1997 JAGUAR XJ6 water pump

5 Air Injector Reactor
(AIR) system
General information
1The air injection reactor system reduces
carbon monoxide and hydrocarbon content
in the exhaust gases by injecting fresh air into
the hot exhaust gases leaving the exhaust
ports. When fresh air is mixed with hot
exhaust gases, oxidation is increased,
reducing the concentration of hydrocarbons
and carbon monoxide and converting them
into harmless carbon dioxide and water.
2The air injection system is composed of an
air pump, diverter valve (bypass), check valve,
air injection manifold, vacuum delay valve,
vacuum control solenoid, air pump magnetic
clutch, air pump clutch relay and hoses (see
illustration). The air pump is driven by a belt
from the crankshaft and supplies compressed
air to the exhaust manifold(s). The check valve
prevents the reverse flow of exhaust gases into
the system. The vacuum-operated (early
models) or electrically-operated (later models)air cut-off valve prevents air from being drawn
into the exhaust when the air pump is switched
off. System vacuum to the air cut-off valve is
controlled by the solenoid vacuum valve in
parallel circuit with the air pump. A delay valve
prevents vacuum loss to the solenoid valve
during wide open throttle operation.
3Injected air is controlled by the computer,
the air pump clutch and the air pump clutch
relay. The AIR system is used during warm-up
(58 to 83° F) to control emissions while the
engine is running rich. The oxygen sensor
feedback system cannot function while the AIR
system is operating. The computer controls
both systems during warm-up and operating
temperatures. If problems occur with the
AIR system relay or circuit, the on-board
diagnosis system will set a code 66.
Check
4Check the condition of the air pump
drivebelt, the injection hoses and the injection
manifold. Make sure that all components are
intact and there are no leaks.
5Check the operation of the air pump clutch
relay (see illustration)and the air pump
clutch. First remove the relay and check forbattery voltage to the relay. Also, check the
relay itself. Refer to the relay checking
procedure in Chapter 12. Extract codes from
the self-diagnosis system (see Section 3) and
check for a code 66, AIR relay malfunction.
6Make sure the electrical connector is
securely fastened to the diverter valve (see
illustration). If everything appears OK but a
fault code still sets, have the system
diagnosed by a dealer service department or
other qualified repair workshop.
Air pump renewal
7Disconnect 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.
8Disconnect the electrical connector from
the air pump clutch.
9Loosen the clips from the air inlet and outlet
hose and separate them from the air injection
pump.
10Loosen the adjuster and pivot bolts (see
illustration)and nuts but do not remove them
from the air injection pump brackets.
6•8 Emissions and engine control systems
3261 Jaguar XJ6 5.2 Schematic of the Air Injection Reactor (AIR) system
5.6 Location of the AIR diverter valve on a 1992 model - check the
hoses for cracking and the electrical connector for security5.10 Loosen the pivot bolt and then the adjustment nut to remove
the drivebelt from the air pump. The adjustment nut has a lock bolt
that must be loosened before the pump will move down the adjuster
5.5 Location of the AIR pump relay on a 1992 model

6Carefully check to make sure the
suspension and steering components do not
make contact with the hoses. Have an
assistant push on the vehicle and also turn the
steering wheel from lock-to-lock during
inspection.
7Bleed the brake system (see Section 9).
Metal brake line renewal
8When replacing brake lines, use the proper
parts only. Do not use copper line for any
brake system connections. Purchase steel
brake lines from a dealer or motor factors..
9Unless you’re using factory renewal brake
lines, you may need a tubing bender to bend
the lines to the proper shape.
10First, remove the line you intend to renew,
lay it on a clean workbench and measure it
carefully. Obtain a new line of the same length
and bend it to match the pattern of the old
line.
Warning: Do not crimp or
damage the line. No bend should
have a smaller radius than
9/16-inch. Make sure the
protective coating on the new line is
undamaged at the bends.
11When refitting the new line, make sure it’s
well supported by the brackets, the routing
matches the original and there’s plenty of
clearance between moving or hot
components.
