DODGE TRUCK 1993 Service Repair Manual

Page 821 of 1502


14
- 2
FUEL SYSTEM


GASOLINE/OXYGENATE
BLENDS

Some fuel suppliers blend unleaded gasoline with
materials that contain oxygen such as alcohol, MTBE and ETBE. The type and amount of oxygenate used
in the blend is important. The following are gener­
ally used in gasoline blends:

ETHANOL
Ethanol (Ethyl or Grain Alcohol) properly blended,
is used as a mixture of 10 percent ethanol and 90
percent gasoline. Gasoline with ethanol may be
used in your vehicle.

METHANOL

CAUTION:
DO NOT USE
GASOLINES CONTAINING
METHANOL.
Use of methanol/gasoline blends may re­
sult in starting and driveability problems. In addition,
damage may be done to critical fuel system compo­
nents.

Methanol (Methyl or Wood Alcohol) is used in a va­
riety of concentrations blended with unleaded gaso­
line.
You may encounter fuels containing 3 percent
or more methanol along with other alcohols called co-
solvents.
Problems that are the result of using methanol/gas­
oline blends are not the responsibility of Chrysler Corporation. They may not be covered by the vehicle
warranty.

MTBE/ETBE
Gasoline and MTBE (Methyl Tertiary Butyl Ether)
blends are a mixture of unleaded gasoline and up to 15 percent
MTBE.
Gasoline and
ETBE
(Ethyl
Ter­

tiary Butyl Ether) are blends of gasoline and up to 17 percent ETBE. Gasoline blended with MTBE or
ETBE may be used in your vehicle.

CLEAN
AIR GASOLINE Many gasolines are now being blended that con­
tribute to cleaner air, especially in those areas of the
country where air pollution levels are high. These
new blends provide a cleaner burning fuel and some are referred to as Reformulated Gasoline.
In areas of the country where carbon monoxide lev­
els are high, gasolines are being treated with oxy­
genated materials such as MTBE, ETBE and ethanol.
Chrysler Corporation supports these efforts toward
cleaner air and recommends that you use these gas­
olines as they become available.

FUEL
REQUIREMENTS-DIESEL ENGINE
Use good quality diesel fuel from a reputable sup­
plier in your Chrysler Corporation vehicle. For most
year-round service, number 2 (two) diesel fuel meet­ ing ASTM specification D-975 will provide good per­
formance. If the vehicle is exposed to extreme cold (below -18°C - 0°F), or for any reason is required to
operate at colder than normal conditions for pro­ longed periods, then dilution of the 2D fuel with 50
percent kerosine or number ID diesel fuel will pro­
vide better protection from fuel gelling or wax-plug­ ging of the fuel filters. Diesel fuel is seldom
completely free of water. To prevent fuel system
trouble, including fuel tube (line) freezing in winter, drain the accumulated water using the drain pro­
vided. If you buy good quality fuel and follow the cold weather advice above, fuel conditioners should
not be required in your vehicle.

Page 822 of 1502




FUEL SYSTEM
14 • 3
FUEL
DELIVERY SYSTEM-EXCEPT DIESEL

INDEX
page
Fuel Filter—3.9L/5.2L Gas Engine
............
10

Fuel
Filter—5.9L
Gas Engine
11
Fuel Pressure Leak Down Test—3.9L/5.2L Engine
. 8

Fuel Pressure Leak Down Test—5.9L Engine
.... 9

Fuel Pump Capacity
Test—All
Gas
Engines
..... 8

Fuel Pump
Control
........................
5

Fuel Pump Module—3.9L/5.2L Engines
3

GENERAL INFORMATION
Two different types
of
fuel delivery/fuel return sys­
tems
are
used.
The
system used with
the
3.9L/5.2L
engine will route excess fuel pressure back
to the

fuel tank through
a
fuel return line.
The
system used
with
the 5.9L
engine will
not
have
a
separate fuel
re­

turn line. This system will
be
referred
to as a re-

turnless type.
The
fuel pump module used with
the
5.9L engine will contain
a
combination fuel pressure
regulator
and
fuel filter. Refer
to the
following Fuel
Pump Module
for
additional information
or,
refer
to

the Multi-Port Fuel Injection sections
of
this Fuel System group. A separate frame mounted fuel filter will
not be

used with
any 5.9L gas
powered engine.

