Fuel pump line JEEP GRAND CHEROKEE 2003 WJ / 2.G User Guide

(3) Install intake manifold on the cylinder head
dowels.
(4) Install washer and fastener Numbers 1, 2, 4, 5,
8, 9, 10 and 11 (Fig. 84).
(5) Install washer and fastener Numbers 6 and 7
(Fig. 84).
(6) Tighten the fasteners in sequence and to the
specified torque (Fig. 84).
²Fastener Numbers 1 through 5ÐTighten to 33
N´m (24 ft. lbs.) torque.
²Fastener Numbers 6 and 7ÐTighten to 31 N´m
(23 ft. lbs.) torque.
²Fastener Numbers 8 through 11ÐTighten to 33
N´m (24 ft. lbs.) torque.
(7) Install the power steering pump to the intake
manifold.
(8) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(9) Install the fuel system supply line to the fuel
rail assembly.
(10) Connect all electrical connections on the
intake manifold.
(11) Connect the vacuum hoses previously
removed.
(12) Install throttle cable, vehicle speed control
cable (if equipped).
(13) Install the transmission line pressure cable (if
equipped) (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - AW4/THROTTLE VALVE
CABLE - INSTALLATION).
(14) Install air cleaner assembly.
(15) Connect air inlet hose to the resonator assem-
bly.
(16) Raise the vehicle.
(17) Connect the exhaust pipes to the engine
exhaust manifolds. Tighten the bolts to 31 N´m (23
ft. lbs.)
(18) Lower the vehicle.(19) Connect the battery negative cable.
(20) Start the engine and check for leaks.
EXHAUST MANIFOLD
DESCRIPTION
The two exhaust manifolds (Fig. 85) are log style
and are made of high silicon molybdenum cast iron.
The exhaust manifolds share a common gasket with
the intake manifold. The exhaust manifolds also
incorporate ball flange outlets for improved sealing
and strain free connections.
REMOVAL
The intake and engine exhaust manifolds on the
4.0L engine must be removed together. The manifolds
use a common gasket at the cylinder head.
(Refer to 9 - ENGINE/MANIFOLDS/INTAKE
MANIFOLD - REMOVAL).
INSTALLATION
(1) The exhaust manifold and the intake manifold
must be installed together using a common gasket.
(2) (Refer to 9 - ENGINE/MANIFOLDS/INTAKE
MANIFOLD - INSTALLATION).
TIMING BELT / CHAIN
COVER(S)
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the vibration damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL).
(3) Remove the fan, hub assembly and fan shroud
(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
REMOVAL).
(4) Remove the accessory drive brackets that are
attached to the timing case cover.
(5) Remove the A/C compressor (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - REMOVAL) (if equipped) and gen-
erator bracket assembly from the engine cylinder
head and move to one side.
(6) Remove the oil pan-to-timing case cover bolts
and timing case cover-to-cylinder block bolts.
(7) Remove the timing case cover and gasket from
the engine.
(8) Pry the crankshaft oil seal from the front of the
timing case cover (Fig. 86).
INSTALLATION
Clean the timing case cover, oil pan and cylinder
block gasket surfaces.
Fig. 84 Intake and Exhaust Manifolds Installation
9 - 58 ENGINE - 4.0LWJ
INTAKE MANIFOLD (Continued)

(13) Disconnect the engine block heater power
cable from the block heater.
(14) Lower vehicle.
(15) Remove throttle body resonator assembly and
inlet hose.
(16) Disconnect throttle and speed control cables.
(17) Disconnect tube from both the left and right
side crankcase breathers, then remove the breathers
(Fig. 5).
(18) Discharge A/C system (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE).(19) Remove radiator fan (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - REMOVAL) and acces-
sory drive belt (Refer to 7 - COOLING/ACCESSORY
DRIVE/DRIVE BELTS - REMOVAL).
(20) Remove A/C compressor (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/A/C COM-
PRESSOR - REMOVAL).
(21) Disconnect transmission oil cooler lines at the
radiator.
(22) Disconnect radiator lower hose at the thermo-
stat housing.
(23) Remove A/C condenser (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/A/C CON-
DENSER - REMOVAL).
(24) Remove radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - REMOVAL).
(25) Remove generator (Refer to 8 - ELECTRICAL/
CHARGING/GENERATOR - REMOVAL).
