sensor DODGE RAM 2001 Service Repair Manual

FUEL SYSTEM
TABLE OF CONTENTS
page page
FUEL DELIVERY - GASOLINE................1
FUEL INJECTION - GASOLINE..............28FUEL DELIVERY - DIESEL.................54
FUEL INJECTION - DIESEL.................87
FUEL DELIVERY - GASOLINE
TABLE OF CONTENTS
page page
FUEL DELIVERY - GASOLINE
DESCRIPTION............................2
OPERATION.............................2
DIAGNOSIS AND TESTING..................2
FUEL PRESSURE LEAK DOWN TEST........2
STANDARD PROCEDURE...................3
FUEL SYSTEM PRESSURE RELEASE
PROCEDURE...........................3
SPECIFICATIONS.........................4
SPECIAL TOOLS..........................4
FUEL FILTER/PRESSURE REGULATOR
DESCRIPTION............................5
OPERATION.............................5
REMOVAL...............................5
INSTALLATION............................6
FUEL LEVEL SENDING UNIT / SENSOR
DESCRIPTION............................7
OPERATION.............................7
DIAGNOSIS AND TESTING..................8
FUEL GAUGE SENDING UNIT..............8
REMOVAL...............................8
INSTALLATION............................9
FUEL LINES
DESCRIPTION............................9
FUEL PUMP
DESCRIPTION............................9
OPERATION.............................9
DIAGNOSIS AND TESTING..................9
FUEL PUMP CAPACITY TEST..............9FUEL PUMP PRESSURE TEST............10
FUEL PUMP AMPERAGE TEST............10
FUEL PUMP MODULE
DESCRIPTION...........................12
OPERATION.............................13
REMOVAL..............................13
INSTALLATION...........................13
FUEL RAIL
DESCRIPTION...........................15
OPERATION.............................15
REMOVAL..............................16
INSTALLATION...........................18
FUEL TANK
DESCRIPTION...........................19
OPERATION.............................19
REMOVAL..............................19
INSTALLATION...........................20
INLET FILTER
REMOVAL..............................22
INSTALLATION...........................22
QUICK CONNECT FITTING
DESCRIPTION...........................22
STANDARD PROCEDURE..................22
QUICK-CONNECT FITTINGS..............22
ROLLOVER VALVE
DESCRIPTION...........................25
REMOVAL..............................26
INSTALLATION...........................27
BR/BEFUEL SYSTEM 14 - 1

FUEL DELIVERY - GASOLINE
DESCRIPTION - FUEL DELIVERY SYSTEM
The fuel delivery system consists of:
²the fuel pump module containing the electric
fuel pump, fuel filter/fuel pressure regulator, rollover
valve (certain modules), fuel gauge sending unit (fuel
level sensor) and a separate fuel filter located at bot-
tom of pump module
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 - FUEL DELIVERY SYSTEM
Fuel is returned through the fuel pump module
and back into the fuel tank through the fuel filter/
fuel pressure regulator. A separate fuel return line
from the engine to the tank is not used with any gas-
oline powered engine.
The fuel tank assembly consists of: the fuel tank,
fuel pump module assembly, fuel pump module lock-
nut/gasket and rollover valve(s) (refer to 25, Emis-
sion Control System for rollover 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 25, 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. Afterthe 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.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.
(1) Disconnect the fuel inlet line at fuel rail. Refer
to Fuel Tubes/Lines/Hoses and Clamps for proce-
dures. On some engines, air cleaner housing removal
may be necessary before fuel line disconnection.
(2) 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.
(3) Connect correct Fuel Line Pressure Test
Adapter Tool Hose between disconnected fuel line
and fuel rail (Fig. 1).
Fig. 1 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
14 - 2 FUEL DELIVERY - GASOLINEBR/BE

SPECIFICATIONS
SPECIFICATIONS - FUEL SYSTEM PRESSURE -
GAS ENGINES
All Gasoline Powered Engines:339 kPa634
kPa (49.2 psi65 psi)
SPECIFICATIONS - TORQUE - FUEL DELIVERY
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Fuel Pump Module
Locknut24-44 18-32
Fuel Rail Mounting
BoltsÐ3.9L/5.2L/5.9L
Engines23 200
Fuel Rail Mounting
BoltsÐ8.0L Engine15 136
Fuel Tank Mounting Nuts 41 30
Fuel Hose Clamps 1 15
SPECIAL TOOLS
FUEL SYSTEM
Spanner WrenchÐ6856
Fitting, Air MeteringÐ6714
Adapters, Fuel Pressure TestÐ6539 and/or 6631
O2S (Oxygen Sensor) Remover/InstallerÐC-4907
14 - 4 FUEL DELIVERY - GASOLINEBR/BE
FUEL DELIVERY - GASOLINE (Continued)

