fuel tank removal JAGUAR XJ6 1997 2.G Workshop Manual

6Refit the compression gauge in the spark
plug hole (see illustration).
7Crank the engine over at least seven
compression strokes and watch the gauge.
The compression should build up quickly in a
healthy engine. Low compression on the first
stroke, followed by gradually increasing
pressure on successive strokes, indicates
worn piston rings. A low compression reading
on the first stroke, which doesn’t build up
during successive strokes, indicates leaking
valves or a blown cylinder head gasket (a
cracked cylinder head could also be the
cause). Deposits on the undersides of the
valve heads can also cause low compression.
Record the highest gauge reading obtained.
8Repeat the procedure for the remaining
cylinders and compare the results to this
Chapter’s Specifications.
9Add some engine oil (about three squirts
from a plunger-type oil can) to each cylinder,
through the spark plug hole, and repeat the
test.
10If the compression increases after the oil
is added, the piston rings are definitely worn.
If the compression doesn’t increase
significantly, the leakage is occurring at the
valves or cylinder head gasket. Leakage past
the valves may be caused by burned valve
seats and/or faces or warped, cracked or bent
valves.
11If two adjacent cylinders have equally low
compression, there’s a strong possibility that
the cylinder head gasket between them is
blown. The appearance of coolant in the
combustion chambers or the crankcase
would verify this condition.
12If one cylinder is 20 percent lower than the
others, and the engine has a slightly rough
idle, a worn exhaust lobe on the camshaft
could be the cause.
13If the compression is unusually high, the
combustion chambers are probably coated
with carbon deposits. If that’s the case, the
cylinder head(s) should be removed and
decarbonised.
14If compression is way down or varies
greatly between cylinders, it would be a goodidea to have a leak-down test performed by
an automotive repair workshop. This test will
pinpoint exactly where the leakage is
occurring and how severe it is.
5 Engine removal-
methods and precautions
If you’ve decided that an engine must be
removed for overhaul or major repair work,
several preliminary steps should be taken.
Locating a suitable place to work is
extremely important. Adequate work space,
along with storage space for the vehicle, will
be needed. If a workshop or garage isn’t
available, at the very least a flat, level, clean
work surface made of concrete or asphalt is
required.
Cleaning the engine compartment and
engine before beginning the removal
procedure will help keep tools clean and
organised.
An engine hoist or A-frame will also be
necessary. Make sure the equipment is rated
in excess of the combined weight of the
engine and transmission. Safety is of primary
importance, considering the potential hazards
involved in lifting the engine out of the vehicle.
If the engine is being removed by a novice,
a helper should be available. Advice and aid
from someone more experienced would also
be helpful. There are many instances when
one person cannot simultaneously perform all
of the operations required when lifting the
engine out of the vehicle.
Plan the operation ahead of time. Arrange
for or obtain all of the tools and equipment
you’ll need prior to beginning the job. Some of
the equipment necessary to perform engine
removal and refitting safely and with relative
ease are (in addition to an engine hoist) a
heavy duty trolley jack, complete sets of
spanners and sockets as described in the
front of this manual, wooden blocks and
plenty of rags and cleaning solvent for
mopping up spilled oil, coolant and petrol. If
the hoist must be rented, make sure that you
arrange for it in advance and perform all of the
operations possible without it beforehand.
This will save you money and time.
Plan for the vehicle to be out of use for
quite a while. A machine workshop will be
required to perform some of the work which
the do-it-yourselfer can’t accomplish without
special equipment. These shops often have a
busy schedule, so it would be a good idea to
consult them before removing the engine in
order to accurately estimate the amount of
time required to rebuild or repair components
that may need work.
Always be extremely careful when removing
and refitting the engine. Serious injury can
result from careless actions. Plan ahead, take
your time and a job of this nature, although
major, can be accomplished successfully.
