Page 1697 of 2305
OPERATION - LOW PRESSURE PUMP
When the ignition switch is on, fused battery posi-
tive voltage is supplied to the electric lift pump,
which will run for 20±30 seconds and then stop. If
the engine is cranked, the pump will begin running
immediately supplying fuel through fuel filter and
onto the high pressure pump. The lift pump and low
pressure fuel circuit operate at a pressure between
3.8 -5.5 bar (55 - 80 psi.).
Fig. 7 PRODUCING HIGH PRESSURE
1 - FUEL SUPPLY TO PUMP 6 - PISTON
2 - VALVE 7 - PISTON SPRING
3 - VALVE SPRING 8 - CAM
4 - CHECK BALL 9 - ECCENTRIC SHAFT
5 - HIGH PRESSURE PASSAGE 10 - CIRCULAR PASSAGE
14 - 16 FUEL DELIVERYVA
Page 1698 of 2305

REMOVAL - HIGH PRESSURE PUMP
(Refer to 14 - FUEL SYSTEM - WARNING)
(1) Disconnect negative battery cable.
(2) Remove viscous fan clutch (Refer to 7 - COOL-
ING/ENGINE/FAN DRIVE VISCOUS CLUTCH -
REMOVAL).
(3) Unplug electrical connectors at high pressure
pump.
CAUTION: DO NOT slacken the threaded connec-
tion. Use a wrench to counterhold at the threaded
connection when loosening and tightening the
union nut. DO NOT EXCEED tightening torque.
CAUTION: DO NOT crimp or bend fuel line. Capture
all fluids that flow out of connections.
(4) Disconnect the high pressure line at high pres-
sure pump (Fig. 8).
(5) Detach fuel supply and return flow line at high
pressure pump using special tool #9539 (Fig. 8).
NOTE: Care must be taken not to drop the high
pressure pump drive when removing pump. Inspect
the pump drive for wear. If wear is present replace
the drive and gear.(6) Remove bolts attaching high pressure pump
and remove pump (Fig. 8).
INSTALLATION - HIGH PRESSURE PUMP
(Refer to 14 - FUEL SYSTEM - WARNING)
CAUTION: Clean sealing surfaces with appropriate
solvents and replace all seals.
NOTE: Inspect then attach high pressure pump
drive if pump is being replaced. If wear is present at
drive, replace drive and gear.
(1) Position and secure the high pressure pump to
cylinder head (Fig. 9). Tighten bolts to 14 N´m (124
lbs. in.).
CAUTION: NEVER slacken the thread connection.
Use a wrench to counterhold at threaded connec-
tion when slackening and tightening torque in order
to avoid also slackening the threaded connection
the next time.
Fig. 8 HIGH PRESSURE FUEL PUMP
1 - INTERMEDIATE GEAR
2 - HIGH PRESSURE PUMP
3 - SEALING RING
4 - DRIVER
5 - HIGH PRESSURE LINE
6 - FUEL SUPPLY LINE
7 - FUEL RETURN LINE
8 - BOLTS
9 - FUEL QUANTITY CONTROL VALVE
10 - FUEL TEMPERATURE SENSOR
Fig. 9 HIGH PRESSURE FUEL PUMP
1 - INTERMEDIATE GEAR
2 - HIGH PRESSURE PUMP
3 - SEALING RING
4 - DRIVER
5 - HIGH PRESSURE LINE
6 - FUEL SUPPLY LINE
7 - FUEL RETURN LINE
8 - BOLTS
9 - FUEL QUANTITY CONTROL VALVE
10 - FUEL TEMPERATURE SENSOR
VAFUEL DELIVERY 14 - 17
Page 1699 of 2305

CAUTION: DO NOT crimp or bend fuel line. Inspect
sealing cone at line; replace line if compression
exists.
NOTE: Care must be taken not to cross the fuel
return and supply lines during installation.
(2) Attach fuel flow supply and return lines,
recrimping clamps using special tool #9539 (Fig. 9).
CAUTION: NEVER slacken the thread connection.
Use a wrench to counterhold at threaded connec-
tion when slackening and tightening torque in order
to avoid also slackening the threaded connection
the next time.
CAUTION: DO NOT crimp or bend fuel line. Inspect
sealing cone at line; replace line if compression
exists.
(3) Attach high pressure fuel line to pump.
Tighten to 22N´m (194 lbs.in.) (Fig. 9).