FUEL
PUMP
M0DULE-3.9L/5.2L
ENGINES
The fuel pump module
on
vehicles equipped with
3.9L/5.2L engines
is
installed
in the top of the
fuel
tank (Fig.
1). The
fuel pump module contains
the
fol­ lowing components (Fig.
2):

• Fuel pump
• Fuel pump reservoir

A
separate in-tank fuel filter
• Pressure relief/rollover valve
PRESSURE
RELIEF/
PUMP/GAUGE

Fig.
1
Top View
of
Fuel
Pump
Module—3.9U5.2L
Engine
page
Fuel Pump Module—5.9L Engine
.............
3

Fuel System Pressure Release
...............
5

Fuel System Pressure Test—3.9L/5.2L Engine
... 5
Fuel System Pressure Test—5.9L Engine
7

Fuel Tubes/Lines/Hoses
and
Clamps
..........
11

General
Information
3

Quick-Connect
Fittings
11

• Fuel pump gauge sending unit
• Fuel supply
and
return tube connections
J9114-147

Fig.
2
Fuel
Pump
Module
Components—Typical

FUEL PUMP MODULE—5.9L ENGINE
The fuel pump module
on
vehicles equipped with
a

5.9L
gas
powered engine
is
installed
in the top of
the
fuel tank
(Fig. 3). The
fuel pump module contains
the following components (Fig.
2):
• Fuel filter/fuel pressure regulator
• Fuel pump • Fuel pump reservoir

A
separate in-tank fuel filter
• Pressure relief/rollover valve
• Fuel pump gauge sending unit
• Fuel supply tube connection

Page 823 of 1502


14-4
FUEL
SYSTEM



Fig.
3 Top View of
Fuel
Pump
Module—5.9L
Engine
FUEL
PUMP

The fuel pump used in this system has a perma­
nent magnet electric motor. The pump is part of the
fuel pump module (Fig. 2). The fuel pump module is suspended in fuel in the fuel tank. Fuel is drawn in
through a filter and pushed through the electric mo­
tor to the outlet. The pump contains a check valve.
This valve is located near the pump outlet. It re­ stricts fuel movement in either direction to maintain
fuel supply line pressure when the pump is not oper­ ational. Voltage to operate the pump is supplied
through the auto shut down (ASD) and fuel pump re­
lays.

WARNING:
THE
FUEL SYSTEM
IS
UNDER
A
CON­ STANT PRESSURE (EVEN
WITH
THE
ENGINE OFF).
BEFORE
SERVICING
THE
FUEL PUMP, FUEL

TUBES
(LINES), FUEL FILTER,
OR
FUEL
INJEC­

TOR^),
THE
FUEL SYSTEM PRESSURE MUST
BE
RELEASED.

FUEL
PUMP
REPLACEMENT

The fuel pump is not serviceable. If the fuel pump
needs replacement, the complete fuel pump module must be replaced. Perform the Fuel System Pressure
Release procedure before servicing the fuel pump.

FUEL
PUMP
MODULE
REMOVAL

WARNING:
THE
FUEL SYSTEM
IS
UNDER
A
CON­ STANT PRESSURE (EVEN
WITH
THE
ENGINE OFF).
BEFORE
SERVICING
THE
FUEL PUMP MODULE,
THE FUEL SYSTEM PRESSURE MUST
BE RE­
LEASED.

CAUTION:
Whenever
the
fuel
pump
module
is
ser­
viced,
the
locknut
and gasket
must
be replaced. (1) Drain the fuel tank. Refer to Draining Fuel
Tank in the Fuel Tank section of this group.
(2) Remove fuel tank. Refer to the Fuel Tank sec­
tion of this group.
(3) The fuel pump module locknut is threaded onto
the fuel tank. Remove the fuel pump module locknut
(Figs.
1 or 3). The fuel pump module will spring up
when the locknut is removed.

(4)
Remove module from fuel tank.

DISASSEMBLY-
FUEL GAUGE SENDING
UNIT
(1) Remove sending unit mounting screws (Fig. 4).
(2) Mark the sending unit electrical wires before

FUEL
GAUGE
TABS

IN-TANK

FUEL
FILTER
J9114-146

Fig.
4
Module
Service—Typical
removal for correct installation. Carefully disconnect electrical wires from sending unit. Remove sending unit.
(3) Reverse order of removal for installation.

IN-TANK FUEL FILTER
The in-tank filter is attached to the bottom of the
fuel pump module (Fig. 4).
(1) Pry the mounting tabs back and remove the in-
tank fuel filter.
(2) Install new fuel filter into retaining tabs.

