the solenoid plunger cannot be heard
when the switch is actuated, the battery is
bad, the in-line fuse is burned (the circuit is
open), the starter relay (see illustration)is
defective or the starter solenoid itself is
defective.
6To check the solenoid, connect a jumper
lead between the battery (+) and the ignition
switch terminal (the small terminal) on the
solenoid. If the starter motor now operates,
the solenoid is OK and the problem is in the
ignition switch, linear switch (1988 to 1992),
rotary switch (1993 and 1994) or in the wiring.
7If the starter motor still does not operate,
remove the starter/solenoid assembly for
dismantling, testing and repair.
8If the starter motor cranks the engine at an
abnormally slow speed, first make sure that
the battery is charged and that all terminalconnections are tight. If the engine is partially
seized, or has the wrong viscosity oil in it, it
will crank slowly.
9Run the engine until normal operating
temperature is reached, then disconnect the
coil wire from the distributor cap and earth it
on the engine.
10Connect a voltmeter positive lead to the
battery positive post and connect the
negative lead to the negative post.
11Crank the engine and take the voltmeter
readings as soon as a steady figure is
indicated. Do not allow the starter motor to
turn for more than 15 seconds at a time. A
reading of nine volts or more, with the starter
motor turning at normal cranking speed, is
normal. If the reading is nine volts or more but
the cranking speed is slow, the motor is faulty.
If the reading is less than nine volts and the
cranking speed is slow, the solenoid contacts
are probably burned, the starter motor is bad,
the battery is discharged or there is a bad
connection.
15 Starter motor-
removal and refitting
2
1Detach the cable from the negative terminal
of the battery.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
2Raise the vehicle and support it securely
using axle stands.
3Drain the transmission fluid (see Chapter 7)
and remove the transmission fluid filler tube
from the transmission.
4Detach the electrical connectors from the
starter/solenoid assembly (see illustrations).
5Place a trolley jack under the tail section of
the transmission, remove the rear trans-
mission mount (see Chapter 7) and lower the
transmission slightly to gain access to the
upper transmission bellhousing bolts. Using
an extension with a swivel socket, remove the
upper starter mounting bolt (see illustration).
Engine electrical systems 5•7
5
14.5 With the ignition key ON (engine not
running), check for battery voltage to the
starter relay
15.4a Disconnect the solenoid electrical
connector at the harness connector
located near the bulkhead behind the
cylinder head (arrowed)15.4b From underneath the vehicle,
remove the battery terminal from the
solenoid (cylinder head removed
for clarity)
3261 Jaguar XJ6

3261 Jaguar XJ6
12
Chapter 12
Body electrical system
1 General information
The electrical system is a 12-volt, negative
earth type. Power for the lights and all
electrical accessories is supplied by a
lead/acid-type battery which is charged by
the alternator.
This Chapter covers repair and service
procedures for the various electrical
components not associated with the engine.
Information on the battery, alternator,
distributor and starter motor will be found in
Chapter 5.
It should be noted that when portions of the
electrical system are serviced, the cable
should be disconnected from the negative
battery terminal to prevent electrical shorts
and/or fires.
2 Electrical fault finding-
general information
A typical electrical circuit consists of an
electrical component, any switches, relays,
motors, fuses, fusible links, in-line fuses or
circuit breakers related to that component
and the wiring and electrical connectors that
link the component to both the battery andthe chassis. To help you pinpoint an electrical
circuit problem, wiring diagrams are included
at the end of this Chapter.
Before tackling any troublesome electrical
circuit, first study the appropriate wiring
diagrams to get a complete understanding of
what makes up that individual circuit. Trouble
spots, for instance, can often be narrowed
down by noting if other components related to
the circuit are operating properly. If several
components or circuits fail at one time,
chances are the problem is in a fuse or earth
connection, because several circuits are often
routed through the same fuse and earth
connections.
Electrical problems usually stem from
simple causes, such as loose or corroded
connections, a blown fuse, a melted fusible
link or a bad relay. Visually inspect the
condition of all fuses, wires and connections
in a problem circuit before diagnosing it.
If testing instruments are going to be
utilised, use the diagrams to plan ahead of
time where you will make the necessary
connections in order to accurately pinpoint
the trouble spot.
The basic tools needed for electrical fault
finding include a circuit tester or voltmeter (a
12-volt bulb with a set of test leads can also
be used), a continuity tester, which includes a
bulb, battery and set of test leads, and a
jumper wire, preferably with a circuit breaker
incorporated, which can be used to bypasselectrical components. Before attempting to
locate a problem with test instruments,
use the wiring diagram(s) to decide where to
make the connections.