(26) Disconnect the two heater hoses from the tim-
ing chain cover.
(27) Disconnect engine harness at the following
points :
²Intake air temperature (IAT) sensor (Fig. 6)
²Fuel Injectors
²Throttle Position (TPS) Switch
²Idle Air Control (IAC) Motor
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold absolute pressure (MAP) Sensor
²Camshaft Position (CMP) Sensor
²Coil Over Plugs
(28) Release fuel rail pressure (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - STANDARD PROCE-
DURE) then disconnect the fuel supply quick connect
fitting at the fuel rail (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY/QUICK CONNECT FITTING -
STANDARD PROCEDURE).
(29) Remove power steering pump and position out
of the way.
(30) Disconnect ground straps from the left side of
the engine.
(31) Install Engine Lifting Fixture Special Tool
8347 (Fig. 7)following these steps.
²Holding the lifting fixture at a slight angle, slide
the large bore in the front plate over the hex portion
of the lifting stud.
²Position the two remaining fixture arms onto
the two lifting studs in the cylinder heads.
²Pull foward and upward on the lifting fixture so
that the lifting stud rest in the slotted area below the
large bore.
²Secure the lifting fixture to the three studs
using three 7/16 ± 14 N/C locknuts.
²Make sure the lifting loop in the lifting fixture is
in the last hole (closest to the throttle body) to min-
imize the angle of engine during removal.
Fig. 4 Crankshaft Position Sensor
1 - CRANKSHAFT POSITION SENSOR
2 - CYLINDER HEAD COVER
3 - CAMSHAFT POSITION SENSOR
4 - RIGHT SIDE CYLINDER BLOCK
Fig. 5 Crankcase Breather Connection Points
1 - CRANKCASE BREATHERS
9 - 72 ENGINE - 4.7LWJ
ENGINE - 4.7L (Continued)

(32) Disconnect body ground strap at the right side
cowl.
NOTE: It will be necessary to support the transmis-
sion in order to remove the engine.
(33) Position a suitable jack under the transmis-
sion.
(34) Remove the engine mount through bolts.
(35) Raise engine slightly, then remove both left
and right side engine mounts from engine. (Refer to
9 - ENGINE/ENGINE MOUNTING/FRONT MOUNT
- REMOVAL).
(36) Remove engine from the vehicle.
INSTALLATION
(1) Position engine in the vehicle.
(2) Install both left and right side engine mounts
onto engine (Refer to 9 - ENGINE/ENGINE MOUNT-
ING/FRONT MOUNT - INSTALLATION).
(3) Install transmission to engine mounting bolts.
Tighten the bolts to 41 N´m (30 ft. lbs.).(4) Remove jack from under the transmission.
(5) Remove engine lifting fixture special tool 8347
(Fig. 7).
(6) Connect ground straps on the left side of the
engine.
(7) Install power steering pump (Refer to 19 -
STEERING/PUMP - INSTALLATION).
(8) Connect fuel supply line quick connect fitting
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY/
QUICK CONNECT FITTING - STANDARD PROCE-
DURE).