FUEL
PUMP
MODULE
INSTALLATION

CAUTION:
Whenever
the
fuel
pump
module
is
ser­
viced,
the
locknut
and
gasket must
be
replaced.

(1) Using a new gasket, position fuel pump module
into opening in fuel tank. (2) Position new locknut over top of fuel pump
module. (3) Tighten locknut. (4) Install fuel tank. Refer to Fuel Tank Installa­
tion in this section.

Page 824 of 1502




FUEL SYSTEM
14-5
FUEL PUMP CONTROL

The powertrain control module (PCM) computer en­
ergizes the fuel pump through the automatic shut
down (ASD) and fuel pump relays. Battery voltage is applied to the relay from the ignition switch. The coil
in the relay is energized when a ground is provided
by the PCM. The relays are located in the engine compartment (Fig. 5).

DATA
UNK
CONTROL

CONNECTOR
MODULE
J9314-164

Fig.
5
Fuel
Pump
and ASD
Relays

FUEL
SYSTEM
PRESSURE
RELEASE

ALL
GAS
ENGINES
The fuel system is under constant fuel pressure
(even with the engine off).
WARNING: BECAUSE THE FUEL SYSTEM IS UN­ DER CONSTANT FUEL PRESSURE, THIS PRES­
SURE MUST BE RELEASED BEFORE SERVICING
ANY FUEL SUPPLY OR FUEL RETURN SYSTEM COMPONENT. THIS DOES NOT APPLY TO THROT­
TLE BODY REMOVAL.
(1) Disconnect negative battery cable.
(2) Remove the fuel tank filler tube cap to release
fuel tank pressure. (3) Remove protective cap from pressure test port
on the fuel rail (Figs. 6, 7 or 8).
WARNING: DO NOT ALLOW FUEL TO SPILL ONTO
THE ENGINE INTAKE OR EXHAUST MANIFOLDS. PLACE SHOP TOWELS UNDER AND AROUND THE
PRESSURE PORT TO ABSORB FUEL WHEN THE
PRESSURE IS RELEASED FROM THE FUEL RAIL.
WARNING: WEAR PROPER EYE PROTECTION
WHEN RELEASING FUEL SYSTEM PRESSURE.
(4) Obtain the fuel pressure gauge/hose assembly
from fuel pressure gauge tool set 5069. Remove the
gauge from the hose.
CONNECTOR
HOSES
J9214-27

Fig.
7
Fuel
Pressure
Test Port—5.2L (V-8)
Engine
(5) Place one end of hose (gauge end) into an ap­
proved gasoline container. (6) Place a shop towel under the test port.
(7) To release fuel pressure, screw the other end of
hose onto the fuel pressure test port.
(8) After fuel pressure has been released, remove
the hose from the test port. (9) Install protective cap to fuel test port.

FUEL SYSTEM
PRESSURE
TEST-3.9L/5.2L

ENGINE
Fuel systems on vehicles equipped with a 3.9L or

Page 825 of 1502


14-6 FUEL
SYSTEM



I
l /////

PROTECTIVE
CAP AND
TEST
PORT

J9314-168

Fig.
8
Fuel
Pressure
Test Port—5.9L (V-8)
Engine
5.2L engine are equipped with a vacuum assisted
fuel pressure regulator (Figs. 6 or 7). With engine at
idle speed, system fuel pressure should be approxi­
mately 214 kPa (31 psi) with the vacuum line con­
nected to the regulator. With the vacuum line
disconnected from the regulator, fuel pressure should
be approximately 269 kPa (39 psi). This is 55-69 kPa (8-10 psi) higher.
(1) Remove the protective cap at the fuel rail (Figs.
6 or 7). Connect the 0-414 kPa (0-60 psi) fuel pres­
sure gauge (from Gauge Set 5069) to test port pres­
sure fitting on fuel rail (Fig. 9).