(4) Press filter/regulator (by hand) into rubber
grommet. The assembly should be pointed towards
drivers side of vehicle (Fig. 4) or (Fig. 5).
(5) Install fuel tank. Refer to Fuel Tank Removal/
Installation.
(6) Check for fuel leaks.
FUEL LEVEL SENDING UNIT /
SENSOR
DESCRIPTION
The fuel gauge sending unit (fuel level sensor) is
attached to the side of the fuel pump module. The
sending unit consists of a float, an arm, and a vari-
able resistor track (card).
OPERATION
The fuel pump module has 4 different circuits
(wires). Two of these circuits are used for the fuel
gauge sending unit for fuel gauge operation, and for
certain OBD II emission requirements. The other 2
wires are used for electric fuel pump operation.
For Fuel Gauge Operation:A constant current
source of about 32 mA is supplied to the resistor
track on the fuel gauge sending unit. This is fed
directly from the Powertrain Control Module (PCM).
The resistor track is used to vary the voltage depend-
ing on fuel tank float level. As fuel level increases,
the float and arm move up, which decreases voltage.
As fuel level decreases, the float and arm move
down, which increases voltage. The varied voltage
signal is returned back to the PCM through the sen-
sor return circuit. Output voltages will vary from
about .6 volts at FULL, to about 8.6 volts at EMPTY
(Jeep models), or, about 7.0 volts at EMPTY (Dodge
Truck models).NOTE: For diagnostic purposes,
this voltage can only be verified with the fuel
gauge sending unit circuit closed (i.e. having all
of the sending units electrical connectors con-
nected).
Fig. 6 Filter/Regulator Removal and InstallationÐ
TYPICAL
1 - RUBBER GROMMET
2 - FUEL FILTER/FUEL PRESSURE REGULATOR
Fig. 7 Fuel Tube and ClampÐTYPICAL
1 - FUEL FILTER/FUEL PRESSURE REGULATOR
2 - TUBE CLAMP
3 - FUEL TUBE
Fig. 8 Tightening Fuel Tube ClampÐTYPICAL
1 - TOOL C-4124
2 - TUBE CLAMP
3 - FUEL TUBE
BR/BEFUEL DELIVERY - GASOLINE 14 - 7
FUEL FILTER/PRESSURE REGULATOR (Continued)

Both of the electrical circuits between the fuel
gauge sending unit and the PCM are hard-wired (not
multi-plexed). After the voltage signal is sent from
the resistor track, and back to the PCM, the PCM
will interpret the resistance (voltage) data and send
a message across the multi-plex bus circuits to the
instrument panel cluster. Here it is translated into
the appropriate fuel gauge level reading. Refer to
Instrument Panel for additional information.
For OBD II Emission Monitor Requirements:
The PCM will monitor the voltage output sent from
the resistor track on the sending unit to indicate fuel
level. The purpose of this feature is to prevent the
OBD II system from recording/setting false misfire
and fuel system monitor diagnostic trouble codes.
The feature is activated if the fuel level in the tank
is less than approximately 15 percent of its rated
capacity. If equipped with a Leak Detection Pump
(EVAP system monitor), this feature will also be acti-
vated if the fuel level in the tank is more than
approximately 85 percent of its rated capacity.
DIAGNOSIS AND TESTING - FUEL GAUGE
SENDING UNIT
The fuel gauge sending unit contains a variable
resistor (track). As the float moves up or down, elec-
trical resistance will change. Refer to 8, Instrument
Panel and Gauges for Fuel Gauge testing. To test the
gauge sending unit only, it must be removed from
vehicle. The unit is part of the fuel pump module.
Refer to Fuel Pump Module Removal/Installation for
procedures. Measure the resistance across the send-
ing unit terminals. With float in up position, resis-
tance should be 20 ohms66 ohms. With float in
down position, resistance should be 220 ohms66
ohms.
REMOVAL
The fuel gauge sending unit (fuel level sensor) and
float assembly is located on the side of fuel pump
module (Fig. 9). The fuel pump module is located
inside of fuel tank.
(1) Remove fuel tank. Refer to Fuel Tank±All
Engines in the Removal/Installation section.
(2) Remove fuel pump module. Refer to Fuel Pump
Module Removal/Installation.
(3) Unplug 4±way electrical connector (Fig. 9).
(4) Disconnect 2 sending unit wires at 4±way con-
nector. The locking collar of connector must be
removed before wires can be released from connector.
Note location of wires within 4±way connector.
(5) The sending unit is retained to pump module
with a small lock tab and notch (Fig. 10). Carefully
push lock tab to the side and away from notch while
sliding sending unit downward on tracks for removal.
Note wire routing while removing unit from module.
Fig. 9 Fuel Gauge Sending Unit LocationÐTYPICAL
Module
1 - FUEL FILTER/PRESSURE REGULATOR
2 - ELECTRICAL CONNECTOR
3 - ELECTRIC FUEL PUMP
4 - FUEL GAUGE FLOAT
5 - FUEL PUMP INLET FILTER
6 - FUEL GAUGE SENDING UNIT
7 - MODULE LOCK TABS (3)
Fig. 10 Fuel Gauge Sending Unit Lock Tab/Tracks
1 - FUEL GAUGE SENDING UNIT
2 - LOCK TAB
3 - NOTCH
4 - TRACKS
14 - 8 FUEL DELIVERY - GASOLINEBR/BE
FUEL LEVEL SENDING UNIT / SENSOR (Continued)