12After refitting, check the master cylinder
fluid level and add fluid as necessary. Bleed
the brake system as outlined in Section 9 and
test the brakes carefully before driving the
vehicle. Be sure there are no leaks.
9 Brake hydraulic system-
bleeding
2
Warning: Wear eye protection
when bleeding the brake
system. If the fluid comes in
contact with your eyes,
immediately rinse them with water and
seek medical attention.Note:Bleeding the hydraulic system is
necessary to remove any air which has entered
the system during removal and refitting of a
hose, line, caliper or master cylinder.
1It will probably be necessary to bleed the
system at all four brakes if air has entered the
system due to low fluid level or if the brake
lines have been disconnected at the master
cylinder.
2If a brake line was disconnected at only one
wheel, then only that caliper or wheel cylinder
must be bled.
3If a brake line is disconnected at a fitting
located between the master cylinder and any
of the brakes, that part of the system served
by the disconnected line must be bled.
4Bleed the right rear, the left rear, the right
front and the left front caliper, in that order,
when the entire system is involved.
5Remove any residual vacuum from the
servo and pressure in the anti-lock braking
system (if equipped) by applying the brake
about 30 times with the engine off.
6Remove the master cylinder reservoir cover
and fill the reservoir with brake fluid. Refit the
cover. Note:Check the fluid level often during
the bleeding operation and add fluid as
necessary to prevent the fluid level from falling
low enough to allow air into the master
cylinder.
7Have an assistant on hand, as well as a
supply of new brake fluid, an empty clear
plastic container, a length of 3/16-inch clear
tubing to fit over the bleed screws and a
spanner to open and close the bleed screws.
8Beginning at the right rear wheel, loosen the
bleed screw slightly, then tighten it to a point
where it is snug but can still be loosened
quickly and easily.
9Place one end of the tubing over the bleed
valve and submerge the other end in brake
fluid in the container (see illustration).
10Have the assistant pump the brakes a few
times to build pressure in the system, then
hold the pedal firmly depressed.
11While the pedal is held depressed, open
the bleed screw just enough to allow fluid to
flow from the caliper. Watch for air bubbles toexit the submerged end of the tube. When the
fluid flow slows after a couple of seconds,
close the screw and have your assistant
release the pedal.
12Repeat Steps 10 and 11 until no more air
is seen leaving the tube, then tighten the
bleed screw and proceed to the left rear
wheel, the right front wheel and the left
front wheel, in that order, and perform the
same procedure. Be sure to check the fluid in
the master cylinder reservoir frequently.
13Never reuse old brake fluid. It contains
contaminates and moisture which could
damage the braking system.
14Refill the master cylinder with fluid at the
end of the operation.
15Check the operation of the brakes. The
pedal should feel solid when depressed, with
no sponginess. If necessary, repeat the entire
process.
Warning: Do not drive the car if
in doubt about the effectiveness
of the brake system.
10 Handbrake cable-
adjustment
1
1Slowly apply the handbrake and count the
number of clicks at the lever. It should be fully
applied within three to five clicks. If the lever is
still not fully applied by the fifth click, adjust
the handbrake cable as follows:
2Raise the vehicle and place it securely on
axle stands.
3Loosen the locknut (see illustration)and
tighten the cable adjuster until all slack has
been removed. Tighten the locknut. Make
sure the wheels turn freely with the handbrake
lever released
4Lower the vehicle and recheck the
handbrake lever. It should now be properly
adjusted. If it’s now fully applied within three
to five clicks, raise the vehicle again and
readjust the cable at the adjuster.
5Make sure the handbrake holds the vehicle
on an incline.