6 Engine- removal and refitting
3
Note:Read through the entire Section before
beginning this procedure. It is recommended
to remove the engine and transmission from
the top as a unit, then separate the engine
from the transmission on the workshop floor. If
the transmission is not being serviced, it is
possible to leave the transmission in the
vehicle and remove the engine from the top by
itself, by removing the crankshaft damper and
tilting up the front end of the engine for
clearance,but access to the upper
bellhousing bolts is only practical when the
rear transmission mount and driveshaft have
been removed and the transmission is angled
down with a trolley jack.
Removal
1Relieve the fuel system pressure (see
Chapter 4).
2Disconnect the battery negative cable.
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.
3Place protective covers on the wings and
cowl and remove the bonnet (see Chapter 11).
4Remove the battery and battery tray.
5Remove the air cleaner assembly (see
Chapter 4).
6Raise the vehicle and support it securely on
axle stands. Drain the cooling system and
engine oil and remove the drivebelts (see
Chapter 1).
7Clearly label, then disconnect all vacuum
lines, coolant and emissions hoses, wiring
harness connectors and earth straps.
Masking tape and/or a touch up paint
applicator work well for marking items (see
illustration). Take instant photos or sketch
the locations of components and brackets.
8Remove the cooling fan(s) and radiator (see
Chapter 3).
9Disconnect the heater hoses.
10Release the residual fuel pressure in the
tank by removing the petrol cap, then detach
the fuel lines connecting the engine to the
chassis (see Chapter 4). Plug or cap all open
fittings.
2B•4 Engine removal and overhaul procedures
4.6 A compression gauge with a threaded
fitting for the spark plug hole is preferred
over the type that requires hand pressure
to maintain the seal - be sure to block
open the throttle valve as far as possible
during the compression check!
6.7 Label both ends of each wire and hose
before disconnecting it
3261 Jaguar XJ6

5If equipped with an automatic transmission,
disconnect the cooler lines from the radiator
(see illustrations). Disconnect the cooling fan
switch connector (see illustration 4.15).
Place a drip pan to catch the fluid and cap the
fittings. Note:The transmission oil cooler lines
enter the radiator on the left, while the power
steering cooler lines attach on the right side of
the radiator. On 1993 and 1994 models, the
cooler fittings require a spring-lock coupling
tool, normally used on fuel lines or air
conditioning lines.
6Remove the four bolts from the radiator
cowl panel and take off the panel (see
illustration).
7Lift out the radiator. Be aware of dripping
fluids and the sharp fins. Take care not to
damage the radiator fins by contact with other
parts.
8With the radiator removed, it can be
inspected for leaks, damage and internal
blockage. If repairs are necessary, have a
radiator specialist or dealer service department
perform the work, as special techniques are
required. Check the rubber mounting pads on
the bottom of the radiator (see illustration). If
they’re cracked or damaged, get new ones
before refitting the radiator.
9Bugs and dirt can be cleaned from the
radiator with compressed air and a soft brush.
Don’t bend the cooling fins as this is done.
Warning: Wear eye protection.
Refitting
10Refitting is the reverse of the removal
procedure. Be sure the rubber mounts are in
place on the bottom of the radiator.
11After refitting, fill the cooling system with
the proper mixture of antifreeze and water.
Refer to Chapter 1 if necessary.
12Start the engine and check for leaks.
Allow the engine to reach normal operating
temperature, indicated by both radiator hoses
becoming hot. Recheck the coolant level and
add more if required.
13On automatic transmission equipped
models, check and add fluid as needed and
check the power steering fluid level as well.
Expansion tank and coolant
reservoir, removal and refitting
14The expansion tank is located at the top
of the left-hand side inner wing. With the
cooling system drained below the level of the
expansion tank, remove the hoses, the
coolant level probe and the two screws
mounting it to the body (see illustration).