INSTALLATION
The fuel gauge sending unit (fuel level sensor) and
float assembly is located on the side of fuel pump
module (Fig. 9). The fuel pump module is located
inside of fuel tank.
(1) Position sending unit into tracks. Note wire
routing.
(2) Push unit on tracks until lock tab snaps into
notch.
(3) Connect 2 sending unit wires into 4±way con-
nector and install locking collar.
(4) Connect 4±way electrical connector to module.
(5) Install fuel pump module. Refer to Fuel Pump
Module Removal/Installation.
(6) Install fuel tank. Refer to Fuel Tank±All
Engines in the Removal/Installation section.
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, FIT-
TINGS OR LINES, THE FUEL SYSTEM PRESSURE
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 fuel pump is located inside of the fuel pump
module. A 12 volt, permanent magnet, electric motor
powers the fuel pump.
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.
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 graduated 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.
BR/BEFUEL DELIVERY - GASOLINE 14 - 9
FUEL LEVEL SENDING UNIT / SENSOR (Continued)

(17) When LCS adapter test leads are attached
into relay cavities, fuel pumpwill be activated.
Determine fuel pump amperage on DRB screen.
Amperage should be below 10.0 amps. If amperage is
below 10.0 amps, and specifications for the Fuel
Pump Pressure, Fuel Pump Capacity and Fuel Pres-
sure Leak Down tests were met, the fuel pump mod-
ule is OK.
(18) If amperage is more than 10.0 amps, replace
fuel pump module assembly. The electric fuel pump
is not serviced separately.
(19) Disconnect test leads from relay cavities
immediately after testing.
FUEL PUMP MODULE
DESCRIPTION
The fuel pump module on all gas powered engines
is installed in the top of the fuel tank (Fig. 16) or
(Fig. 17). The fuel pump module (Fig. 16), (Fig. 17)or
(Fig. 18)contains the following:
²A combination fuel filter/fuel pressure regulator
²Electric fuel pump
²Fuel pump reservoir
²A separate in-tank fuel filter (at bottom of mod-
ule)²Rollover valve (certain modules)
²Fuel gauge sending unit (fuel level sensor)
²Fuel supply line connection at filter/regulator
²A threaded locknut retaining pump module to
fuel tank
²A gasket between tank flange and module
²Auxiliary non-pressurized fuel supply fitting (not
all engines)
The fuel gauge sending unit (fuel level sensor), and
pick-up filter (at bottom of module) may be serviced
separately. If the electrical fuel pump requires ser-
vice, the entire fuel pump module must be replaced.
The fuel filter/fuel pressure regulator may be ser-
viced separately. Refer to Fuel Filter/Fuel Pressure
Regulator Removal/Installation for additional infor-
mation.
Fig. 15 FUEL PUMP RELAY - TYPE 3
TERMINAL LEGEND
NUMBER IDENTIFICATION
1 COIL BATTERY
2 COIL GROUND
3 COMMON FEED
4 NORMALLY CLOSED
5 NORMALLY OPEN
Fig. 16 Fuel Pump Module - Gas Powered With 26
or 34 Gallon Tank±Typical
1 - FUEL FILTER/PRESSURE REGULATOR
2 - FUEL SUPPLY FITTING
3 - REAR ROLLOVER VALVE
4 - ELECTRICAL CONNECTOR
5 - FUEL PUMP MODULE
6 - FRONT ROLLOVER VALVE
7 - LOCKNUT
14 - 12 FUEL DELIVERY - GASOLINEBR/BE
FUEL PUMP (Continued)