9•10 Braking system
8.3b The connection (arrowed) for the rear
hose and line is located right above the
mounting bracket for the front corner of
the differential crossmember; remove the
hose as described in the previous
illustration9.9 When bleeding the brakes, a hose is
connected to the bleed screw at the caliper
or wheel cylinder and then submerged in
brake fluid - air will be seen as bubbles in
the tube and container (all air must be
expelled before moving to the next brake)
10.3 To adjust the handbrake cable,
loosen the locknut, then turn the adjuster
to remove any slack in the cable; be sure
to tighten the locknut when the cable is
properly adjusted
3261 Jaguar XJ6

3261 Jaguar XJ6
Fault findingREF•13
1 Engine
Engine will not rotate when attempting to start
m mBattery terminal connections loose or corroded (Chapter 1).
m mBattery discharged or faulty (Chapter 1).
m mDamaged left rear window harness shorting against glass rail
inside door, causing battery to drain (Chapter 12).
m mAutomatic transmission not completely engaged in Park
(Chapter 7).
m mBroken, loose or disconnected wiring in the starting circuit
(Chapters 5 and 12).
m mStarter motor pinion jammed in flywheel ring gear (Chapter 5).
m mStarter solenoid faulty (Chapter 5).
m mStarter motor faulty (Chapter 5).
m mIgnition switch faulty (Chapter 12).
m mStarter pinion or flywheel teeth worn or broken (Chapter 5).
m mInternal engine problem (Chapter 2B).
m mInertia switch activated (Chapter 12).
m mStarter relay defective (Chapter 5).
Engine rotates but will not start
m
mFuel tank empty.
m mBattery discharged (engine rotates slowly) (Chapter 5).
m mBattery terminal connections loose or corroded (Chapter 1).
m mLeaking fuel injector(s), faulty fuel pump, pressure regulator, etc.
(Chapter 4).
m mFuel not reaching fuel injection system (Chapter 4).
m mIgnition components damp or damaged (Chapter 5).
m mFuel injector stuck open (Chapter 4).
m mWorn, faulty or incorrectly gapped spark plugs (Chapter 1).
m mBroken, loose or disconnected wiring in the starting circuit
(Chapter 5).
m mLoose distributor is changing ignition timing (Chapter 1).
m mBroken, loose or disconnected wires at the ignition coil or faulty
coil (Chapter 5).
m m1988 and 1989 models may have electrical connector damage
between the fuel pump relay and the fuel pump (Chapter 12).
m mCoolant temperature sensor shorting on bonnet liner (Chapter 11).
m mDefective Mass Airflow (MAF) sensor (Chapter 6).
Engine hard to start when cold
m
mBattery discharged or low (Chapter 1).
m mFuel system malfunctioning (Chapter 4).
m mInjector(s) leaking (Chapter 4).
m mDistributor rotor carbon tracked (Chapter 5).
m mWater enters the air cleaner housing near the left front wheel arch
(Chapter 4).
Engine hard to start when hot
m mAir filter clogged (Chapter 1).
m mFuel not reaching the fuel injection system (Chapter 4).
m mCorroded battery connections, especially ground (Chapter 1).
m mFuel vaporises at fuel pump inlet. Refit dual fuel pumps
(Chapter 4).
m mFuel vapours from charcoal canister enter intake during idle and
cause idling, stalling and starting problems (Chapter 6).
Starter motor noisy or excessively rough in
engagement
m mPinion or flywheel gear teeth worn or broken (Chapter 5).
m mStarter motor mounting bolts loose or missing (Chapter 5).
Engine starts but stops immediately
m
mLoose or faulty electrical connections at distributor, coil or
alternator (Chapter 5).
m mInsufficient fuel reaching the fuel injector(s) (Chapters 1 and 4).
m mDamaged fuel injection system speed sensors (Chapter 5).
m mFaulty fuel injection relays (Chapter 5).
m mLeaking threaded adapter on the EGR valve - where fitted
(Chapter 6)
Oil puddle under engine
m mSump gasket and/or sump drain bolt seal leaking (Chapter 2).
m mOil pressure sending unit leaking (Chapter 2).
m mValve cover gaskets leaking (Chapter 2).
m mEngine oil seals leaking (Chapter 2).
m mCylinder head rear plate gasket leaking (Chapter 2).
m mAlternator mounting bolt threads leaking oil (Chapter 5).
m mOil cooler or oil cooler lines leaking (Chapter 3).
Engine misses while idling or idles erratically
m
mVacuum leakage (Chapter 2).
m mAir filter clogged (Chapter 1).
m mFuel pump not delivering sufficient fuel to the fuel injection system
(Chapter 4).
m mLeaking head gasket (Chapter 2).
m mTiming belt/chain and/or sprockets worn (Chapter 2).
m mCamshaft lobes worn (Chapter 2).
m mEGR valve stuck open - where fitted (Chapter 6).