15Wash out and inspect the reservoir for
cracks and chafing. Renew it if damaged.16If the low-coolant level light has been
showing on the instrument panel, even when
the coolant level is correct, disconnect the
sensor’s connector and test it with an
ohmmeter (see illustration). The sensor
should be renewed if the resistance at the
connections is over 150 ohms.
Caution: Using a long-necked funnel to
add coolant can damage the sensor, which
is just below the expansion tank filler neck.
Cooling, heating and air conditioning systems 3•5
3
5.5a At the left side of the radiator,
disconnect the automatic transmission
cooler lines (small arrows) and the lower
radiator hose (larger arrow)5.5b Disconnect the power steering cooler
lines (small arrows) at the right side of the
radiator, and the upper radiator hose
(large arrow)
3261 Jaguar XJ6 5.3 Remove the clamp and the hose going
to the expansion tank
5.6 Remove the bolts (arrowed) and take
off the radiator cowl panel
5.14 The expansion tank is located on the
left inner wing
A Hose to recovery tank (where applicable)
B Hose to radiator
C Hose to thermostat housing
D Hose to water pump housing
E Mounting screws
F Low-coolant-level sensor
5.8 There are rubber mounts (arrowed)
for the radiator and the condenser -
they must be in place when these
components are reinstalled
5.16 The low-coolant-level sensor can be
tested with an ohmmeter - resistance
should be below 150 ohms - gently use a
pair of long-neck pliers to move the sensor
up and down in the tank to get a reading

3261 Jaguar XJ6
4
Chapter 4
Fuel and exhaust systems
Fuel system
Fuel pressure:kPa psi
Ignition ON, engine not running . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 to 300 38 to 44
Engine idling:
Vacuum hose detached from fuel pressure regulator . . . . . . . . . . . 280 to 320 40 to 46
Vacuum hose attached to fuel pressure regulator . . . . . . . . . . . . . 210 to 260 30 to 38
Fuel system hold pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 21
Fuel injector resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 to 3.0 ohms
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Must be set by authorised service department
Torque wrench settingsNm lbf ft
Throttle body mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 14
Fuel rail mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 9 Accelerator cable - removal, refitting and adjustment . . . . . . . . . . . 10
Air cleaner assembly - removal and refitting . . . . . . . . . . . . . . . . . . . 9
Catalytic converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 6
CHECK ENGINE light . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 6
Electronic Fuel Injection (EFI) system - check . . . . . . . . . . . . . . . . . . 12
Electronic Fuel Injection (EFI) system - component check
and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Electronic Fuel Injection (EFI) system - general information . . . . . . . 11
Exhaust manifold - removal and refitting . . . . . . . . . . . See Chapter 2A
Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Exhaust system servicing - general information . . . . . . . . . . . . . . . . 14
Fuel filter renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1Fuel level sender unit - check and renewal . . . . . . . . . . . . . . . . . . . . 5
Fuel lines and fittings - inspection and renewal . . . . . . . . . . . . . . . . 6
Fuel pressure relief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Fuel pump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Fuel pump/fuel pressure - check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Fuel system check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Fuel tank - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Fuel tank cap gasket renewal . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Fuel tank cleaning and repair - general information . . . . . . . . . . . . . 8
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Intake manifold - removal and refitting . . . . . . . . . . . . See Chapter 2A
Underbonnet hose check and renewal . . . . . . . . . . . . . . See Chapter 1
4•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 fuel system consists of a fuel tank, an
electric fuel pump either located externally,
next to the fuel tank (1988 to 1990 models) or
in the fuel tank (1991 to 1994 models), an EFI
fuel pump relay and main relay, an inertia
switch, fuel injectors and fuel rail, an air
cleaner assembly and a throttle body unit.
