fuel pressure JAGUAR X308 1998 2.G Repair Manual

All vehicles are fitted with a stainless steel exhaust system which features:
Low back-pressure gas flow. Catalytic converters for mark ets having unleaded fuel. Front muffler common to the left-hand and right-hand engine cylinder banks.
Downpipe Catalytic Converter Assembly

Fuel System - General Inform
ation - Fuel System
Description an
d Operation

The fuel tank is mounted across the vehicle behind the passenger compartment bulkhead.
Fuel is drawn by the fuel pump from the tank and then supplied to the two fuel rails, via a filter.
Fuel injectors are installed in the fuel ra ils on each side of the intake manifold.
The amount of fuel injected into th e engine is controlled by the ECM.
A cross-over pipe connects the two fuel ra ils together at the front of the manifold.
A test valve in the cross-over pipe allo ws the fuel rail to be pressurized and de-pressurized during the servicing and
troubleshooting procedures.
A pressure regulator on the rear of the right fuel rail controls the pressure in the fuel rails.
A return line directs excess fuel from the pressure regulator back to the fuel tank.
Operation and service procedures
The fuel injector
s, rails, pres
sure regulator and, wher e fitted, supercharger are described in greater detail in Section 303-04
together with servicing procedures.
The fuel tank, pump, fuel level senders and fuel lines are similarly covered in Section 310-01.

Fuel System - General Information - Fuel System Pre
ssure Check
Gen
eral Procedures
WARNING: Working on the fuel system re sults in fuel and fuel vapor being present in the atmosphere. Fuel vapor is
extremely flammable, hence great care must be taken whilst working on the fuel system. Adhere strictly to the following
precautions:
D
o not smoke in the work area
Di

splay
NO SMOKING signs around the work area
D
isconnect the battery before
working on the fuel system
Av
oid sparks
Make sure sui

table fire ex
tinguishers are at hand
Make sure absor
bent material is at
hand to soak up any spillage
Make sure the work area is
well ventilated
M

ake sure that the gauge is correctly conn
ected, and that all connections are secure BEFORE starting the engine
DO N
OT
disconnect the gauge from the schrader valve while the engine is running
Make su
re the schrader valve reseals once the gauge is disconnected
• NOTE: Depending on the design of the ga uge set, there may be a drain valve and tube. Make sure this valve is closed, and
the drain tube placed in a suitable container BEFORE connecting the gauge to the schrader valve.


1. Make sure the vehi
cle is in
Park for vehicles with automatic
transmission, Neutral for vehicles with manual transmission.
2. Apply the parking brake.
3. Place suitable absorbent material around the schrader valve to
absorb any spillage when connecting the gauge set.
4. Remove the protective cap from the schrader valve.
5. Connect the gauge, using adaptors if required.
6. Remove the absorbent material and dispose of safely.
7. Disconnect and plug the vacuum hose from the pressure
regulator.
8. Start the engine and record the fuel pressure reading.
As a gui
de, the fuel pressu
re should be approximately 3.0
bar (44.1 psi) with the regulator disconnected.
9. With the engine still running, reconnect the vacuum hose to
the pressure regulator an d record the reading.
Th
e pressure should dr
op to approximately 2.6 bar (38
psi) when the vacuum hose is reconnected.
10. Switch off the engine.
11. Place more absorbent material around the schrader valve.
12. Where fitted, open the drain valve and allow the fuel from the
gauge and line to flow into the container to depressurize the
system.
13. Disconnect and remove the gauge set and any adaptors.
14. Clean up any fuel which may have been spilt and remove the
absorbent material. Dispose of safely.
15. Refit and secure the protective cap to the schrader valve.
16. Reconnect the fuel pressure regulator vacuum hose.
17. Start the engine and make sure there are no leaks.

Fuel System - General Information - Fuel System Pressure Rele
ase
Gen
e
ral Procedures


S p
ecial Tool(s)

Tes
t
Equipment - Fuel Pressure Relief
310-058 (TE 7635A or JD 209)
1. WARNING: BEFORE PROCEEDING, IT IS ESSENTIAL THAT
THE WARNING NOTES GIVEN IN SECTION 100-00 (UNDER THE
HEADING 'SAFETY PRECAUTIONS') ARE READ AND
UNDERSTOOD.
Open engine compartment and fi t paintwork protection sheets.
2. Carefull
y remove left
hand engine cover, taking care not to
damage the plasti c fixings or the rubber inserts.