FUEL
PRESSURE
TEST GAUGE

J9214-28

Fig.
9
Fuel
Pressure
Test—
Typical

(2) Note pressure gauge reading. Fuel pressure
should be approximately 214 kPa (31 psi) at idle. (3) Disconnect vacuum line at fuel pressure regu­
lator (Figs. 6 or 7). Note gauge reading. With vac­ uum line disconnected, fuel pressure should rise to
approximately 269 kPa (39 psi).
Fuel pressure should be approximately 55-69 kPa
(8-10 psi) higher with vacuum line removed from
regulator. If not, inspect pressure regulator vacuum line for leaks, kinks or blockage. If vacuum line
checks OK and fuel pressure does not rise approxi­
mately 8-10 psi after disconnecting vacuum line, re­
place fuel pressure regulator.
The fuel pressure regulator is not adjustable. (4) If fuel pressure exceeds 45 psi, check fuel re­
turn line for kinks or obstructions. If the previous tests checked good, fuel pump pres­
sure is correct. If pump pressure was low, proceed as
follows:
(5) Release fuel system pressure. Refer to the pre­
vious Fuel Pressure Release Procedure in this group. (6) Disconnect the 5/16 inch fuel return line quick-
connect fitting (Fig. 10) on fuel rail near fuel pres­
sure regulator. Connect Fuel Line (Tube) Pressure
Test Adapter Tool number 6539 (5/16 in.) between
the disconnected fuel return tube and fuel rail (Fig.
11).
FUEL TUBE REMOVAL
QUICK CONNECT

FITTING

PUSH
INSTALLATION
X
PUSH-

/
PUSH
PLASTIC
RETAINER
J9314-100

Fig.
10
Removing
Quick-Connect
Fitting

WARNING:
THE
FUEL SYSTEM
PRESSURE
IN THE
FOLLOWING TEST
MAY
EXCEED
100
PSI.
BEFORE
STARTING TEST, VERIFY GOOD CONNECTIONS
AT

ENDS
OF
ADAPTER TOOL
6539.
BE
SURE TOOL
IS

LOCKED
ONTO FUEL RAIL
AND
FUEL RETURN

LINE.
PULL FIRMLY
ON
ENDS
OF
TOOL
TO
VER­
IFY.

(7) To activate the fuel pump and pressurize the
system, obtain the DRB II scan tool. Refer to the ap-

Page 826 of 1502




FUEL
SYSTEM
14 - 7

Fig.
1"f
Adapter Tool—Typical
Connection
propriate Powertrain Diagnostic Procedures service
manual for DRB II operation.
(8) MOMENTARILY pinch the rubber hose por­
tion of adapter tool 6539. Pressure should rise to ap­
proximately 75 psi within two (2) seconds. DO NOT
pinch hose for longer than five seconds.
If fuel pump pressure rises to approximately 75 psi
within two seconds, pump is operating at its maxi­ mum and is correct. If fuel pump pressure does not rise to approxi­
mately 75 psi within two seconds, proceed as follows:
(9) Release fuel system pressure. Refer to the pre­
vious Fuel Pressure Release Procedure in this group. (10) Raise and support vehicle.
(11) Disconnect fuel supply line at inlet (fuel tank
side) of fuel filter. Connect Fuel Line (Tube) Pressure
Test Adapter Tool number 6631 (3/8 in.) between fuel
filter and fuel supply line.

WARNING:
THE
FUEL SYSTEM
PRESSURE
IN THE
FOLLOWING TEST MAY EXCEED
100
PSI. BEFORE
STARTING TEST, VERIFY GOOD CONNECTIONS
AT
ENDS
OF
ADAPTER TOOL 6631.
BE
SURE TOOL
IS

LOCKED
ONTO FUEL FILTER
AND
FUEL SUPPLY

LINE.
PULL FIRMLY
ON
ENDS
OF
TOOL
TO
VER­
IFY.

(12) To activate the fuel pump and pressurize the
system, obtain the DRB II scan tool. Refer to the ap­
propriate Powertrain Diagnostic Procedures service manual for DRB II operation.
MOMENTARILY pinch the rubber hose portion of
adapter tool 6631. Pressure should rise to approxi­
mately 75 psi within two (2) seconds. DO NOT pinch
hose for longer than five seconds.
If fuel pump pressure now rises to approximately
75 psi within two seconds, but this pressure could not
be met at the fuel rail, check for a plugged or re­ stricted fuel filter. Also check the fuel supply line be­ tween fuel filter and fuel rail for kinks or
obstructions. Proceed to the Fuel Pump Capacity
Test.

FUEL
SYSTEM PRESSURE
TEST—5.9L
ENGINE
Fuel systems on vehicles equipped with a 5.9L en­
gine are equipped with a fuel tank module mounted,
combination fuel filter/fuel pressure regulator (Fig.
12).
The fuel pressure regulator is not controlled by
engine vacuum.