Multi Point Fuel Injection (MPFI)
system
Multi point fuel injection uses timed
impulses to sequentially inject the fuel directly
into the intake port of each cylinder. Theinjectors are controlled by the Electronic
Control Unit (ECU). The ECU monitors various
engine parameters and delivers the exact
amount of fuel, in the correct sequence, into
the intake ports. The throttle body serves only
to control the amount of air passing into the
system. Because each cylinder is equipped
with an injector mounted immediately
adjacent to the intake valve, much better
control of the fuel/air mixture ratio is possible.
Fuel pump and lines
Fuel is circulated from the fuel tank to the
fuel injection system, and back to the fuel
tank, through a pair of metal lines running
along the underside of the vehicle. On early
models (1988 to 1990), an electric fuel pump
is attached to the chassis next to the fueltank. On later models (1991 to 1994), the fuel
pump and fuel level sender unit are located
inside the fuel tank. A vapour return system
routes all vapours and hot fuel back to the fuel
tank through a separate return line.
The fuel pump will operate as long as the
engine is cranking or running and the ECU is
receiving ignition reference pulses from the
electronic ignition system (see Chapter 5). If
there are no reference pulses, the fuel pump
will shut off after 2 or 3 seconds.Inertia switch
These models are equipped with an inertia
switch that is wired in the circuit between the
fuel pump relay, the ignition switch and the
fuel pump (refer to the wiring diagrams at the
end of Chapter 12). The inertia switch is a

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)

indexed near the bottom, therefore it will be
necessary to turn the module slightly to unlock
it from the rubber holder mounted on the
bottom of the fuel tank.
14Renew the fuel pump module as a single
unit.
15Refitting is the reverse of removal.
5 Fuel level sender unit- check
and renewal
3
Warning: Petrol is highly
flammable, so take precautions
when you work on any part of
the fuel system. See the
Warning in Section 2.
Note:Some 1994 models may be equipped
with faulty fuel level sender units. A tight float
rod bushing may cause the float to stick and
indicate high fuel levels while the tank is
almost empty.
Check
1Before performing any tests on the fuel
level sender unit, completely fill the tank with
fuel.
2Remove the boot liner (see Chapter 12) to
expose the fuel level sender unit access
cover.
3Disconnect the fuel level sender unit
electrical connector located on the accesscover.Note:1991 to 1994 models are
equipped with a fuel pump module and a
sender unit assembly while 1988 and 1989
models are equipped with only the fuel level
sender unit inside the tank.
4Position the ohmmeter probes on the
electrical connector terminals (see
illustration)and check for resistance. Use the
200 ohm scale on the ohmmeter.
5With the fuel tank completely full, the
resistance should be about 18 to 20 ohms.
6Reconnect the electrical connector and
drive it until the tank is nearly empty.
7Check the resistance. The resistance of the
sender unit should be about 190 to 200 ohms.8If the readings are incorrect, renew the
sender unit. Note:The test can also be
performed with the fuel level sender unit
removed from the fuel tank. Using an
ohmmeter, check the resistance of the sender
unit with the swing arm completely down (tank
empty) and with the arm up (tank full) (see
illustration). The resistance should change
steadily from 200 ohms to around 18 ohms.
Renewal
Warning: The fuel level in the
tank must be less than half full
to safely remove the fuel
pump/sender unit assembly from the fuel
Fuel and exhaust systems 4•5
4
5.4 Connect the probes of the ohmmeter
to the fuel level sender unit terminals and
check the resistance of the float assembly5.8 An accurate check of the sender unit
can be made by removing it from the fuel
tank and observing the resistance with the
float down (empty) and then extended (full)
3261 Jaguar XJ6
4.12 Exploded view of the in-
tank fuel pump and the fuel tank
on 1991 to 1994 models

tank. If there is any doubt about the
amount of fuel in the tank, drain the fuel
tank completely before attempting this
procedure (Section 7, paragraph 1).
9Disconnect the cable from the negative
terminal of the battery. Disconnect the fuel level
sender unit/fuel pump electrical connector.
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.
10Using a brass punch, tap on the lock ring
anti-clockwise (see illustration)until the tabs
align with the indentations in the fuel tank.