(4) Install the viscous fan.
(5) Connect negative battery cable.
(6) Start engine, allow to run, turn engine off and
inspect for leaks (Refer to 14 - FUEL SYSTEM -
WARNING), (Refer to 14 - FUEL SYSTEM - DIAG-
NOSIS AND TESTING).
FUEL PUMP MODULE
DESCRIPTION
The fuel pump module is installed in the top of the
fuel tank (Fig. 10). The pump module contains the
following components:
²Electric fuel pump (transfer, or lift pump)
²Fuel reservoir
²Fuel gauge sending unit (fuel level sensor)
²Fuel supply line connection
²Fuel return line connectionFuel is supplied to the high-pressure fuel injection
pump by the low-pressure fuel transfer (lift) pump.
This electric fuel pump is attached to the fuel pump
module and supplies approximately 165 liters/hour
(43.6 gallons/hour). A low-pressure fuel pump is not
attached to the engine.
REMOVAL
CAUTION: To prevent damage to the float rod, the
float and float rod must be removed from the pump
module. This step must be done before the pump
module is removed from the fuel tank.
(1) Drain and remove fuel tank. Refer to Fuel
Tank Removal/Installation.
(2) Thoroughly clean area around pump module at
top of tank.
(3) Disconnect all fuel lines from pump module fit-
tings.
(4) The plastic fuel pump module locknut (lock-
ring) is threaded onto fuel tank. Install Special Tool
#6856 to locknut and remove locknut (Fig. 11). The
fuel pump module will spring up slightly after lock-
nut is removed.
Fig. 10 TOP OF FUEL TANK
1 - Cooler Lines
2-TopofTank
3 - Expansion Tank
4 - Check Valves
5 - Check Valve
6 - Module Lock Ring
7 - Fuel Pump Module
14 - 18 FUEL DELIVERYVA
Page 1700 of 2305
(5) Pull module assembly up just a few inches to
gain access to float support arm/rod (3) (Fig. 12). Be
careful not to bend float support rod while removing
pump module.
(6) Rotate clip (2) (Fig. 13) to release float rod (3)
from fuel level sensor (1).(7) Twist rod (3) slightly (Fig. 14) to remove from
fuel level sensor. Do not allow float assembly to fall
into fuel tank.
(8) While holding float rod, remove fuel pump
module from fuel tank.
(9) Remove float assembly from fuel tank.
(10) Remove and discard rubber gasket (seal) from
pump module.
Fig. 11 FUEL PUMP MODULE R/I
1 - LOCKNUT (LOCKRING)
2 - SPECIAL TOOL #6856
3 - TOP OF PUMP MODULE
Fig. 12 FLOAT ROD CLIP
1 - FUEL LEVEL SENSOR
2 - CLIP
3 - FLOAT ROD
Fig. 13 FLOAT ROD CLIP REMOVAL
1 - FUEL LEVEL SENSOR
2 - CLIP
3 - FLOAT ROD
Fig. 14 FLOAT ROD CLIP REMOVED
1 - FUEL LEVEL SENSOR
2 - CLIP
3 - FLOAT ROD
VAFUEL DELIVERY 14 - 19
Page 1701 of 2305

INSTALLATION
CAUTION: Whenever the fuel pump module is ser-
viced, the rubber gasket must be replaced.
(1) Thoroughly clean locknut (lockring) and lock-
nut threads at top of tank.
(2) Position new gasket (seal) to fuel tank opening.
(3) Position float rod assembly partially into fuel
tank.
(4) Position fuel pump module partially into fuel
tank.
(5) Twist rod (3) (Fig. 15) into clip (2) on fuel level
sensor (1).
(6) Rotate clip (2) (Fig. 16) to attach rod (3) to
clip.(7) After attaching float assembly to fuel level sen-
sor, carefully position fuel pump module into opening
in fuel tank.
(8) Position locknut over top of fuel pump module.
Install locknut finger tight.
(9) The fuel line fittings should be pointed to the
right side of the vehicle. Rotate and position align-
ment arrow (Fig. 17) towards right side of vehicle (if
necessary) before tightening locknut.This step
must be performed to prevent the module's
float from contacting the side of fuel tank.
(10) Tighten locknut using Special Tool #6856.
Refer to Torque Specifications.
(11) Install fuel tank. Refer to Fuel Tank Removal/
Installation.