ROLLOVER VALVE J9314-167 Fig.
12
Fuel
Filter/Fuel
Pressure
Regulator—5.9L
Engine

With engine at idle speed, system fuel pressure
should be approximately 241-310 kPa (35-45 psi). (1) Remove the protective cap at the fuel rail (Fig.

13).
Connect the 0-414 kPa (0-60 psi) fuel pressure
gauge (from Gauge Set 5069) to test port pressure fit­
ting on fuel rail (Fig. 14).

Fig.
13
Fuel
Pressure
Test Port—5.9L
Engines

(2) Note pressure gauge reading. Fuel pressure
should be approximately 241-310 kPa (35-45 psi) at

idle.

Page 827 of 1502


Fig.
14
Fuel
Pressure
Test—Typical
(3) If pressure is at O psi, connect DRB II scan tool
and refer to operating instructions in the appropriate
Powertrain Diagnostics Procedures service manual. If operating pressure is above 45 psi, fuel pump is
OK. Replace fuel filter/fuel pressure regulator assem-
bly.

FUEL
PUMP CAPACITY TEST-ALL GAS ENGINES
Before performing this test, verify fuel pump pres­
sure by performing the previous tests. (1) Release the fuel system pressure from fuel sys­
tem. Refer to the previous Fuel Pressure Release
Procedure in this group. (2) Disconnect the fuel supply line at fuel rail near
pressure regulator. (3) Connect Fuel Line (Tube) Pressure Test
Adapter Tool number 6631 (3/8 in.) into the discon­ nected fuel supply line (tube). Insert the other end of
Adapter Tool 6631 into an approved gasoline con­
tainer.
(4)
To activate the fuel pump and pressurize the
system, obtain the DRB II scan tool. Refer to the ap­
propriate Powertrain Diagnostic Procedures service manual for DRB II operation. (5) 3.9L/5.2L Engines: A good fuel pump will de­
liver approximately 1 liter of fuel per minute. 5.9L
Engines: A good fuel pump will deliver approxi­
mately 2 liters of fuel per minute.

FUEL
PRESSURE
LEAK DOWN
TEST-3
JL/5.2L

ENGINE

ENGINE
OFF Abnormally long periods of cranking to restart a
hot engine that has been shut down for a short pe­ riod of time may be caused by:
• Fuel pressure bleeding past the fuel pressure reg­
ulator.
• Fuel pressure bleeding past the check valve in the
outlet end of the fuel tank mounted fuel pump. (1) Remove protective cap at fuel rail test port

(Figs.
15 or 16). With the engine off, connect an ac­
curate 0-689 kPa (0-100 psi) fuel gauge to the pres­
sure test port fitting on the fuel rail. The fitting on
the pressure tester must be in good condition and
free of any leaks before performing this test.
PRESSURE
REGULATOR

CONNECTOR
HOSES
J9214-27

Fig.
16
Fuel
Pressure
Test Port—5.2L
Engine

Page 828 of 1502




FUEL
SYSTEM
14 - 9 (2) Start the vehicle and let engine idle. Check
fuel pressure reading on gauge. Fuel pressure should
be within specifications. Refer to the previous Fuel System Pressure Tests.
(3) Shut engine off. Observe and record fuel pres­
sure reading on gauge. Leave fuel pressure gauge
connected. Allow engine to set for 30 minutes and
then compare the fuel pressure reading on the gauge
with the reading taken when engine was shut down.
A pressure drop of up to 138 kPa (20 psi) within 30 minutes is within specifications.
(4) If the fuel pressure drop is within specifica­

tions,
the fuel pump outlet check valve and fuel pres­ sure regulator are both operating normally.