3. WA
RNING: MAKE SURE EQUIPMENT BLEED / DRAIN
VALVE IS CLOSED.
• NOTE: Place a cloth under the valve to collect any spillage.
Depressurize fuel system.
Make sure ignition i s
switched off.
R
e
move cap from Schrader valve.
Pla
c
e a closed container, su
itable for collecting fuel,
adjacent to vehicle.
R e
move lid from container.
Conne
ct
fuel injection pressu
re test equipment 310-058
(TE 7635A or other suitable type).
Insert drain / bleed tu be i
nto fuel container.
R
e
ad and follow manufacturer's instructions to
depressurize fuel system.
4. Store drained f u
el safely and make
sure container lid is closed
securely.
5. Remove equipment and discard cloth from beneath the valve.
6. Install valve cap.
7. Install left hand engine cover.

Fuel Tank and Lines - Fuel Tank and Li
nes
Description an
d Operation

Fuel Tank

Parts List
The steel fuel tank is located inside the trunk and mounted across the vehicle behind the passenger compartment bulkhead.
The fuel tank is held in posi tion by two retaining straps fi tted to body-mounted brackets.
The fuel tank has an integral non-adjustable fill er pipe and integral breather and vapor pipework.
A single fuel pump is mounted inside the tank on vehicles with normally aspirated engines. For vehicles with supercharged
engines, two pumps are fitted in the tank. Fuel is drawn by the pump(s) from the fuel tank and supplied via the fuel lines
and 70 micron filter to the fuel rails.
The fuel lines run from front-to-rear down the vehicle's left-hand-side.
Ite
m
Part
Number
Descr
iption
1—Fu

el filler latch box
2—Pressure reli

ef pipe, ORVR
(shown) / tank breather pipe on non-ORVR systems
3—Tank grounding
cable
4—Evaporative flan
ge assembly
(ORVR type shown)
5—Trunk elec
trical harne
ss (part of)
6—Fue
l
level sensor
flange/connector
7—Fu
el tank retaining straps
8—F
u
el tank retaining stra
ps adjustable clamps
9—Fu
el tank retaining straps lower brackets
10—Tank vapor outlet pipe to un
derflo
or pipe quick-fit connector
11—F
u
el filler latch bo
x water drain pipe

Filler Cap and P
ipe
The fuel
filler cap with bayonet-type fixi
ng is located beneath a remote-release sp ring-latched lid on the rear saddle panel
on the left-hand-side of the vehicle.
Fuel Pum
p
The fu
el pump(s) is energized by an ECM co
ntrolled relay. Fuel is drawn by this pu mp and supplied to the fuel injectors via
the fuel line, filter and fuel rails.
Servicing of the fuel pump re quires fuel tank removal.
Ev
aporative Loss Flange Assembly
The evaporative-loss flan
ge asse
mbly is mounted centrally on top of the tank. The flange assembly consists of a removeable
steel cap which mounts the evaporative emissions system vapor outlet valves and, if applicable, a pressure sensor. The
external electrical supply to th e fuel pump(s) is also made via a connector on the flange.
The flange assembly is fixed to the tank by a locking ring which is turned usin g special tool JD-174. A seal is fitted between
the flange assembly and the tank. Three di fferent flange assemblies are applicable according to the evaporative emission
system fitted to the vehicle. The fl ange size and fixing are identical fo r the three systems, as described.
Removal of the evaporative flange assembly is necessary to gain access to th e fuel pump(s) and other internal components.
To remove the evaporative fl ange assembly the fuel tank must first be removed.
The evaporative flange variant assemblies are described, together with service information, in Section 303-13.
Fuel R
eturn
Excess fuel
is directed back to
the fuel tank via a return line.
Fuel Pum
p Relay
The
fuel pump relay,
under control of the ECM, switches power to the fuel pump motor.
I
nertia Fuel Shutoff (IFS) Switch
The IF
S switch is located in the right-hand
side footwell behind the footboard carpet . When activated the switch isolates the
ignition system and fuel pump, releases any locked doors and disables unnecessary electrical systems. The system can be
reset by pressing down the flexible cover on the top of the switch.
• NOTE: The doors will not unlock if the IFS switch is tripped when the ignition switch is in position '0'.

