1994 JAGUAR XJ6 Workshop Manual

ii

Fig. 1 Fuel System Layout
119 L62
The above schematic illustration (Fig. I), shows the part and component layout of the fuel system and is to be read with
the table on Page 2.
X300 VSM 1 Issue 1 August 1994

+ 17.15.13
17.50.30
Component / parts
Fuel filler assembly
Fuel tank
Fuel pumps
Fuel
pump filter
Fuel feed line
Fuel filter
Fuel feed line
Fuel rail
Fuel injectors
Fuel regulator valve
Fuel return line
Emission vent line
Tank pressure control
(Rochester) valve
Emission vent line
Primary carbon canister
Emission vent line
Purge valve
Emission vent line
Location Number
Rear deck area
1
Behind rear bulkhead 2
Inside fuel tank 3
Inside fuel tank 4
Fuel
pump to fuel filter 5
Above rear axle assembly 6
Fuel filter to fuel rail 7
Inlet manifold
8
Inlet manifold /fuel rail 9
Mounted on the fuel rail 10
Fuel regulator to fuel tank 11
Fuel tank to tank pressure 12
control (Rochester) valve
Connected between
emission vent lines as
shown on schematic 13
Rochester valve to primary 14
carbon canister
Left side
of vehicle, in 15
front of the rear axle
Primary carbon canister to 16
purge valve
Below the left head lamp 17
module
Primary carbon canister
to at-
mosphere
18
0
0
0
Issue 1 August 1994 2 X300 VSM

striker and the fuel cap stowage magnet.
The fuel bowl, retained around the filler neck by a clip, containing a drain tube filter located
overthe mating drain tube,
is rubber moulded onto a steel armature and fitted to the BIW decking panel. by five M5 nuts.
The fuel lid latching assembly fitted to the metal armature of the fuel bowl by an M5 nut, includes the locking pin and
the operating actuator.
The actuator operates from the central locking system driven by the Security and Locking Control Module (SLCM).
The fuel tank, mounted across the vehicle behind the passenger compartment rear bulkhead, is held in position by two
retaining straps, tightened by two M5 fixing arrangements.
VI2 engined vehicles are equipped with two fuel pumps located inside the tank. They are regenerative turbine pumps
supplied by Nippon Denso. Nominal operating pressure is 3 bar above the manifold depression and pump delivery
is 90 litres/hour minimum at 13.2 volts, 3 bar outlet pressure. The pump draws a nominal current of 7 amperes at 13 volts, 3 bar outlet pressure, ambient temperatures. Built in to the pump assembly is a over-pressure relief valve which
blows at 4.5 - 8.5 bar.
Fuel is drawn by the pumps from the fuel tank and is then supplied to the fuel rail via a
70 micron filter and the fuel
feed line connected in series by fuel filter.
The amount of fuel being injected into the engine is controlled by the fuel injectors combined with the engine control
module (ECM).
Any excessive fuel flowing through the system, is returned to thefuel tankvia the fuel regulator valve mounted on the
fuel rail, the fuel return line and the check valve also located inside the tank.
The two filters prevent contaminants from entering the fuel rail and possible damage to the fuel injectors, the engine,
the pump and underfloor filter.
The second fuel pump is controlled by the engine control module
(ECM) and works of a mapped fuel map. The pumps
'switch on' time depends on the fuel requirement which is depending on the engine load.
The fuel lines are made up of an assembly, combining steel underfloor pipes and flexible conductive anti
-permeation
tubing. In order to perform speedy remove and refit operations, the underfloor steel lines are linked through the engine
bay bulkhead to theflexibletubing, leading to the fuel rail and the fuel regulator by using positive sealing, quick
fit type
connectors. The same type connectors, are used to connect the fuel feed and return line to the fuel tank.
Connectors used inside the engine bay, are of different sizes to correspond with the difference in pipe diameter, where
- as the connectors for the feed and return lines at the fuel tank are the same size.
Except for the return line connector at the fuel tank, two release tools, one for each size of connector, are required to
release all remaining connectors.
Fuel, Emission Control & Engine Management (V12)
5.2.2 GENERAL DESCRIPTION
WARNING: WORKING ON THE FUEL SYSTEM RESULTS IN FUEL AND FUEL VAPOUR BEING PRESENT IN THE AT- MOSPHERE. FUEL VAPOUR IS EXTREMELY FLAMMABLE, HENCE GREAT CARE MUST BE TAKEN WHILST
WORKING ON THE FUEL SYSTEM. ADHERE STRICTLY TO THE FOLLOWING PRECAUTIONS:
PO NOT SMOKF, IN THE WORK AREA.
DISPLAY 'NO SMOKING
' SIGNS AROUND THE AREA.
ENSURE THAT A
CO2 FIRE EXTINGUISHER IS CLOSE AT HAND.
ENSURE THAT DRY SAND
IS AVAILABLE TO SOAK UP ANY FUEL SPILLAGE.
EMPTY FUEL USING SUITABLE FIRE PROOF EQUIPMENT INTO AN AUTHORIZED EXPLOSION PROOF
CONTAINER.
DO NOT EMPTY FUEL INTO A PIT.
ENSURE THAT WORKING AREA IS WELL VENTILATED.
ENSURE THAT ANY WORK ON THE FUEL SYSTEM
IS ONLY CARRIED OUT BY EXPERIENCED AND WELL
QUALIFIED MAINTENANCE PERSONNEL.
The fuel filler assembly, supplied complete with serviceable lid, hinge and hinge spring, is fixed to the Body-in-White (BIW) decking panel by two M5 nuts. Additional parts of the assembly comprise a adjustable rubber buffer, a snap-in
X300 VSM 3 Issue 1 August 1994