(5)
If fuel pressure drop is greater than 138 kPa
(20 psi), it must be determined if this drop is being
caused by (in-tank mounted) fuel pump outlet check
valve or fuel pressure regulator. Proceed to next step. (6) Release the fuel system pressure from fuel sys­
tem. Refer to the previous Fuel Pressure Release
Procedure in this group. (7) Disconnect both fuel tubes (lines) at fuel rail
near fuel pressure regulator. (8) Connect Fuel Line (Tube) Pressure Test
Adapter Tool number 6631 (3/8 in.) between the dis­ connected fuel supply line and fuel rail (Fig. 17). (9) Connect Fuel Line (Tube) Pressure Test
Adapter Tool number 6539 (5/16 in.) between the dis­
connected fuel return line and fuel rail (Fig. 17).
Fig. 17 Adapter Tools—Typical Connections
(10) Start engine. Observe and record fuel system
pressure.
(11) Shut engine off.
(12) Clamp off the rubber hose portion of adapter
tool number 6539 connected to the fuel return line.
Allow engine to set for 30 minutes. If pressure has
dropped more than 138 kPa (20 psi) in 30 minutes,
pressure is bleeding past the (in-tank mounted) fuel pump outlet check valve. Replace Fuel Pump Module assembly. Refer to Fuel Pump Module removal and installation in this group. If pressure drop is within
specifications, proceed to next step.
(13) Clamp off the rubber hose portion of adapter
tool number 6631 connected to the fuel supply line.
Allow engine to set for 30 minutes. If pressure has
dropped more than 138 kPa (20 psi) in 30 minutes,
pressure is bleeding past the fuel pressure regulator.
Replace fuel pressure regulator. Refer to Fuel Pres­ sure Regulator removal and installation in the Com­
ponent Removal/Installation section of this group.

FUEL
PRESSURE
LEAK DOWN TEST—5.9L

ENGINE

ENGINE OFF Abnormally long periods of cranking to restart a
hot engine that has been shut down for a short pe­
riod of time may be caused by:
• Fuel pressure bleeding past a fuel injector.
• Fuel pressure bleeding past the check valve in the
fuel filter/fuel pressure regulator.
(1) Disconnect the fuel inlet tube at fuel rail (Fig.

18).
This is done by pushing on plastic part of quick-
connect fitting on tube (Fig. 19).
Fig. 18 Fuel Pressure Test Port—5.9L Engines
(2) Connect Fuel Line (Tube) Pressure Test
Adapter Tool number 6539 (5/16 in.) between the dis­
connected fuel tube and fuel rail.
(3) Connect the 0-414 kPa (0-60 psi) fuel pressure
test gauge (from Gauge Set 5069) to the test port on
tool 6631. The fittings on both tools must be in good condition and free from any small leaks
before performing the proceeding test,
(4) Start engine and bring to normal operating
temperature.
(5) Observe test gauge. Normal operating pressure
should be 241-310 kPa (35-45 psi). (6) Shut engine off.
(7) Pressure should not fall below 24 psi for five
minutes.

Page 829 of 1502


FUEL
TUBE

REMOVAL

QUICK
CONNECT

FITTING

PUSH
PUSH PUSH

INSTALLATION

X
PUSH

/

•PUSH

PLASTIC

RETAINER
J9314-100

Fig. 19 Removing/Installing Quick-Connect Fitting (8) If pressure falls below 24 psi, it must deter­
mined if a fuel injector, the fuel module mounted fuel
pressure regulator or a fuel tube/line is leaking. (9) Again, start engine and bring to normal oper­
ating temperature.
(10) Shut engine off.
(11) Checking for fuel injector leakage: Clamp
off the rubber hose portion of tool 6539 between the
disconnected fuel tube (line) and test port inlet. If
pressure now holds at or above 24 psi, a fuel injector or the fuel rail is leaking.
Checking for fuel pressure regulator or fuel
tube leakage: Clamp off the rubber hose portion of
tool 6539 between the fuel rail and test port inlet. If
pressure now holds at or above 24 psi, a leak can be
found at a fuel tube/line. If no leaks are found at fuel

tubes,
replace the fuel filter/fuel pressure regulator.

MECHANICAL MALFUNCTIONS
Mechanical malfunctions are more difficult to diag­
nose with this system. The powertrain control mod­
ule (PCM) has been programmed to compensate for
some mechanical malfunctions such as incorrect cam
timing, vacuum leaks, etc. If engine performance
problems are encountered and a diagnostic trouble code (DTC) is not displayed, the problem may be me­
chanical rather than electronic.

FUEL FILTER-3.9L/5.2L GAS ENGINE
For diesel engines, refer to Fuel/Water Separator
Filter in the Diesel Fuel Injection—Service Proce­
dures section of this group.
REMOVAL

WARNING:
THE
FUEL
SYSTEM
IS
UNDER
A
CON­
STANT
PRESSURE
(EVEN
WITH
THE
ENGINE
OFF).
BEFORE
SERVICING
THE
FUEL FILTER,
THE
FUEL
SYSTEM
PRESSURE
MUST
BE
RELEASED.

