fuel JAGUAR XJ6 1997 2.G Owner's Manual

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

special electrical device that provides circuit
protection by switching off the ignition and
fuel pump upon impact in the event of vehicle
collision. Later Jaguar models are equipped
with an additional specialised inertia switch.
This later device switches OFF all ignition fed
circuits, locks the fuel filler cap, locks the boot
(only if doors are locked) and unlocks the
doors if they are locked during the accident.
All these functions are directed by the inertia
switch. The inertia switch is located behind
the left kick panel. Refer to Chapter 12 for
more information.
Exhaust system
The exhaust system includes an exhaust
manifold equipped with an exhaust oxygen
sensor, a catalytic converter, an exhaust pipe,
and a silencer.
The catalytic converter is an emission
control device added to the exhaust system to
reduce pollutants. A single-bed converter is
used in combination with a three-way
(reduction) catalyst. See Chapter 6 for more
information regarding the catalytic converter.
2 Fuel pressure relief
1
Warning: Petrol is extremely
flammable, so take extra
precautions when you work on
any part of the fuel system.
Don’t smoke or allow open flames or bare
light bulbs near the work area, and don’t
work in a garage where a natural gas-type
appliance (such as a water heater or a
clothes dryer) with a pilot light is present.
Since petrol is carcinogenic, wear latex
gloves when there’s a possibility of being
exposed to fuel, and, if you spill any fuel on
your skin, rinse it off immediately with soap
and water. Mop up any spills immediately
and do not store fuel-soaked rags wherethey could ignite. The fuel system is under
constant pressure, so, if any fuel lines are
to be disconnected, the fuel pressure in
the system must be relieved first. When
you perform any kind of work on the fuel
system, wear safety glasses and have a
Class B type fire extinguisher on hand.
1Before servicing any fuel system
component, you must relieve the fuel pressure
to minimise the risk of fire or personal injury.
2Remove the fuel filler cap - this will relieve
any pressure built up in the tank.
3Remove the fuel pump relay from the main
relay panel (see illustrations). Note:These
models are equipped with a fuel pump relay
that is located in various areas of the vehicle
depending on the year. On 1988 and 1989
models, the fuel pump relay is under the
glovebox. On 1990 to 1992 models, the fuel
pump relay is in the engine compartment on
the left side, attached to the brake pedal
hanger. On 1993 models, the fuel pump relay
is in the boot. On 1994 models, it’s in the
engine compartment on the right side of the
bulkhead. Refer to the relay location charts in
Chapter 12 for additional information.
4Start the engine and wait for the engine to
stall, then turn the ignition key to Off.
Disconnect the cable from the negativeterminal of the battery before beginning any
work on the fuel 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.
5The fuel system is now depressurised.
Note:Place a rag around the fuel line before
removing any hose clamp or fitting to prevent
any residual fuel from spilling onto the engine.
3 Fuel pump/fuel pressure-
check
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: To perform the fuel pressure test, you
will need to obtain a fuel pressure gauge and
adapter set (fuel line fittings).
Note: 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.
Preliminary inspection
1Should the fuel system fail to deliver the
proper amount of fuel, or any fuel at all,
inspect it as follows. Remove the fuel filler
cap. Have an assistant turn the ignition key to
the ON position (engine not running) while you
listen at the fuel filler opening. You should
hear a whirring sound that lasts for a couple of
seconds. On 1988 to 1990 models, listen
behind the left rear wheel (external fuel pump)
for the fuel pump sound.
2If you don’t hear anything, check the fuel
pump relay (see illustration 2.3a, b or c)and
4•2 Fuel and exhaust systems
2.3c On 1992 models, the fuel pump relay
is located in the left rear corner of the
engine compartment
3261 Jaguar XJ6 2.3a Relay locations on a 1988 model
2.3b Relay locations on a 1989 model