Fuel, Emission Control 8t Engine Management (V12)
The connectors are released by pushing the tool in to the female half ofthe connector and at the same time disengaging
the latches.
Viton hosing surrounds the tubing, thus preventing any po
- tential damage from fire and other matters.
The conductive anti
-permeation tubing does not return to
its original shape after being deformed. Therefore do not
clamp (eg. for sealing purposes prior to disconnection of
tubes) as this damages the fuel pipes.
The evaporative
loss control system, prevents unprocessed
vapour emitted from the fuel tank from entering the atmos- phere.
The tank pressure control (Rochester) valve is installed be
- tween the fuel tank and the carbon canister. lt is normally
closed, but open during engine operation, venting the va- pours from the fuel tank to the carbon canister.
The purge valve is controlled by the engine control module
(ECM) and is linked to the carbon canister.
Fig.
1 Quick-fit Connector and Release Tool
X300 VSM Issue 1 August 1994 4

Fig. 1

Fuel, Emission Control & Engine Management (V12)
9
Fig. 1
Disconnect vacuum hose (1 Fig.1) from cruise control actuator (2 Fig.1).
. Disconnect vacuum hose (3 Fig.1) from fuel pressure regulator.
Disconnect throttle control rods from throttle pulley assembly ball pins (4 Fig.1).
. Reposition throttle control rods to inner wings.
. Disconnect cruise control rod from throttle pulley assembly ball pin (5 Fig.1).
. Undo and remove bolts securing fuel rail.
. Reposition cruise control rod below throttle pulley assembly.
. Remove cruise control actuator / bracket assembly and fixings (6 Fig.1).
. Disconnect injector harness plugs (7 Fig.1).
Disconnect throttle potentiometer multi-plug (8 Fig. 1)
. Remove throttle pulley bracket assembly and fixings (9 Fig.1)
. Remove injector harness plastic clips (IO Fig.1) from fuel rail.
. Remove fuel rail / injector assembly (1 1 Fig.1).
Issue 1 August 1994 6 X300 VSM

Fuel, Em i ssion Control & Engine
Management
J19 L76
Fig. 1
Remove injector to fuel rail retaining clips (1 Fig.1).
. Remove injector (2 Fig.1).
Remove fuel regulator retaining plate and fixings (3 Fig.1).
. Remove fuel regulator (4 Fig. 1 ).
. Remove and discard ‘0’ ring seals.
Refit in the reverse order of the removal procedure.
X300 VSM 7 Issue 1 August 1994