11Carefully angle the sender unit out of the
opening without damaging the fuel level float
(see illustration).
12Refitting is the reverse of removal.
6 Fuel lines and fittings-
inspection and renewal
2
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:If there is a distinct knocking noise
coming from the dash when the engine is
idling, the fuel feed hose may have hardened,
restricting fuel flow and causing abnormal
sounds. Replace the fuel inlet (feed) hose with
a new one.
Inspection
1Once in a while, you will have to raise the
vehicle to service or renew some component
(an exhaust pipe hanger, for example).
Whenever you work under the vehicle, always
inspect fuel lines and all fittings and
connections for damage or deterioration.
2Check all hoses and pipes for cracks, kinks,
deformation or obstructions.
3Make sure all hoses and pipe clips attach
their associated hoses or pipes securely to
the underside of the vehicle.4Verify all hose clamps attaching rubber
hoses to metal fuel lines or pipes are a tight fit
between the hoses and pipes.
Renewal
5If you must renew any damaged sections,
use hoses or pipes constructed from exactly
the same material as the section you are
replacing. Do not refit substitutes constructed
from inferior or inappropriate material or you
could cause a fuel leak or a fire.
6Always, before detaching or disassembling
any part of the fuel line system, note the
routing of all hoses and pipes and the
orientation of all clamps and clips to assure
that new sections are identically installed.
7Before detaching any part of the fuel
system, be sure to relieve the pressure in the
tank by removing the fuel tank cap, then
relieve the fuel system pressure (Section 2).
Cover the fitting being disconnected with a
rag to absorb any fuel that may leak out.
7 Fuel tank-
removal and refitting
3
Warning: Petrol is extremely
flammable, so take extra
precautions when you work onany part of the fuel system. See the
Warning in Section 2.
1This procedure is much easier to perform if
the fuel tank is empty. Some models may have
a drain plug for this purpose. If for some reason
the drain plug can’t be removed, postpone the
job until the tank is empty or siphon the fuel
into an approved container using a siphoning
kit (available at most motor factors).
Warning: Do not start the
siphoning action by mouth!
2Remove the fuel filler cap to relieve fuel
tank pressure.
3Detach the battery negative cable.
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.
4If the tank is full or nearly full, drain the fuel
into an approved container.
5Raise the vehicle and place it securely on
axle stands.
6Remove the filler neck vent tube clamp (see
illustration)and separate the tube from the
fuel filler neck.
7Remove the fuel filler assembly bolts (see
illustration)and slide the large rubber boot
down the neck of the fuel tank. Note:These
vehicles are susceptible to clogging of the fuel
overflow line. If this happens, excess fuel or
4•6 Fuel and exhaust systems
7.6 Remove the clamp that retains the fuel
filler assembly to the filler neck7.7a Remove bolts (arrowed) that retain the
fuel filler assembly to the body and slide the
assembly down the filler neck of fuel tank
3261 Jaguar XJ6 5.10 Use a brass punch and remove the lock ring by tapping on it
in an anti-clockwise direction
5.11 Lift the fuel level sender unit assembly from the fuel tank at
an angle so as not to damage the float or arm

water in the fuel filler cap recess could flow
into the boot, causing a dangerous condition
and/or an unpleasant mess. To correct this
condition, direct low-pressure compressed air
into the overflow hole (see illustration), which
should be enough to clear any obstruction in
the line.
8Remove the spare tyre and the spare tyre
bracket assembly (see illustration).
9Disconnect the fuel lines, the vapour return
line and the canister vent line (see
illustrations). Note:Be sure to plug the hoses
to prevent leakage and contamination of the
fuel system.Remove the driveline to gain
access to the fuel line connectors next to the
tank (see Chapter 8). Working under the
vehicle, remove the pins using a needle-nose
pliers, turn the connectors slightly to loosen
them from the grommets and pull the fuel lines
out of the tank.10Remove the retaining bolts from the
fuel tank retaining straps (see illustration).