Fig. 15 FLOAT ROD CLIP INSTALLATION
1 - FUEL LEVEL SENSOR
2 - CLIP
3 - FLOAT ROD
Fig. 16 FLOAT ROD CLIP INSTALLATION
1 - FUEL LEVEL SENSOR
2 - CLIP
3 - FLOAT ROD
14 - 20 FUEL DELIVERYVA
Page 1702 of 2305

FUEL QUANTITY CONTROL
VA LV E
DESCRIPTION
The fuel quantity control valve mounts to front of
the high pressure pump and is controlled by the
ECM. The quantity control valve assists in maintain-
ing proper fuel quantity injected under all operating
conditions. Fuel tank heat protection is also provided
by the quantity control valve. The valve meters the
exact amount of fuel to prevent excess heated fuel
from returning to the tank.
OPERATION
The ECM monitors the fuel system and measures
for pressure vibrations. The ECM will then send a
pulse width signal to the quantity control valve to
regulate the amount of fuel to the high pressure
pump plunger and barrel assemblies. The valve then
adjusts the injection correction quantity for each
individual cylinder in line with the firing order, there
by eliminating the pressure resonance in the fuel rail
and improving each independent injectors operation.
The fuel quantity valve also interrupts the fuel sup-
ply to the high pressure pump plunger and barrel
assemblies when the engine is switched off.
The ECM detects the operating state which exists
at the engine by means of the sensors. In order to
adapt the quantity injected, either the rail pressure
can be adjusted by way of the pressure regulator
valve and the quantity control valve, or the actuationtime of the solenoid valves in the fuel injectors can
be extended or shortened.
Fuel quantity control is performed under the fol-
lowing operating conditions:
²Approximately 30 seconds after the engine has
started
²Fuel temperature > 20ÉC (68ÉF)
²Engine not in deceleration mode
REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect the control valve wiring harness
connector (Fig. 18).
(3) Remove the valve fasteners and remove the
control valve (Fig. 18).
INSTALLATION
(1) Clean sealing surfaces.
(2) Install new seal on sensor.
(3) Position the control valve on to the high pres-
sure pump and install fasteners (Fig. 19).
(4) Connect wiring harness connector to control
valve (Fig. 19).
(5) Connect negative battery cable.
(6) Start the engine, allow to run, turn engine off
and inspect for leaks (Refer to 14 - FUEL SYSTEM/
FUEL INJECTION - WARNING).
Fig. 17 ALIGN PUMP MODULE
1 - LOCKNUT
2 - ALIGNMENT ARROW (POSITION TOWARDS RIGHT SIDE OF
VEHICLE)
Fig. 18 HIGH PRESSURE FUEL PUMP
1 - HIGH PRESSURE PUMP
2 - FUEL SUPPY TO FUEL RAIL
3 - FUEL SUPPLY LINE
4 - FUEL RETURN LINE
5 - FUEL TEMPERATURE SENSOR
6 - FUEL QUANTITY CONTROL VALVE
7 - OIL LEVEL INDICATOR
8 - VACUUM PUMP
VAFUEL DELIVERY 14 - 21
Page 1703 of 2305

FUEL RAIL
DESCRIPTION
The fuel rail acts like a high pressure store. It is
available to all injectors for drawing fuel which has
been compressed by the high pressure injection
pump. The rail pressure sensor, rail pressure control
valve, high pressure line, and the return flow line
are attached to the fuel rail.
OPERATION
The stored fuel volume inside the rail acts as a
damper for pressure fluctuations which result
because of pulsating supply and brief large extrac-
tions of fuel during injector firing. The rail primarily
influences the atomization of fuel at the injector noz-
zle, and the accuracy of injected quantity during
injection.
REMOVAL
(Refer to 14 - FUEL SYSTEM - WARNING).
WARNING: NO SPARKS, OPEN FLAMES OR SMOK-
ING. RISK OF POISONING FROM INHALING AND
SWALLOWING FUEL. RISK OF INJURY TO EYES
AND SKIN FROM CONTACT WITH FUEL. POUR
FUELS ONLY INTO SUITABLE AND APPROPRI-
ATELY MARKED CONTAINERS. WEAR PROTECTIVE
CLOTHING.
(1) Disconnect negative battery cable.
(2) Remove the engine cover.
(3) Disconnect the intake manifold air inlet duct
and position aside.
(4) Disconnect the fuel rail pressure and control
valve wiring harness connectors.