(9) Connect engine harness at the following points
(Fig. 6):
²Intake Air Temperature (IAT) Sensor
²Idle Air Control (IAC) Motor
²Fuel Injectors
²Throttle Position (TPS) Switch
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold Absolute Pressure (MAP) Sensor
Fig. 6 Throttle Body Connection Points
1 - THROTTLE BODY
2 - TPS
3 - IAC MOTOR
4 - IAT SENSOR (THREADED TYPE)
5 - MOUNTING SCREWS
Fig. 7 Engine Lifting Fixture Attachment Locations
1 - ATTACHING LOCATION
2 - ADJUSTABLE HOOK
3 - SPECIAL TOOL 8347 ENGINE LIFT FIXTURE
4 - ATTACHING LOCATIONS
WJENGINE - 4.7L 9 - 73
ENGINE - 4.7L (Continued)

FUEL SYSTEM
TABLE OF CONTENTS
page page
FUEL DELIVERY..........................1FUEL INJECTION........................31
FUEL DELIVERY
TABLE OF CONTENTS
page page
FUEL DELIVERY
DESCRIPTION..........................2
OPERATION............................2
DIAGNOSIS AND TESTING
FUEL PRESSURE LEAK DOWN TEST......2
STANDARD PROCEDURE - FUEL SYSTEM
PRESSURE RELEASE...................4
SPECIFICATIONS
FUEL SYSTEM PRESSURE..............4
TORQUE - FUEL DELIVERY..............4
SPECIAL TOOLS
FUEL SYSTEM........................5
FUEL FILTER/PRESSURE REGULATOR
DESCRIPTION..........................5
OPERATION............................5
REMOVAL.............................6
INSTALLATION..........................6
FUEL LEVEL SENDING UNIT / SENSOR
DESCRIPTION..........................7
OPERATION............................7
DIAGNOSIS AND TESTING - FUEL LEVEL
SENDING UNIT........................7
REMOVAL.............................7
INSTALLATION..........................8
FUEL LINES
DESCRIPTION..........................8
FUEL PUMP
DESCRIPTION..........................8
OPERATION............................9
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - FUEL PUMP
CAPACITY TEST.......................9
DIAGNOSIS AND TESTING - FUEL PUMP
AMPERAGE TEST......................9FUEL PUMP PRESSURE TEST...........11
FUEL PUMP MODULE
DESCRIPTION.........................13
OPERATION...........................13
REMOVAL.............................13
INSTALLATION.........................14
FUEL RAIL
DESCRIPTION
DESCRIPTION - 4.7L...................15
DESCRIPTION - 4.0L...................15
OPERATION
OPERATION - 4.7L....................15
OPERATION - 4.0L....................15
REMOVAL
REMOVAL - 4.7L......................15
REMOVAL - 4.0L......................17
INSTALLATION
INSTALLATION - 4.7L..................18
INSTALLATION - 4.0L..................18
FUEL TANK
DESCRIPTION.........................19
OPERATION...........................19
REMOVAL.............................19
INSTALLATION.........................20
INLET FILTER
REMOVAL.............................27
INSTALLATION.........................27
QUICK CONNECT FITTING
DESCRIPTION.........................27
STANDARD PROCEDURE - QUICK-CONNECT
FITTINGS...........................27
WJFUEL SYSTEM 14 - 1

FUEL DELIVERY
DESCRIPTION
The fuel delivery system consists of:
²the fuel pump module containing the electric
fuel pump, fuel gauge sending unit (fuel level sensor)
and a separate fuel filter located at bottom of pump
module
²a separate combination fuel filter/fuel pressure
regulator
²fuel tubes/lines/hoses
²quick-connect fittings
²fuel injector rail
²fuel injectors
²fuel tank
²fuel tank filler/vent tube assembly
²fuel tank filler tube cap
²accelerator pedal
²throttle cable
OPERATION
The fuel tank assembly consists of: the fuel tank,
fuel tank shield, fuel tank straps, fuel pump module
assembly, fuel pump module locknut/gasket, and fuel
tank check valve (refer to Emission Control System
for fuel tank check valve information).
A fuel filler/vent tube assembly using a pressure/
vacuum, 1/4 turn fuel filler cap is used. The fuel
filler tube contains a flap door located below the fuel
fill cap.
Also to be considered part of the fuel system is the
evaporation control system. This is designed to
reduce the emission of fuel vapors into the atmo-
sphere. The description and function of the Evapora-
tive Control System is found in Emission Control
Systems.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.
DIAGNOSIS AND TESTING
FUEL PRESSURE LEAK DOWN TEST
Use this test in conjunction with the Fuel Pump
Pressure Test and Fuel Pump Capacity Test.
Check Valve Operation:The electric fuel pump
outlet contains a one-way check valve to prevent fuel
flow back into the tank and to maintain fuel supply
line pressure (engine warm) when pump is not oper-
ational. It is also used to keep the fuel supply line
full of gasoline when pump is not operational. After
the vehicle has cooled down, fuel pressure may drop
to 0 psi (cold fluid contracts), but liquid gasoline willremain in fuel supply line between the check valve
and fuel injectors.Fuel pressure that has
dropped to 0 psi on a cooled down vehicle
(engine off) is a normal condition.When the elec-
tric fuel pump is activated, fuel pressure should
immediately(1±2 seconds) rise to specification.
Abnormally long periods of cranking to restart a
hotengine that has been shut down for a short
period of time may be caused by:
²Fuel pressure bleeding past a fuel injector(s).
²Fuel pressure bleeding past the check valve in
the fuel pump module.