(7) 3.9L (V-6) engine only: Disconnect electrical
connector at intake manifold air temperature sensor.
Do not remove sensor.
(8) Disconnect fuel tube (line) at side of fuel rail.
Refer to Quick-Connect Fittings for procedures,
(9) Remove the remaining fuel rail mounting bolts.
(10) Gently rock and pull theleftfuel rail until
the fuel injectors just start to clear the intake mani-
fold. Gently rock and pull therightfuel rail until
the fuel injectors just start to clear the intake mani-
fold. Repeat this procedure (left/right) until all fuel
injectors have cleared the intake manifold.
(11) Remove fuel rail (with injectors attached)
from engine.
(12) Remove the clip(s) retaining the injector(s) to
fuel rail (Fig. 30) or (Fig. 31).
REMOVAL - 8.0L
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE EVEN WITH THE ENGINE OFF.
BEFORE SERVICING FUEL RAIL, FUEL SYSTEM
PRESSURE MUST BE RELEASED.
(1) Remove negative battery cable at battery.
(2) Remove air cleaner housing and tube.
(3) Perform fuel pressure release procedure. Refer
to Fuel Delivery System section of this group.
(4) Disconnect throttle body linkage and remove
throttle body from intake manifold. Refer to Throttle
Body removal in this group.
(5) Remove ignition coil pack and bracket assem-
bly (Fig. 32) at intake manifold and right engine
valve cover (four bolts).
(6) Remove upper half of intake manifold. Refer to
Engines for procedures.
Fig. 30 Fuel Injector MountingÐTypical
1 - CLIP
2 - INJECTOR
3 - FUEL RAIL
Fig. 31 Injector Retaining ClipsÐTypical Injector
1 - PLIERS
2 - INJECTOR CLIP
3 - FUEL INJECTOR
4 - FUEL RAIL
Fig. 32 Ignition Coil Pack and Mounting BracketÐ
8.0L V-10 Engine
1 - COIL PACKS AND BRACKET
2 - MOUNTING BOLTS (4)
BR/BEFUEL DELIVERY - GASOLINE 14 - 17
FUEL RAIL (Continued)

(7) Disconnect electrical connectors at all fuel
injectors. To remove connector refer to (Fig. 33). Push
red colored slider away from injector (1). While push-
ing slider, depress tab (2) and remove connector (3)
from injector. The factory fuel injection wiring har-
ness is numerically tagged (INJ 1, INJ 2, etc.) for
injector position identification.
(8) Disconnect fuel line quick-connect fitting at
left-rear end of fuel rail. A special 3/8 inch fuel line
disconnection tool will be necessary.
(9) Remove the six fuel rail mounting bolts from
the lower half of intake manifold (Fig. 34).
(10) Gently rock and pull theleftfuel rail until
the fuel injectors just start to clear the intake mani-
fold. Gently rock and pull therightfuel rail until
the fuel injectors just start to clear the intake mani-
fold. Repeat this procedure (left/right) until all fuel
injectors have cleared the intake manifold.
(11) Remove fuel rail (with injectors attached)
from engine.
(12) Remove the clip(s) retaining the injector(s) to
fuel rail (Fig. 30) or (Fig. 31).
INSTALLATION - 3.9L/5.2L/5.9L
(1) Apply a small amount of engine oil to each fuel
injector o-ring. This will help in fuel rail installation.
(2) Install injector(s) and injector clip(s) to fuel
rail.
(3) Position the fuel rail/fuel injector assembly to
the injector openings on the intake manifold.(4) Guide each injector into the intake manifold.
Be careful not to tear the injector o-ring.
(5) Push therightfuel rail down until fuel injec-
tors have bottomed on injector shoulder. Push the
leftfuel rail down until fuel injectors have bottomed
on injector shoulder.
(6) Install fuel rail mounting bolts.
(7) Connect electrical connector to intake manifold
air temperature sensor.
(8) Connect electrical connectors at all fuel injec-
tors. To install connector, refer to (Fig. 29). Push con-
nector onto injector (1) and then push and lock red
colored slider (2). Verify connector is locked to injec-
tor by lightly tugging on connector.
(9) Install the A/C support bracket (if equipped).
(10) Install throttle body to intake manifold. Refer
to Throttle Body installation in this section of the
group.
(11) Install fuel tube (line) at side of fuel rail.
Refer to Quick-Connect Fittings for procedures.
(12) Install air cleaner.
(13) Connect battery cable to battery.
(14) Start engine and check for leaks.
Fig. 33 Remove/Install Fuel Injector Connector
Fig. 34 Fuel Rail Mounting BoltsÐ8.0L V-10
EngineÐTypical
1 - FUEL RAIL
2 - ELECTRICAL CONNECTOR
3 - MOUNTING BOLTS (6)
4 - INTAKE MANIFOLD LOWER HALF
5 - FUEL PRESSURE TEST PORT
6 - FUEL INJECTORS (10)
14 - 18 FUEL DELIVERY - GASOLINEBR/BE
FUEL RAIL (Continued)