Engine misses at idle speed
m
mSpark plugs worn or not gapped properly (Chapter 1).
m mFaulty spark plug leads (Chapter 1).
m mVacuum leaks (Chapter 1).
m mIncorrect ignition timing (Chapter 5).
m mUneven or low compression (Chapter 2).
m mRestricted EGR vacuum hose - where fitted (Chapter 6).
Engine misses throughout driving speed range
m
mFuel filter clogged and/or impurities in the fuel system (Chapter 1).
m mLow fuel output at the injectors (Chapter 4).
m mFaulty or incorrectly gapped spark plugs (Chapter 1).
m mIncorrect ignition timing (Chapter 5).
m mCracked distributor cap, disconnected distributor wires or
damaged distributor components (Chapter 1).
m mLeaking spark plug leads (Chapter 1).
m mFaulty emission system components (Chapter 6).
m mLow or uneven cylinder compression pressures (Chapter 2).
m mWeak or faulty ignition system (Chapter 5).
m mVacuum leak in fuel injection system, intake manifold or vacuum
hoses (Chapter 4).
m mCrankshaft sensor teeth damaged or missing (see Chapter 12).
m mDistributor installed incorrectly (see Chapter 5)
Engine stumbles on acceleration
m
mSpark plugs fouled (Chapter 1).
m mFuel injection system malfunctioning (Chapter 4).
m mFuel filter clogged (Chapters 1 and 4).
m mIncorrect ignition timing (Chapter 5).
m mIntake manifold air leak (Chapter 4).
m mCollapsed or damaged fuel tank caused by blocked EVAP system
- where fitted (see Chapter 6).

3261 Jaguar XJ6
REF•14Fault finding
2 Fuel system
Engine surges while holding accelerator steady
m mIntake air leak (Chapter 4).
m mFuel pump faulty (Chapter 4).
m mLoose fuel injector harness connections (Chapters 4 and 6).
m mDefective ECU (Chapter 6).
Pinking or knocking engine sounds during
acceleration or uphill
m mIncorrect grade of fuel.
m mDistributor installed incorrectly (Chapter 5).
m mFuel injection system in need of adjustment (Chapter 4).
m mImproper or damaged spark plugs or wires (Chapter 1).
m mWorn or damaged distributor components (Chapter 5).
m mFaulty emission system (Chapter 6).
m mVacuum leak (Chapter 4).
m mFuel rail feed (inlet) hose has hardened, resulting in knocking noise
near dash (see Chapter 4).
Engine lacks power
m mIncorrect ignition timing (Chapter 5).
m mExcessive play in distributor shaft (Chapter 5).
m mWorn rotor, distributor cap or wires (Chapters 1 and 5).
m mFaulty or incorrectly gapped spark plugs (Chapter 1).
m mFuel injection system malfunctioning (Chapter 4).
m mFaulty coil (Chapter 5).
m mBrakes binding (Chapter 1).
m mAutomatic transmission fluid level incorrect (Chapter 1).
m mFuel filter clogged and/or impurities in the fuel system (Chapter 1).
m mEmission control system not functioning properly (Chapter 6).
m mLow or uneven cylinder compression pressures (Chapter 2).
Engine rattles at start-up
m
mFailure of upper timing chain tensioner (Chapter 2).
Engine backfires
m
mEmissions system not functioning properly (Chapter 6).
m mIgnition timing incorrect (Chapter 1).
m mFaulty secondary ignition system (cracked spark plug insulator,
faulty plug leads, distributor cap and/or rotor) (Chapters 1 and 5).
m mFuel injection system malfunctioning (Chapter 4).
m mVacuum leak at fuel injector(s), intake manifold or vacuum hoses
(Chapter 4).