²A defective fuel filter/pressure regulator.
Two #6539, 5/16º, Fuel Line Pressure Test Adapter
Hose Tools are required for the following tests.
(1) Release fuel system pressure. Refer to Fuel
Pressure Release Procedure.
(2) Raise vehicle.
Fuel Line Identification:The fuel filter/pressure
regulator is located in front of the fuel tank and
above the rear axle. It is transversely mounted to a
chassis crossmember (left-to-right). The filter/regula-
tor is equipped with 3 fuel line fittings (2 at one end
and 1 at the other end). The single fitting facing the
left side of the vehicle is the supply line to the fuel
rail (Fig. 1) . The 2 fittings facing the right side of
the vehicle are connected to the fuel tank. Of these 2
fittings, the fitting towards thefrontis used for fuel
return to the fuel tank. The fitting towards therear
is a pressure line. Thisrearfitting must be discon-
nected for the following step.
(3) See previous step. Disconnect fuel pressure line
atrearof filter/regulator. This is a 5/169quick-con-
nect fitting (Fig. 1) . Refer to Quick-Connect Fittings
for procedures.
(4) Obtain correct Fuel Line Pressure Test Adapter
Hose Tool # 6539 for 5/16º fuel lines. Connect one
end of this Special Tool into the disconnected fuel
pressure line. Connect the other end of the Tool into
fitting on filter/regulator.
(5) Lower vehicle.
(6) Disconnect the fuel inlet line at fuel rail. Refer
to Quick-Connect Fittings for procedures. On some
engines, air cleaner housing removal may be neces-
sary before fuel line disconnection.
(7) Obtain a second Fuel Line Pressure Test
Adapter Hose Tool # 6539 for 5/16º fuel lines. Con-
nect this tool between disconnected fuel line and fuel
rail (Fig. 2) .
(8) Connect the 0-414 kPa (0-60 psi) fuel pressure
test gauge (from Gauge Set 5069) to the test port on
the appropriate Adaptor Tool.NOTE: The DRB III
Scan Tool along with the PEP module, the 500
psi pressure transducer, and the transducer-to-
test port adapter may also be used in place of
the fuel pressure gauge.
14 - 2 FUEL DELIVERYWJ

CAUTION: The fittings on both tools must be in
good condition and free from any small leaks
before performing the proceeding test.
(9) Start engine and bring to normal operating
temperature.
(10) Observe fuel pressure test gauge (or DRB
screen). Normal operating pressure should be 339
kPa   34 kPa (49.2 psi   5 psi).
(11) Shut engine off.
(12) Pressure should not fall below30 psi for five
minutes.
(13) If pressure falls below 30 psi, it must be
determined if a fuel injector, the supply check valve
within the fuel pump module, the fuel filter/pressure
regulator, or a fuel tube/line is leaking.
(14) Again, start engine and bring to normal oper-
ating temperature.
(15) Shut engine off.
(16)Testing for fuel injector or fuel rail leak-
age:Clamp off the rubber hose portion of the 6539
Adaptor Tool between the fuel rail and the test port
ªTº on Adapter Tool (be sure clamping pressure issufficient). If pressure now holds at or above 30 psi, a
fuel injector or the fuel rail is leaking.
(17) Again, start engine and bring to normal oper-
ating temperature.
(18) Shut engine off.
(19) Raise vehicle.
(20)Testing for fuel filter/pressure regulator
leakage:While continuing to securely clamp
between the fuel rail and the test port9T9on Adaptor
Tool 6539, securely clamp offanyrubber hose por-
tion of the Adaptor Tool 6539 that was installed
between the fuel pressure line and the filter/regula-
tor fitting (by restricting the pump module supply
line's backflow, you isolate any leakdown originating
from the filter/regulator via the tank return line.) If
the pressure falls below 30 psi within 5 minutes, the
filter/regulator is leaking. If it now holds at or above
30 psi, the electric fuel pump check valve is leaking
or a fuel tube/line is leaking. A fuel odor presence
would indicate the latter.
The electric fuel pump is not serviced separately. If
replacement is necessary, replace the fuel pump mod-
ule assembly. The filter/regulator may be replaced
separately. Refer to Fuel Filter/Fuel Pressure Regu-
lator Removal/Installation for additional information.