11Pull the fuel tank out into the boot area.Be careful to angle the fuel filler neck away
from the body.
12Remove the tank from the vehicle.
13Refitting is the reverse of removal.
8 Fuel tank cleaning
and repair-
general information
5
1Any repairs to the fuel tank or filler neck
should be carried out by a professional who
has experience in this critical and potentially
dangerous work. Even after cleaning and
flushing of the fuel system, explosive fumes
can remain and ignite during repair of the tank.
2If the fuel tank is removed from the vehicle,
it should not be placed in an area where
sparks or open flames could ignite the fumes
coming out of the tank. Be especially careful
inside garages where a natural petrol-type
appliance is located, because the pilot light
could cause an explosion.
9 Air cleaner assembly-
removal and refitting
1
1Detach the clips and remove the air filter
cover and the filter element (see Chapter 1).
2Remove the bolts and remove the air cleaner
assembly from the engine compartment (see
illustrations).
3Refitting is the reverse of removal.
Fuel and exhaust systems 4•7
4
7.7b Direct low pressure compressed air
into the hole for the overflow line if clogged7.8 Remove the bolts (arrowed) from the
spare tyre bracket and lift out the assembly7.9a Disconnect the flexible fuel lines from
the metal fuel lines
7.9b Disconnect the vapour return line
from the fuel tank7.9c Disconnect the canister purge line
from the fuel tank
7.9d Remove the clips (arrowed) that
retain the fuel lines to the fuel tank using
needle-nose pliers
3261 Jaguar XJ6
7.10 Remove the tank strap bolts
(arrowed) from the body
9.2a Remove the bolts (arrowed) from the
air cleaner assembly9.2b Also, remove the bolt that retains the
air intake duct to the MAF sensor and lift
the assembly from the compartment

7Start the engine and observe the vacuum
gauge. At idle, there should be no vacuum
present. Raise the engine rpm and observe
the vacuum increase. This is a ported vacuum
source and therefore it should only register
vacuum when throttled.
8Check the operation of the EGR control
solenoid. Check for battery voltage to the EGR
control solenoid harness (see illustration). If
battery voltage is not available, check the
harness. Refer to the wiring diagrams at the
end of Chapter 12.
9If battery voltage is available to the EGR
control solenoid, have the EGR system
diagnosed by a dealer service department or
other qualified repair workshop.
EGR valve renewal
10Detach the vacuum hose, disconnect the
fitting that attaches the EGR pipe to the EGR
valve and remove the EGR valve from the
exhaust manifold and check it for sticking and
heavy carbon deposits. If the valve is sticking
or clogged with deposits, clean or renew it.
11Refitting is the reverse of removal.
7 Evaporative Emission
Control (EVAP) system
Note: Some models may have charcoal
canister vent plugs installed in the canister
from the factory. These blanking plugs must
be removed to allow proper pressure and
release within the EVAP system. Check the
charcoal canister for these additional plugs
and remove them. With the blanking plugs
installed, the fuel tank will collapse causing
rough running and hesitation and loss of
power under load.
General description
1This system is designed to trap and store
fuel that evaporates from the fuel tank, throttle
body and intake manifold that would normally
enter the atmosphere in the form of
hydrocarbon (HC) emissions.
2The Evaporative Emission Control (EVAP)
system consists of a charcoal-filled canister,
the lines connecting the canister to the fuel
tank, tank pressure control valve, purgecontrol valve and thermal vacuum valve (TVV)
(see illustration). Note: 1993 and 1994
models have a purge control solenoid that is
controlled by the ECU. This solenoid switches
vacuum to the purge control valve.
3Fuel vapours are transferred from the fuel
tank and throttle body to a canister where
they’re stored when the engine isn’t running.