10
.
Disconnect the fuel feed and return pipes from the fuel tank
F
it special tool JD-203 around
the pipe as shown. Press
the tool in between the fuel pipe and tank connector to
release the quick-fit tangs. While holding the tool firmly in,
pull out the fuel pipe.
Repeat
for the second pipe.
Plu

g the tank outlet connectors and the fuel pipes.

11
.
From the underside of the vehicl e, release the fuel filler latch
box drain pipe from the clip on the spare wheel well.

12
.
Disconnect and reposition the tr unk harness if it is routed
between the filler tube and the ta nk breather or pressure relief
pipe.
1. Disconnect the lefthand re ar lamp harness connector.
2. Disconnect the fuel flap lock actuator connector.
3. If fitted, disconnect the lefthand side marker lamp
connector and harness fro m the underside of the
vehicle. Withdraw the marker lamp harness and
grommet through the trunk floor access hole.
4. Release the harness securi ng clip from the mounting
bracket.
Wi
thdraw the trunk harness from between the filler tube
and the breather pipe or pressure relief pipe.
13. Disconnect the tank harness connections.

1.
If fitted, disconnect the
wiring to the accelerometer.
2. Disconnect the wiring to the fuel level sensor harness.

3.
Disc
onnect the wiring to
the fuel pump connector.
4. If fitted, disconnect the wi ring to the pressure sensor
connector.

14 . R
emove fuel filler
latch box drain pipe.
1. Cut and remove the ratche t strap securing the drain
pipe to the filler tube.
2. Disconnect the drain pipe from the fuel filler latch box.
3. Pull the drain pipe th rough the body grommet and
remove.

15 . Di
sconnect the vapo
ur outlet pipe.
Relea
se the quick-fit coupling .
Plu
g
the vapour pipes.

16 . D
isconnect the fuel filler la
tch box from the filler tube.
Open t
he fuel filler flap
and remove the filler cap.
1. Remove the spring ring se curing the fuel filler latch
box to the filler neck.
2. Pull the fuel filler latch box free of the filler tube.
17. Detach the tank retaining straps.
Tape or tie the two reta i
ning straps/brackets to the rear
scuttle to allow tank removal.

pipe.
3
. Tie the drain pipe to th
e filler tube using a ratchet
strap. Trim strap.

10
.
Reconnect the trunk harness connections.
1. If fitted, connect the wi ring to the accelerometer.
2. Connect the wiring to the fuel level sensor harness.
3. Connect the wiring to th e fuel pump connector.
4. If fitted, connect the wiring to the pressure sensor connector.

11
.
Reconnect the lefthand side trunk harness if it has been
necessary to move it for access. Route the harness behind both
the filler tube and breather or pressure relief pipe.
1. Fit the harness securing cl ip to the mounting bracket.
2. Connect the fuel flap lock actuator connector.
3. Connect the lefthand rear lamp harness connector.
4. If applicable, feed the side marker lamp harness through the access hole in the floor and reseat the
sealing grommet.
On
the underside of the vehicl
e, fit the side marker lamp
connector and fix the harness to the securing clips.

12
.
On the underside of the vehicle, fit the drain pipe to the
securing clip.
13. On the underside of the vehicle, reconnect the fuel feed and
return pipes.
R
emove the plugs from the tank
and fuel feed and return

Instrument Cluster - Instrument Cluster
Description and Operation
ItemDescription
1Variable Power Steering
2Coolant Level
3Fuel Level
4Oil Pressure
5Lamp Dimmer
6Driver's Switchpack
7Generator (Charge Warning Lamp)
8Catalyst Overheat
9Instrument Cluster
10Climate Control (Signal to Module)
11ICE Head Unit