Fig. 1 Disconnect Fuel Pressure Line at Filter/
Regulator
1 - FUEL SUPPLY LINE (TO FUEL RAIL)
2 - EVAP LINE
3 - FUEL RETURN LINE (MALE)
4 - FUEL PRESSURE LINE (FEMALE)
5 - FUEL FILTER/PRESSURE REGULATOR
6 - FUEL TANK
Fig. 2 Connecting Adapter ToolÐTypical
1 - VEHICLE FUEL LINE
2 - TEST PORT ªTº
3 - SPECIAL TOOL 6923, 6631, 6541 OR 6539
4 - FUEL PRESSURE TEST GAUGE
5 - FUEL LINE CONNECTION AT RAIL
6 - FUEL RAIL
WJFUEL DELIVERY 14 - 3
FUEL DELIVERY (Continued)

STANDARD PROCEDURE - FUEL SYSTEM
PRESSURE RELEASE
Use following procedure if the fuel injector
rail is, or is not equipped with a fuel pressure
test port.
(1) Remove fuel fill cap.
(2) Remove fuel pump relay from Power Distribu-
tion Center (PDC). For location of relay, refer to label
on underside of PDC cover.
(3) Start and run engine until it stalls.
(4) Attempt restarting engine until it will no
longer run.
(5) Turn ignition key to OFF position.
CAUTION: Steps 1, 2, 3 and 4 must be performed to
relieve high pressure fuel from within fuel rail. Do
not attempt to use following steps to relieve this
pressure as excessive fuel will be forced into a cyl-
inder chamber.
(6) Unplug connector from any fuel injector.
(7) Attach one end of a jumper wire with alligator
clips (18 gauge or smaller) to either injector terminal.(8) Connect other end of jumper wire to positive
side of battery.
(9) Connect one end of a second jumper wire to
remaining injector terminal.
CAUTION: Powering an injector for more than a few
seconds will permanently damage the injector.
(10) Momentarily touch other end of jumper wire
to negative terminal of battery for no more than a
few seconds.
(11) Place a rag or towel below fuel line quick-con-
nect fitting at fuel rail.
(12) Disconnect quick-connect fitting at fuel rail.
Refer to Quick-Connect Fittings.
(13) Return fuel pump relay to PDC.
(14) One or more Diagnostic Trouble Codes (DTC's)
may have been stored in PCM memory due to fuel
pump relay removal. The DRBtscan tool must be
used to erase a DTC.
SPECIFICATIONS
FUEL SYSTEM PRESSURE
339 kPa   34 kPa (49.2 psi   5 psi).
TORQUE - FUEL DELIVERY
DESCRIPTION N-m Ft. Lbs. In. Lbs.
Accelerator Pedal Bracket Mounting Nuts
(without adjustable pedals)12  2 - 105  20
Fuel Filter/Fuel Press. Reg. Bolts 3 - 26
Fuel Hose Clamps 3 - 26
Fuel Injector Rail Mounting Bolts -4.0L Engine 11 - 100
Fuel Injector Rail Mounting Bolts -4.7L V-8
Engine11 - 100
Fuel Pump Module Locknut 74 55 -
Fuel Tank Filler Tube-to-Body Mounting Bolts 2 - 15
Fuel Tank-to-Body Mounting Bolts 88 65 -
Fuel Tank Support Bracket Bolts (large brackets) 88 65 -
Fuel Tank Support Bracket Bolts (small bracket) 5 - 45
Fuel Tank Support Bracket Nuts (large brackets) 61 45 -
Fuel Tank Heat Shield Nuts (shield-to-tank) 9 - 85
Fuel Tank Heat Shield Nuts (shield-to-body) 3 - 25
14 - 4 FUEL DELIVERYWJ
FUEL DELIVERY (Continued)

The regulator is calibrated to maintain fuel system
operating pressure of approximately 339 kPa   34
kPa (49.2 psi   5 psi) at the fuel injectors. It contains
a diaphragm, calibrated springs and a fuel return
valve. The internal fuel filter is also part of the
assembly.
Fuel is supplied to the filter/regulator by the elec-
tric fuel pump. The regulator acts as a check valve to
maintain some fuel pressure when the engine is not
operating. This will help to start the engine. A second
check valve is located at the outlet end of the electric
fuel pump.
If fuel pressure at the pressure regulator exceeds
approximately 49 psi, an internal diaphragm closes.