Engine stalls
m mIdle speed incorrect (Chapter 1).
m mFuel filter clogged and/or water and impurities in the fuel system
(Chapter 1).
m mDistributor components damp or damaged (Chapter 5).
m mFaulty emissions system components (Chapter 6).
m mFaulty or incorrectly gapped spark plugs (Chapter 1).
m mFaulty spark plug leads (Chapter 1).
m mVacuum leak in the fuel injection system, intake manifold or
vacuum hoses (Chapter 4).
Engine runs with oil pressure light on
m mLow oil level (Chapter 1).
m mIdle rpm too low (Chapter 1).
m mShort in wiring circuit (Chapter 12).
m mFaulty oil pressure sending unit (Chapter 2).
m mWorn engine bearings and/or oil pump (Chapter 2).
Engine diesels (continues to run)
after switching off
m mIdle speed too high (Chapter 4).
m mExcessive engine operating temperature (Chapter 3).
m mIncorrect fuel octane grade.
Excessive fuel consumption
m
mDirty or clogged air filter element (Chapter 1).
m mIncorrectly set ignition timing (Chapter 5).
m mEmissions system not functioning properly (Chapter 6).
m mFuel injection internal parts worn or damaged (Chapter 4).
m mLow tyre pressure or incorrect tyre size (Chapter 1).
Fuel leakage and/or fuel odour
m
mLeak in a fuel feed or vent line (Chapter 4).
m mTank overfilled.
m mFuel injector internal parts excessively worn (Chapter 4).
3 Cooling system
Overheating
m
mInsufficient coolant in system (Chapter 1).
m mWater pump drivebelt defective or out of adjustment (Chapter 1).
m mRadiator core blocked or grille restricted (Chapter 3).
m mThermostat faulty (Chapter 3).
m mRadiator cap not maintaining proper pressure (Chapter 3).
m mIgnition timing incorrect (Chapter 5).
Overcooling
m
mFaulty thermostat (Chapter 3).
External coolant leakage
m
mDeteriorated/damaged hoses; loose clamps (Chapters 1 and 3).
m mWater pump seal defective (Chapters 1 and 3).
m mLeakage from radiator core or manifold tank (Chapter 3).
m mEngine drain or water jacket core plugs leaking (Chapter 2).
m mHoses behind water pump leaking (Chapter 3).
Internal coolant leakage
m
mLeaking cylinder head gasket (Chapter 2).
m mCracked cylinder bore or cylinder head (Chapter 2).
Coolant loss
m
mToo much coolant in system (Chapter 1).
m mCoolant boiling away because of overheating (Chapter 3).
m mInternal or external leakage (Chapter 3).
m mFaulty radiator cap (Chapter 3).
Poor coolant circulation
m
mInoperative water pump (Chapter 3).
m mRestriction in cooling system (Chapters 1 and 3).
m mWater pump drivebelt defective/out of adjustment (Chapter 1).
m mThermostat sticking (Chapter 3).
1 Engine (continued)

3261 Jaguar XJ6
Glossary of technical termsREF•19
Catalytic converterA silencer-like device in
the exhaust system which converts certain
pollutants in the exhaust gases into less
harmful substances.
CirclipA ring-shaped clip used to prevent
endwise movement of cylindrical parts and
shafts. An internal circlip is installed in a
groove in a housing; an external circlip fits into
a groove on the outside of a cylindrical piece
such as a shaft.
ClearanceThe amount of space between
two parts. For example, between a piston and
a cylinder, between a bearing and a journal,
etc.
Coil springA spiral of elastic steel found in
various sizes throughout a vehicle, for
example as a springing medium in the
suspension and in the valve train.
CompressionReduction in volume, and
increase in pressure and temperature, of a
gas, caused by squeezing it into a smaller
space.
Compression ratioThe relationship between
cylinder volume when the piston is at top
dead centre and cylinder volume when the
piston is at bottom dead centre.
Constant velocity (CV) jointA type of
universal joint that cancels out vibrations
caused by driving power being transmitted
through an angle.
Core plugA disc or cup-shaped metal device
inserted in a hole in a casting through which
core was removed when the casting was
formed. Also known as a freeze plug or
expansion plug.
CrankcaseThe lower part of the engine
block in which the crankshaft rotates.