FUEL INJECTION - GASOLINE
TABLE OF CONTENTS
page page
FUEL INJECTION - GASOLINE
DIAGNOSIS AND TESTING.................28
VISUAL INSPECTION - 3.9L/5.2L/5.9L
ENGINES.............................28
VISUAL INSPECTION - 8.0L ENGINE........32
SPECIFICATIONS........................35
SPECIAL TOOLS.........................36
ACCELERATOR PEDAL
REMOVAL..............................37
INSTALLATION...........................37
CRANKSHAFT POSITION SENSOR
DESCRIPTION...........................38
OPERATION.............................38
REMOVAL..............................39
INSTALLATION...........................40
FUEL PUMP RELAY
DESCRIPTION...........................41
OPERATION.............................41
REMOVAL..............................41
INSTALLATION...........................41
IDLE AIR CONTROL MOTOR
DESCRIPTION...........................41
OPERATION.............................41
REMOVAL..............................42
INSTALLATION...........................42
INTAKE AIR TEMPERATURE SENSOR
DESCRIPTION...........................43
OPERATION.............................43
REMOVAL..............................43
INSTALLATION...........................43
MANIFOLD ABSOLUTE PRESSURE SENSOR
DESCRIPTION...........................44OPERATION.............................44
REMOVAL..............................45
INSTALLATION...........................45
O2 SENSOR
DESCRIPTION...........................46
OPERATION.............................46
REMOVAL..............................47
INSTALLATION...........................48
PTO SWITCH
DESCRIPTION...........................48
OPERATION.............................48
THROTTLE BODY
DESCRIPTION...........................48
OPERATION.............................48
REMOVAL..............................48
INSTALLATION...........................49
THROTTLE CONTROL CABLE
REMOVAL..............................50
INSTALLATION...........................50
THROTTLE POSITION SENSOR
DESCRIPTION...........................51
OPERATION.............................51
REMOVAL..............................51
INSTALLATION...........................52
FUEL INJECTOR
DESCRIPTION...........................53
OPERATION.............................53
DIAGNOSIS AND TESTING.................53
FUEL INJECTOR TEST...................53
REMOVAL..............................53
INSTALLATION...........................53
FUEL INJECTION - GASOLINE
VISUAL INSPECTIONÐ3.9L/5.2L/5.9L
ENGINES
A visual inspection for loose, disconnected or incor-
rectly routed wires and hoses should be made. This
should be done before attempting to diagnose or ser-
vice the fuel injection system. A visual check will
help spot these faults and save unnecessary test and
diagnostic time. A thorough visual inspection will
include the following checks:
(1) Verify that the three 32±way electrical connec-
tors are fully inserted into the connector of the pow-
ertrain control module (PCM) (Fig. 1).(2) Inspect the battery cable connections. Be sure
that they are clean and tight.
(3) Inspect fuel pump relay and air conditioning
compressor clutch relay (if equipped). Inspect the
ASD relay connections. Inspect starter motor relay
connections. Inspect relays for signs of physical dam-
age and corrosion. The relays are located in the
Power Distribution Center (PDC) (Fig. 2). Refer to
label on PDC cover for relay location.
(4) Inspect ignition coil connections. Verify that
coil secondary cable is firmly connected to coil (Fig.
3).
14 - 28 FUEL INJECTION - GASOLINEBR/BE