Excess fuel is then routed into a separate fuel return
line and returned to the fuel tank through the top of
the fuel pump module.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.
REMOVAL
The combination Fuel Filter/Fuel Pressure Regula-
tor is remotely mounted to the vehicle body, above
the rear axle and near the front of the fuel tank (Fig.
4) or (Fig. 5).
(1) Perform Fuel System Pressure Release Proce-
dure.
(2) Disconnect negative battery cable at battery.
(3) Raise vehicle.
(4) Clean area around 3 filter/regulator fittings.
(5) Disconnect fuel supply, fuel return and fuel
pressure lines at filter/regulator (Fig. 4) . Refer to
Quick-Connect Fittings.
(6) Remove 2 mounting bolts (Fig. 5) and remove
filter/regulator.
INSTALLATION
The combination Fuel Filter/Fuel Pressure Regula-
tor is remotely mounted to the vehicle body, above
the rear axle and near the front of the fuel tank (Fig.
4) or (Fig. 5).
(1) Before installing filter/regulator, be sure all fit-
tings are cleaned of all dirt and contaminants.
(2) Be sure o-ring is positioned into fuel return fit-
ting in filter/regulator.
Fig. 3 Fuel Filter/Fuel Pressure Regulator Location
1 - FUEL SUPPLY LINE (TO FUEL RAIL)
2 - EVAP LINE
3 - FUEL RETURN LINE (MALE)
4 - FUEL PRESSURE LINE (FEMALE)
5 - FUEL FILTER/PRESSURE REGULATOR
6 - FUEL TANK
Fig. 4 Fuel Filter/Fuel Pressure Regulator Location
1 - FUEL SUPPLY LINE (TO FUEL RAIL)
2 - EVAP LINE
3 - FUEL RETURN LINE (MALE)
4 - FUEL PRESSURE LINE (FEMALE)
5 - FUEL FILTER/PRESSURE REGULATOR
6 - FUEL TANK
14 - 6 FUEL DELIVERYWJ
FUEL FILTER/PRESSURE REGULATOR (Continued)

(1) Remove fuel tank. Refer to Fuel Tank Removal/
Installation.(2) Remove fuel pump module. Refer to Fuel Pump
Module Removal/Installation.
(3) Remove electrical wire connector at sending
unit terminals.
(4) Press upward on release tab (Fig. 7) to remove
sending unit from pump module.
INSTALLATION
The fuel gauge sending unit (fuel level sensor) and
float assembly is located on the side of fuel pump
module (Fig. 6). The fuel pump module is located
within the fuel tank.
(1) Position sending unit to pump module and
snap into place.
(2) Connect electrical connector to terminals.
(3) Install fuel pump module. Refer to Fuel Pump
Module Removal/Installation.
(4) Install fuel tank. Refer to Fuel Tank Removal/
Installation.
FUEL LINES
DESCRIPTION
Also refer to Quick-Connect Fittings.
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE (EVEN WITH THE ENGINE OFF).
BEFORE SERVICING ANY FUEL SYSTEM HOSES,
FITTINGS OR LINES, THE FUEL SYSTEM PRES-
SURE MUST BE RELEASED. REFER TO THE FUEL
SYSTEM PRESSURE RELEASE PROCEDURE IN
THIS GROUP.
The lines/tubes/hoses used on fuel injected vehicles
are of a special construction. This is due to the
higher fuel pressures and the possibility of contami-
nated fuel in this system. If it is necessary to replace
these lines/tubes/hoses, only those marked EFM/EFI
may be used.
If equipped:The hose clamps used to secure rub-
ber hoses on fuel injected vehicles are of a special
rolled edge construction. This construction is used to
prevent the edge of the clamp from cutting into the
hose. Only these rolled edge type clamps may be
used in this system. All other types of clamps may
cut into the hoses and cause high-pressure fuel leaks.
Use new original equipment type hose clamps.
FUEL PUMP
DESCRIPTION
The electric fuel pump is located inside of the fuel
pump module. A 12 volt, permanent magnet, electric
motor powers the fuel pump. The electric fuel pump
is not a separate, serviceable component.