The fuel filter is located under the vehicle and near
the fuel tank. It is mounted to the frame rail (Fig.
20). (1) Perform Fuel System Pressure Release proce­

dure.
(2) Disconnect negative battery cable from battery.
(3) Raise and support vehicle.
(4) Remove and discard both fuel hose-to-fuel filter
hose clamps. (5) Wrap a shop towel around hoses to absorb fuel.
Remove hoses at filter. (6) Remove filter from frame.
FUEL
HOSES
HOSE
CLAMPS
.
FILTER
MOUNTING
BOLT
FUEL

FILTER

J9214-68

Fig.
20
Fuel
Filter—3.9U5.2L
Engine

INSTALLATION

CAUTION:
The
tubes/hoses used
on
fuel
injected

vehicles
are of a
special construction. This
is due

to
the
higher
fuel
pressures
and the
possibility
of
contaminated
fuel
in
this system.
If it is
necessary
to replace these tubes/hoses, only tubes/hoses marked EFM/EFI
may be
used.

CAUTION:
The
hose clamps used
on
fuel
injected

vehicles
are of a
special rolled edge construction
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.

(1) Install fuel filter to frame rail. Tighten mount­
ing bolt to 8 N»m (75 in. lbs.) torque. (2) Install new original equipment clamps to fuel

hoses.

Page 830 of 1502




FUEL SYSTEM
14-11 (3)
Install hoses
to
filter. Tighten clamps
to 1 N*m
(10 in. lbs.)
torque. (4) Lower vehicle.

(5)
Connect battery cable
to
battery.
(6) Start engine
and
check
for
leaks.

FUEL
FILTER—5.9L
GAS ENGINE
For diesel engines, refer
to
Fuel/Water Separator
Filter
in the
Diesel Fuel Injection—Service Proce­
dures section
of
this group. The fuel filter
and
fuel pressure regulator
(Fig. 21)

are
one
non-repairable component.
For
service, refer
to Fuel Filter/Fuel Pressure Regulator. This
can be

found
in the
Multi-Port Fuel Injection (MPI)—Com­
ponent Removal/Installation section
of
this group.

ROLLOVER VALVE
J9314-167
Fig.
21
Fuel Filter/Fuel Pressure Regulator—5.9L Engine

FUEL
TUBES/LINES/HOSES
AND CLAMPS
Also refer
to
Quick-Connect Fittings
in
this sec­
tion.

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
PRESSURE
RELEASE
PROCEDURE
IN
THIS

GROUP.

Inspect
all
hose connections such
as
clamps, cou­
plings
and
fittings
to
make sure they
are
secure
and
leaks
are not
present.
The
component should
be re­

placed immediately
if
there
is any
evidence
of
degra­ dation that could result
in
failure.
Avoid contact
of any
fuel tubes/hoses with other
ve­

hicle components that could cause abrasions
or scuff­
ing.
Be
sure that
the
plastic fuel tubes
are
properly
routed
to
prevent pinching
and to
avoid heat sources.

CAUTION:
The
tubes/hoses used
on
fuel
injected

vehicles
are of a
special construction. This
is due
to
the
higher
fuel
pressures
and the
possibility
of

contaminated
fuel
in
this system.
If it is
necessary
to replace these tubes/hoses, only tubes/hoses marked EFM/EFI
may
be
used.

CAUTION:
The
hose clamps used
on
fuel
injected

vehicles
are of a
special rolled edge construction
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.
Tighten hose clamps
to 1 N*m (10 in. lbs.)
torque.

QUICK-CONNECT FITTINGS
Also refer
to the
previous Fuel Tubes/Lines/Hoses
and Clamps. Two different types
of
Quick-Connect fittings
are

used
at
several fuel system connections.
One
type
of

fitting will
be
referred
to as a Tab
Type Fitting.
The

other will
be
referred
to as a
Plastic Ring Type fit­
ting.

CAUTION:
Quick-connect fittings
are not
serviced
separately.
Do not
attempt
to
repair damaged quick-
connect fittings
or
fuel
tubes. Replace
the
complete

fuel
tube/quick-connect
fitting
assembly.
TAB
TYPE
FITTING This fitting
is
equipped with
a
retainer
tab
(Figs.

22
or
23) that must
be
released prior
to
disconnecting
the fitting from
the
fuel tube. This type
of
fitting
can

be disassembled either manually
or
with
a
straight
blade screwdriver.
TUBE
END TAB
J9114-167

Fig.
22 Tab
Type
Fitting

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