Voltage checks
Voltage checks should be performed if a
circuit is not functioning properly. Connect
one lead of a circuit tester to either the
negative battery terminal or a known good
earth. Connect the other lead to a electrical
connector in the circuit being tested,
preferably nearest to the battery or fuse. If the
bulb of the tester lights, voltage is present,
which means that the part of the circuit
between the electrical connector and the
battery is problem free. Continue checking the
rest of the circuit in the same fashion. When
you reach a point at which no voltage is
present, the problem lies between that point
and the last test point with voltage. Most of
the time the problem can be traced to a loose
connection. Note:Keep in mind that some
circuits receive voltage only when the ignition
key is in the Accessory or Run position.
Finding a short
One method of finding shorts in a circuit is
to remove the fuse and connect a test light or
voltmeter in its place. There should be no
voltage present in the circuit. Move the wiring
harness from side to side while watching the
test light. If the bulb goes on, there is a short Airbag system - general information . . . . . . . . . . . . . . . . . . . . . . . . . 28
Bulb renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Central locking system - description and check . . . . . . . . . . . . . . . . 25
Circuit breakers - general information . . . . . . . . . . . . . . . . . . . . . . . . 5
Cruise control system - description and check . . . . . . . . . . . . . . . . . 23
Direction indicators/hazard flashers - general information . . . . . . . . 7
Electric aerial - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 14
Electric side view mirrors - description and check . . . . . . . . . . . . . . 26
Electric sunroof - description and check . . . . . . . . . . . . . . . . . . . . . . 27
Electric window system - description and check . . . . . . . . . . . . . . . 24
Electrical fault finding - general information . . . . . . . . . . . . . . . . . . . 2
Fuel, oil and temperature gauges - check . . . . . . . . . . . . . . . . . . . . . 11
Fuses - general information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Headlight housing (1992 to 1994 models) - removal and refitting . . . 19Headlights - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Headlights - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Heated rear window - check and repair . . . . . . . . . . . . . . . . . . . . . . 16
Horn - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Ignition switch and key lock cylinder - removal and refitting . . . . . . 9
Inertia switch - description and check . . . . . . . . . . . . . . . . . . . . . . . . 22
In-line fuses - general information . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Instrument cluster - removal and refitting . . . . . . . . . . . . . . . . . . . . . 12
Instrument panel switches - removal and refitting . . . . . . . . . . . . . . 10
Radio and speakers - removal and refitting . . . . . . . . . . . . . . . . . . . 13
Relays - general information and testing . . . . . . . . . . . . . . . . . . . . . . 6
Steering column switches - removal and refitting . . . . . . . . . . . . . . . 8
Windscreen wiper motor - removal and refitting . . . . . . . . . . . . . . . . 15
Wiring diagrams - general information . . . . . . . . . . . . . . . . . . . . . . . 29
12•1
Contents
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
54321

8Adjustment should be made with the
vehicle parked 25 feet from the wall, sitting
level, the petrol tank half-full and no unusually
heavy load in the vehicle.
9Starting with the low beam adjustment,
position the high intensity zone so it is two
inches below the horizontal line and two
inches to the right of the headlight vertical
line. Adjustments are made by turning the
knobs located behind the headlight housings
(see illustration 18.2).
10With the high beams on, the high intensity
zone should be vertically centred with the
exact centre just below the horizontal line.
Note:It may not be possible to position the
headlight aim exactly for both high and low
beams. If a compromise must be made, keep
in mind that the low beams are the most used
and have the greatest effect on safety.
11Have the headlights adjusted by a dealer
service department or service station at the
earliest opportunity.
19 Headlight housing
(1992 to 1994 models)-
removal and refitting
1
Warning: These vehicles are
equipped with halogen gas-filled
headlight bulbs which are under
pressure and may shatter if the
surface is damaged or the bulb is dropped.
Wear eye protection and handle the bulbs
carefully, grasping only the base whenever
possible. Do not touch the surface of the
bulb with your fingers because the oil from
your skin could cause it to overheat and
fail prematurely. If you do touch the bulb
surface, clean it with rubbing alcohol.
1Remove the headlight bulb (Section 17).
2Remove the retaining nuts, detach the
housing and withdraw it from the vehicle (see
illustration).
3Refitting is the reverse of removal.
20 Horn- check and renewal
2
Check
Note:Check the fuses before beginning
electrical diagnosis.
1Disconnect the electrical connector from
the horn.
2To test the horn, connect battery voltage to
the two terminals with a pair of jumper wires.
If the horn doesn’t sound, renew it.
3If the horn does sound, check for voltage at
the terminal when the horn button is
depressed (see illustration). If there’s voltage
at the terminal, check for a bad earth at the
horn.
4If there’s no voltage at the horn, check the
relay (see Section 6). Note that most horn
relays are either the four-terminal or externally
earthed three-terminal type.
5If the relay is OK, check for voltage to the
relay power and control circuits. If either of the
circuits are not receiving voltage, inspect the
wiring between the relay and the fuse panel.
6If both relay circuits are receiving voltage,
depress the horn button and check the circuit
from the relay to the horn button for continuityto earth. If there’s no continuity, check the
circuit for an open. If the circuit is good, renew
the horn button.