Fig. 6 Fuel Gauge Sending Unit Location
1 - FUEL PUMP MODULE
2 - FUEL GAUGE FLOAT
3 - ELECTRIC FUEL PUMP
4 - INLET FILTER
5 - FUEL GAUGE SENDING UNIT
6 - PIGTAIL HARNESS
Fig. 7 Fuel Gauge Sending Unit Release Tab
1 - ELECTRICAL CONNECTOR
2 - FUEL GAUGE SENDING UNIT
3 - RELEASE TAB
4 - FUEL PUMP MODULE
14 - 8 FUEL DELIVERYWJ
FUEL LEVEL SENDING UNIT / SENSOR (Continued)

OPERATION
Voltage to operate the electric pump is supplied
through the fuel pump relay.
Fuel is drawn in through a filter at the bottom of
the module and pushed through the electric motor
gearset to the pump outlet.
Check Valve Operation:The pump outlet con-
tains a one-way check valve to prevent fuel flow back
into the tank and to maintain fuel supply line pres-
sure (engine warm) when pump is not operational. It
is also used to keep the fuel supply line full of gaso-
line when pump is not operational. After the vehicle
has cooled down, fuel pressure may drop to 0 psi
(cold fluid contracts), but liquid gasoline will remain
in fuel supply line between the check valve and fuel
injectors.Fuel pressure that has dropped to 0
psi on a cooled down vehicle (engine off) is a
normal condition.Refer to the Fuel Pressure Leak
Down Test for more information.
The electric fuel pump is not a separate, service-
able component.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - FUEL PUMP
CAPACITY TEST
Before performing this test, verify fuel pump
pressure. Refer to Fuel Pump Pressure Test.
Use this test in conjunction with the Fuel Pres-
sure Leak Down Test.
(1) Release fuel system pressure. Refer to Fuel
Pressure Release Procedure.
(2) Disconnect fuel supply line at fuel rail. Refer to
Quick-Connect Fittings. Some engines may require
air cleaner housing removal before line disconnection.
(3) Obtain correct Fuel Line Pressure Test Adapter
Tool Hose. Tool number 6539 is used for 5/16º fuel
lines and tool number 6631 is used for 3/8º fuel lines.
(4) Connect correct Fuel Line Pressure Test
Adapter Tool Hose into disconnected fuel supply line.
Insert other end of Adaptor Tool Hose into a gradu-
ated container.
(5) Remove fuel fill cap.
(6) To activate fuel pump and pressurize system,
obtain DRBtscan tool and actuate ASD Fuel System
Test.
(7) A good fuel pump will deliver at least 1/4 liter
of fuel in 7 seconds. Do not operate fuel pump for
longer than 7 seconds with fuel line disconnected as
fuel pump module reservoir may run empty.
(a) If capacity is lower than specification, but
fuel pump can be heard operating through fuel fill
cap opening, check for a kinked/damaged fuel sup-
ply line somewhere between fuel rail and fuel
pump module.(b) If line is not kinked/damaged, and fuel pres-
sure is OK, but capacity is low, replace fuel filter/
fuel pressure regulator. The filter/regulator may be
serviced separately on certain applications. Refer
to Fuel Filter/Fuel Pressure Regulator Removal/In-
stallation for additional information.
(c) If both fuel pressure and capacity are low,
replace fuel pump module assembly. Refer to Fuel
Pump Module Removal/Installation.
DIAGNOSIS AND TESTING - FUEL PUMP
AMPERAGE TEST
This amperage (current draw) test is to be done in
conjunction with the Fuel Pump Pressure Test, Fuel
Pump Capacity Test and Fuel Pressure Leak Down
Test. Before performing the amperage test, be sure
the temperature of the fuel tank is above 50É F (10É
C).
The DRBtScan Tool along with the DRB Low Cur-
rent Shunt (LCS) adapter (Fig. 8) and its test leads
will be used to check fuel pump amperage specifica-
tions.
(1) Be sure fuel tank contains fuel before starting
test. If tank is empty or near empty, amperage read-
ings will be incorrect.
(2) Obtain LCS adapter.
(3) Plug cable from LCS adapter into DRB scan
tool at SET 1 receptacle.
(4) Plug DRB into vehicle 16±way connector (data
link connector).
Fig. 8 LOW CURRENT SHUNT
1 - LOW CURRENT SHUNT ADAPTER
2 - PLUG TO DRB
3 - TEST LEAD RECEPTACLES
WJFUEL DELIVERY 14 - 9
FUEL PUMP (Continued)