Jaguar XJ (X350). Manual — part 673

Fuel Charging and Controls

Principle of operation

Common rail diesel

The 2.7L fuel injection system is a common-rail design, running at the high-pressures (up to 1,650 bar

or 23,930 lb/in²) typical of such systems.

The fuel is drawn from the fuel tank by an electric fuel pump module and delivered to the transfer

pump side of a fuel injection pump driven by the engine. For additional information on the fuel

injection pump,

Fuel Charging and Controls

The fuel volume control valve (FVCV) regulates the amount of fuel supplied to the high-pressure side

of the fuel injection pump, while the fuel pressure control valve (FPCV) regulates the pressure.

The high-pressure fuel is delivered to the fuel rail where it is stored, ready for use by the fuel

injectors.

The fuel injectors are Piezo type, and are controlled by the engine control module (ECM) from inputs

from the engine management sensors.

The fuel injectors operate in stages, giving a pilot injection before the main injection to reduce

detonation noise and help improve the efficiency of the engine.

For additional information,

Fuel Charging and Controls

Overview

There are changes to the engine management system (EMS) for 2006 my, the most obvious of which

will be the change to 7-digit diagnostic trouble codes (DTCs) from the familiar 5-digit.

Refer to the DTC index in this section for guidance on how to use these codes with the Jaguar

approved diagnostic system or a scan tool.

Inspection and Verification

WARNING: Do NOT carry out any work on the fuel system with the engine running. The fuel

pressure within the system can be as high as 1650 bar (23,930 lb/in²). Failure to follow this

instruction may result in personal injury.

WARNING: Eye protection must be worn at all times when working on or near any fuel

related components. Failure to follow this instruction may result in personal injury.

WARNING: This procedure involves fuel handling. Be prepared for fuel spillage at all times

and always observe fuel handling precautions. Failure to follow this instruction may result in

personal injury.

WARNING: After carrying out repairs, the fuel system must be checked visually for leaks.

This should be done after the engine has been run, but with the engine switched OFF. Failure to

follow this instruction may result in personal injury.

WARNING: If taken internally, DO NOT induce vomiting. Seek immediate medical attention.

Failure to follow this instruction may result in personal injury.

WARNING: If fuel contacts the eyes, flush the eyes with cold water or eyewash solution and

seek medical attention. Failure to follow this instruction may result in personal injury.

WARNING: Wash hands thoroughly after handling, as prolonged contact may cause

irritation. Should irritation develop, seek medical attention. Failure to follow this instruction may

result in personal injury.

CAUTION: Before disconnecting any part of the system, it is imperative that all dust, dirt

and debris is removed from around components to prevent ingress of foreign matter into the fuel

system. Failure to follow this instruction may result in damage to the vehicle.

CAUTION: The fuel pipes between the injectors and the rail must be discarded after each

use, and new pipes installed. Failure to follow this instruction may result in damage to the vehicle.

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CAUTION: It is essential that absolute cleanliness is observed when working with these

components. Always install blanking plugs to any open orifices or lines. Failure to follow this

instruction may result in damage to the vehicle.

CAUTION: Make sure that the workshop area in which the vehicle is being worked on is as

clean and dust-free as possible. Areas in which work on clutches, brakes or where welding or

machining are carried out are not suitable in view of the risk of contamination to the fuel system.

Failure to follow this instruction may result in damage to the vehicle.

CAUTION: Make sure that any protective clothing worn is clean and made from lint-free

non-flocking material. Failure to follow this instruction may result in damage to the vehicle.

CAUTION: Make sure that any protective gloves worn are new and are of the non-powdered

latex type. Failure to follow this instruction may result in damage to the vehicle.

CAUTION: Make sure that clean, non-plated tools are used. Clean tools using a new brush

that will not lose it's bristles and fresh cleaning fluid prior to starting work on the vehicle. Failure

to follow this instruction may result in damage to the vehicle.

CAUTION: Use a steel-topped work bench and cover it with clean, lint-free, non-flocking

material. Failure to follow this instruction may result in damage to the vehicle.

CAUTION: When probing connectors to take measurements in the course of the pinpoint

tests, use the adaptor kit, part number 3548-1358-00. Failure to follow this instruction may result

in damage to the vehicle.

NOTE:

This section contains references to Parameter Identifiers (PIDs). Where the Jaguar approved

diagnostic system is not available, a scantool may be used to access these PIDs, all of which give

information, and some of which can be used to both read information and to activate

components. The format of the information may vary, depending on the tool used.

NOTE:

When performing voltage or resistance tests, always use a digital multimeter (DMM) accurate to

3 decimal places, and with an up-to-date calibration certificate. When testing resistance, always

take the resistance of the DMM leads into account.

NOTE:

Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.

NOTE:

If diagnostic trouble codes (DTCs) are recorded and the symptom is not present when

performing the pinpoint tests, an intermittent concern may be the cause. Always check for loose

connections and corroded terminals.

1 . Verify the customer concern.

2 . Confirm which, if any, warning lights and/or messages were displayed on the instrument cluster.

3 . Visually inspect for obvious signs of mechanical or electrical damage.

Mechanical

Electrical

Fuel level

Contaminated fuel

Fuel supply line(s)

Fuel return line(s)

High-pressure fuel supply line(s)

Fuel tank filler pipe

Glow plug indicator

Inertia fuel shutoff (IFS) switch

Fuel pump module

Sensor(s)

Engine control module (ECM)

Fuel volume control valve (FVCV)

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