7If there’s continuity to earth through the
horn button, check for an open or short in the
circuit from the relay to the horn.Renewal
8Remove the radiator grille inserts (see
Chapter 11).
9Disconnect the electrical connector and
remove the retaining nuts securing the horn
brackets (see illustration).
10Refitting is the reverse of removal.
21 Bulb renewal
1
Front direction indicator/rear
parking and side marker lights
1Remove the lens retaining screws and the
lens (see illustration).
2Push inward and rotate the bulb anti-
clockwise to remove it from the holder.
3Renew the bulb, refit the lamp lens and test
the bulb operation.
Body electrical system 12•11
12
20.9 Disconnect the electrical connector,
remove the retaining nuts (arrowed) - then
detach the horn(s)21.1 The front direction indicator/rear
parking and side marker light bulbs are
accessible after removing the lens screws
3261 Jaguar XJ6 19.2 Remove the headlight housing retaining nuts (arrowed) from
the backside of the radiator support
20.3 Check for power at the horn terminal with the horn button
depressed

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

3261 Jaguar XJ6
IndexREF•23
EEarth check - 12•2
ECU -6•2
EGR gas temperature sensor -6•7
Electric shock -0•5
Electric windows - 12•13
Electrical equipment -1•14, REF•9
Electrical system fault finding - 12•1, REF•17
Electronic control system and ECU -4•9, 6•2
Electronic Fuel Injection (EFI) system -4•9, 4•10
Emissions and engine control systems-6•1et seq
Engine electrical systems-5•1et seq
Engine in-car repair procedures-2A•1et seq
Engine fault finding - ref•13,ref•14
Engine oil -0•11, 0•16, 1•2, 1•6
Engine removal and overhaul procedures-2B•1et seq
Environmental considerations - REF•5
Evaporative Emission Control (EVAP) system -6•10
Evaporator and expansion valve -3•14
Exhaust emission checks - REF•11
Exhaust Gas Recirculation (EGR) system -6•9
Exhaust manifolds -2A•4
Exhaust system -1•11, 4•2, 4•14, REF•10
Expansion tank -3•4, 3•5
FFans -3•3
Fault finding- REF•12et seq
ABS -9•2
automatic transmission - 7•1, REF•15
brakes - REF•15, REF•16
cooling system - REF•14
electrical system - 12•1, REF•17
engine - REF•13, REF•14
fuel system - REF•14
suspension and steering systems - REF•16, REF•17
Filling (bodywork repair) - 11•2
Filters
automatic transmission fluid - 1•19
fuel - 1•15
oil - 1•6
Fire -0•5
Fluids -0•16
Fuel and exhaust systems-4•1et seq, REF•11
Fuel filter -1•15
Fuel gauge - 12•7
Fuel pressure relief -4•2
Fuel system fault finding - REF•14
Fume or gas intoxication -0•5
Fuses -0•15, 12•2
GGaiters - 10•9
Gashes - 11•2
Gaskets - REF•5
Glass - 11•3, 11•10, 11•11, 12•13
Glossary of technical terms- REF•3, REF•18et seq
Glove box - 11•13
Grille - 11•5
HHandbrake -1•12, 1•20, 9•1, 9•10, 9•11, REF•8
Handles - 11•9, 11•10
Hazard flasher - 12•4
HC emissions - REF•11
Headlights -1•18, 12•9, 12•10, 12•11
Heated rear window - 12•8
Heater -3•2, 3•7, 3•9, 3•10, 3•11, 3•12
High-mounted brake light - 12•12
Hinges - 11•3
Horn - 12•11
Hoses -1•10
Hub bearings - 1•17, 10•8
Hydraulic system -0•16
Hydrofluoric acid -0•5
IIdle Speed Control (ISC) motor -4•11
Ignition switch - 12•6
Ignition system -1•15
In-tank fuel pumps -4•4
Indicators - 12•4, 12•11, 12•12
Inertia switch -4•1, 12•12
Information sensors -6•3
Injectors -4•12
Instruments - 1•14, 11•12, 12•6, 12•7, 12•12
Intake Air Temperature (IAT) sensor -6•7
Intake manifold -2A•4
Interior lights - 12•12
Introduction -0•4
JJacking - REF•1
Joint mating faces - REF•5
Jump starting -0•7
KKickdown cable -7•2
Knee bolster - 11•13
LLatch - 11•4, 11•7, 11•9
Leaks -0•9, 1•10, 7•2
Locknuts,locktabs and washers - REF•5
Locks - 11•3, 11•7, 11•9, 12•6
Lubricants -0•16
MMain bearings -2B•13, 2B•16
Manifolds -2A•4
Manual valve -7•7
Mass Airflow (MAF) sensor -6•6
Master cylinder -9•6
Mirrors - 11•11, 12•14, REF•8
MOT test checks- REF•8et seq
Mounts -2A•18, 7•8
Multi Point Fuel Injection (MPFI) system -4•1