CrankshaftThe main rotating member, or
shaft, running the length of the crankcase,
with offset “throws” to which the connecting
rods are attached.
Crocodile clipSee Alligator clipDDiagnostic codeCode numbers obtained by
accessing the diagnostic mode of an engine
management computer. This code can be
used to determine the area in the system
where a malfunction may be located.
Disc brakeA brake design incorporating a
rotating disc onto which brake pads are
squeezed. The resulting friction converts the
energy of a moving vehicle into heat.
Double-overhead cam (DOHC)An engine
that uses two overhead camshafts, usually
one for the intake valves and one for the
exhaust valves.
Drivebelt(s)The belt(s) used to drive
accessories such as the alternator, water
pump, power steering pump, air conditioning
compressor, etc. off the crankshaft pulley.
DriveshaftAny shaft used to transmit
motion. Commonly used when referring to the
axleshafts on a front wheel drive vehicle.
Drum brakeA type of brake using a drum-
shaped metal cylinder attached to the inner
surface of the wheel. When the brake pedal is
pressed, curved brake shoes with friction
linings press against the inside of the drum to
slow or stop the vehicle.
EEGR valveA valve used to introduce exhaust
gases into the intake air stream.
Electronic control unit (ECU)A computer
which controls (for instance) ignition and fuel
injection systems, or an anti-lock braking
system. For more information refer to the
Haynes Automotive Electrical and Electronic
Systems Manual.
Electronic Fuel Injection (EFI)A computer
controlled fuel system that distributes fuel
through an injector located in each intake port
of the engine.
Emergency brakeA braking system,
independent of the main hydraulic system,
that can be used to slow or stop the vehicle if
the primary brakes fail, or to hold the vehicle
stationary even though the brake pedal isn’t
depressed. It usually consists of a hand lever
that actuates either front or rear brakes
mechanically through a series of cables and
linkages. Also known as a handbrake or
parking brake.EndfloatThe amount of lengthwise
movement between two parts. As applied to a
crankshaft, the distance that the crankshaft
can move forward and back in the cylinder
block.
Engine management system (EMS)A
computer controlled system which manages
the fuel injection and the ignition systems in
an integrated fashion.
Exhaust manifoldA part with several
passages through which exhaust gases leave
the engine combustion chambers and enter
the exhaust pipe.
F
Fan clutchA viscous (fluid) drive coupling
device which permits variable engine fan
speeds in relation to engine speeds.
Feeler bladeA thin strip or blade of hardened
steel, ground to an exact thickness, used to
check or measure clearances between parts.
Firing orderThe order in which the engine
cylinders fire, or deliver their power strokes,
beginning with the number one cylinder.
Flywheel A heavy spinning wheel in which
energy is absorbed and stored by means of
momentum. On cars, the flywheel is attached
to the crankshaft to smooth out firing
impulses.
Free playThe amount of travel before any
action takes place. The “looseness” in a
linkage, or an assembly of parts, between the
initial application of force and actual
movement. For example, the distance the
brake pedal moves before the pistons in the
master cylinder are actuated.
FuseAn electrical device which protects a
circuit against accidental overload. The typical
fuse contains a soft piece of metal which is
calibrated to melt at a predetermined current
flow (expressed as amps) and break the
circuit.
Fusible linkA circuit protection device
consisting of a conductor surrounded by
heat-resistant insulation. The conductor is
smaller than the wire it protects, so it acts as
the weakest link in the circuit. Unlike a blown
fuse, a failed fusible link must frequently be
cut from the wire for replacement.Catalytic converter
Crankshaft assembly
Accessory drivebelts
Feeler blade

3261 Jaguar XJ6
WWasher fluid -0•12
Water pump -3•6
Weekly checks-0•10et seq
Weights - REF•1
Wheel alignment -1•18, 10•11
Wheel bearings -1•17, 10•8, REF•10
Wheel changing -0•8Wheels - 10•11, REF•11
Windows - 11•10, 11•11, 12•13
Windscreen - 11•3, REF•8
Wing - 11•6
Wiper blades -0•13
Wiper motor - 12•8
Wiring diagrams- 12•15et seq
Working facilities- REF•7
IndexREF•25