circuit. If all circuits are intact and not
damaged, check the inertia switch. Note: The
inertia switch is a special device that shuts
down power to the ignition and the fuel pump
in the event of an accident. See Chapter 12 for
checking and resetting procedures for the
inertia switch.
3Remove the relay and check for battery
voltage to the fuel pump relay connector (see
illustration). If there is battery voltage
present, check the relay for proper operation.
Refer to the relay checking procedure in
Chapter 12. Note:If battery voltage is not
available, check for battery voltage to the main
relay(see illustration). Refer to the relay
location diagrams in Chapter 12. The main
relay, which is located next to the fuel pump
relay, supplies voltage to the fuel pump and
ignition system.
4If battery voltage is present, check for
battery voltage directly at the fuel pump
electrical connector (see illustrations), within
two seconds of the ignition key being turned
On. If there is no voltage, check the fuel pump
circuit. If there is voltage present, renew the
pump (see Section 4). Note:It will be
necessary to raise the vehicle and support it
securely on axle stands to gain access to the
fuel pump electrical connectors. Have an
assistant operate the ignition key and be sure
to block the front wheels to avoid any
movement of the vehicle.
Operating pressure check
5Relieve the fuel system pressure (see
Section 2). Detach the cable from the negative
battery terminal.
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.
6Detach the fuel line from the fuel rail and
connect a fuel pressure gauge(see
illustrations)between the fuel pulsationdamper and the fuel rail. Tighten the hose
clamps securely.
7Attach the cable to the negative battery
terminal. Start the engine.
8Note the fuel pressure and compare it with
the pressure listed in this Chapter’s
Specifications.
9Disconnect the vacuum hose from the fuelpressure regulator and hook up a hand-held
vacuum pump (see illustration)to the port on
the fuel pressure regulator.
10Read the fuel pressure gauge with vacuum
applied to the pressure regulator and also with
no vacuum applied. The fuel pressure should
decrease as vacuum increases (and increase
as vacuum decreases).
Fuel and exhaust systems 4•3
4
3261 Jaguar XJ6 3.3a Checking for battery voltage at the fuel pump relay
connector ( 1989 model)
3.3b Checking for battery voltage to the main relay (1989 model)
3.6a Remove the fuel line from the fuel
pulsation damper . . .
3.4b Check for battery voltage to the
fuel pump on the harness connector near
the fuel tank on models with in-tank
fuel pumps3.4a Remove the rubber boot from the fuel
pump electrical connector and check for
voltage while an assistant turns the
ignition key (1989 model shown)
3.6b . . . then refit the fuel pressure gauge
between the fuel rail and the fuel pressure
damper using a T-fitting

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

10 Accelerator cable- removal,
refitting and adjustment
3
Removal
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.
2Loosen the locknut on the threaded portion
of the throttle cable at the throttle body (see
illustration).
3Rotate the throttle lever, then slip the
throttle cable end out of the slot in the lever
(see illustration).
4Detach the throttle cable from the
accelerator pedal (see illustration).
5From inside the vehicle, pull the cable
through the bulkhead.
Refitting and adjustment
6Refitting is the reverse of removal.
7To adjust the cable, fully depress the
accelerator pedal and check that the throttle
is fully opened.
8If not fully opened, loosen the locknuts,
depress accelerator pedal and adjust the
cable until the throttle is fully open.
9Tighten the locknuts and recheck the
adjustment. Make sure the throttle closes fully
when the pedal is released (see illustration).
10After the cable is adjusted, check the
adjustment of the bellcrank. Use a small
clamp and a straight rod or stiff wire (coat
hanger) and attach it to the brake master
cylinder in such a way that the tip acts as a
pointer. Align the pointer with “A” (automatic
transmission) or “M” (manual transmission) on
the bellcrank (see illustration),depending on
what type of transmission is installed in the
vehicle.
11Slowly rotate the bellcrank until it reaches
the throttle stop (wide open throttle) andcheck to make sure the pointer aligns with the
notch in the bellcrank (see illustration).
12If necessary, adjust the position of
the throttle stop using a spanner and turn the
throttle stop screw until the bellcrank reaches
the correct position. Lock the throttle stop
screw in place.
4•8 Fuel and exhaust systems
3261 Jaguar XJ6 10.4 Remove circlip (arrowed) and separate cable from the
accelerator pedal by pulling the pin from the pedal assembly
10.2 Loosen the locknuts on the accelerator cable10.3 Rotate the bellcrank and remove the cable end from the slot
10.9 Make sure the throttle closes completely and there is a
slight amount of flex in the cable
10.10 Attach a strong wire (coat hanger)
to the master cylinder using a clamp and
align it with the notch on the bellcrank

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