When the engine is running, the fuel vapours
are purged from the canister by intake airflow
and consumed in the normal combustion
process.Note: The ECU will set a code 89 if
the purge control valve is defective or the
circuit has shorted.
4The fuel tank is equipped with a pressure
control valve. This valve opens and closes
according to the pressure increase and
decrease in the fuel tank.
Check
5Poor idle, stalling and poor driveability can
all be caused by an inoperative pressure relief
valve, split or cracked hoses or hoses
connected to the wrong fittings. Check the
fuel tank filler cap for a damaged or deformed
gasket.
6Evidence of fuel loss or fuel odour can be
caused by liquid fuel leaking from fuel lines, a
cracked or damaged canister, an inoperative
fuel tank control valve, disconnected,
misrouted, kinked, deteriorated or damaged
vapour or control hoses.
7Inspect each hose attached to the canister
for kinks, leaks and cracks along its entire
length. Repair or renew as necessary.
8Look for fuel leaking from the bottom of the
6•10 Emissions and engine control systems
6.8 Check for battery voltage to the EGR
control solenoid
3261 Jaguar XJ6
7.2 Schematic of the
EVAP system

canister. If fuel is leaking, renew the canister
and check the hoses and hose routing.
9Inspect the canister. If it’s cracked or
damaged, renew it.
10Check for a clogged filter or a damaged
pressure relief valve. Using low pressure
compressed air (such as from a tyre pump),
blow into the canister tank pipe. Air should
flow freely from the other pipes. If a problem is
found, renew the canister.
11Check the operation of the thermal
vacuum valve (TVV). With the engine cold and
idling, check for ported vacuum to the
temperature vacuum switch. Vacuum should
be present (see illustration). Now warm the
engine to operating temperature (above
115°F/43°C) and confirm that ported vacuum
passes through the TVV (see illustration).
Renew the valve if the test results are
incorrect.
12Check the operation of the purge control
valve. Apply vacuum to the purge control valve
using a hand-held vacuum pump and observe
that the valve holds vacuum steadily (see
illustration). If the valve holds vacuum and the
valve is opening, it is working properly.
Charcoal canister renewal
13Clearly label, then detach the vacuum
hoses from the canister.
14Remove the mounting clamp bolts (see
illustration), lower the canister with thebracket, disconnect the hoses from the check
valve and remove it from the vehicle.
15Refitting is the reverse of removal.
8 Crankcase ventilation
system
General information
1The crankcase ventilation system reduces
hydrocarbon emissions by scavenging
crankcase vapours. It does this by circulating
fresh air from the air cleaner through the
crankcase, where it mixes with blow-by gases
and is then re-routed through a heating
element to the intake manifold(see
illustration).
2The main components of the crankcase
ventilation system are the control orifice, a
heating element and the vacuum hoses
connecting these components with the engine.
3Piston blow-by gasses are collected from
the crankcase and the camshaft housing
via the oil filler tube. These gasses are fed into
the intake manifold at part throttle through the
part throttle orifice and when the engine is at
full throttle, the gasses are fed through the air
intake elbow.
4To prevent possible icing-up during cold
weather operation, the control orifice and the
hose to the intake system is electronically
heated. The heater element is energised by a
relay signal from the windscreen washer jet
temperature sensor.
Check
5Remove the tubes and elbows that connect
the crankcase ventilation system and inspect
them for obstructions, oil deposits or clogging.
Make sure the ventilation system is free of all
Emissions and engine control systems 6•11
6
7.11a Check for vacuum to the thermal
vacuum valve (TVV)7.11b Check for vacuum from the TVV
before and after the engine has reached
normal operating temperature
7.12 Remove the front spoiler to gain
access to the purge control valve (see
Chapter 11). Apply vacuum to the valve and
make sure the valve holds vacuum7.14 Remove the bolts (arrowed) and lower
the charcoal canister from the wing
8.1 Schematic of the crankcase ventilation system
3261 Jaguar XJ6

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