(5) Remove engine harness retaining bolts and
unclip the engine harness from the fuel rail.
(6) Remove injector high pressure lines (Fig. 19)
(7) Remove fuel rail retaining bolts (Fig. 19).
CAUTION: When slackening and tightening fuel
injection line union nuts, counter hold with wrench
at threaded connection. ON NO ACCOUNT exceed
the tightening torque at any time. Do NOT crimp or
bend lines.
NOTE: After removing lines, seal connections and
ensure cleanliness.(8) Detach fuel return flow line to high pressure
pump at rail
(9) Detach fuel return flow line at banjo bolt (Fig.
19)
(10) Remove fuel rail.
INSTALLATION
(Refer to 14 - FUEL SYSTEM - WARNING)
WARNING: NO FIRE, FLAMES OR SMOKING. RISK
OF POISONING FROM INHALING OR SWALLOWING
FUEL. RISK OF INJURY TO EYES AND SKIN FROM
CONTACT WITH FUEL. POUR FUELS ONLY INTO
SUITABLE AND APPROPRIATELY MARKED CON-
TAINERS. WEAR PROTECTIVE CLOTHING.
(1) Loosely position fuel rail into proper position
on the cylinder head and hand tighten the fasteners.
(2) Connect the fuel pressure control valve harness
connector (Fig. 19).
(3) Connect the fuel return lines at the banjo bolt
(Fig. 19).
CAUTION: Inspect sealing cones at the lines.
Replace as necessary. Ensure that all fuel pressure
lines are exactly located in original position.
(4) Install the high pressure fuel lines and hand
tighten.
Fig. 19 FUEL RAIL
1 - CAMSHAFT POSITION SENSOR
2 - FUEL INJECTOR
3 - FUEL INJECTOR VALLEY DRAIN
4 - FUEL RAIL PRESSURE CONTROL VALVE
5 - BANJO BOLT
6 - FUEL RAIL
7 - HIGH PRESSURE FUEL LINE
14 - 22 FUEL DELIVERYVA
Page 1704 of 2305

(5) Tighten fuel rail bolts to 14 N´m (124 in. lbs.)
(Fig. 19)
CAUTION: When tightening fuel injection line union
nuts, counter hold with a wrench at the thread con-
nection. ON NO ACCOUNT exceed the tightening
torque at any time.
(6) Tighten the pressure line to the fuel rail to 20
N´m (177 in. lbs.).
(7) Tighten the high pressure fuel lines at the fuel
rail to 22 N´m (195 in. lbs.).
(8) Reconnect engine harness electrical connectors.
(9) Connect the intake manifold air inlet duct.
(10) Connect negative battery cable.
CAUTION: Care must be taken when installing the
engine cover. Assure the proper routing of the fuel
injector return fuel hose to the banjo bolt fitting in
the left rear corner of the cover. Failure to do so
may pinch or damage the hose causing fuel leakage
or a driveability concern.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH FAN. DO NOT PUT YOUR
HANDS NEAR PULLEYS, BELTS OR FAN. DO NOT
WEAR LOOSE CLOTHING.
(11) Start engine, run for a few minutes, turn the
engine off and inspect for leaks (Refer to 14 - FUEL
SYSTEM - WARNING).
FUEL TANK
DESCRIPTION
The plastic fuel tank (Fig. 20) is mounted to the
frame rails under the left/center side of the vehicle.
The fuel tank contains a serviceable fuel pump mod-
ule with an electric fuel pump, and a fuel level send-
ing unit. The tank is also equipped with 2 fuel lines:
a fuel supply line to the fuel pump, and a separate
fuel return line.
Fuel Temperature Control:A section of the fuel
return line is coiled at the rear section of the tank
(Fig. 21). This coiled section is used to help drop the
temperature of fuel returning to the tank. A thermo-
stat (preheating valve) (3) (Fig. 21) is used to keep
fuel temperature below 167 degrees F. If fuel temper-
ature is above 167 degrees F, fuel passes first
through the coiled cooler lines, and then into the fuel
tank. If fuel temperature is below 150 degrees F, fuel
bypasses the coiled cooler lines, and is returned
directly into the fuel tank.
An electric fuel pump (more commonly referred to
in diesel applications as a fuel transfer pump or fuel
lift pump) is attached to the fuel pump module. Thismodule (Fig. 22) is located in the fuel tank. Refer to
Fuel Pump Module for additional information.
VAFUEL DELIVERY 14 - 23