1998 DODGE RAM 1500 fuel pump

(d) Insert special fuel line removal tool (Snap-On
number FIH 9055-1 or equivalent) into fuel line
(Fig. 14). Use tool to release locking fingers in end
of line.
(e) With special tool still inserted, pull fuel line
from fuel rail.
(f) After disconnection, locking fingers will
remain within quick-connect fitting at end of fuel
line.
(10) Disconnect quick-connect fitting from fuel sys-
tem component being serviced.
CONNECTING
(1) Inspect quick-connect fitting body and fuel sys-
tem component for damage. Replace as necessary.
(2) Prior to connecting quick-connect fitting to
component being serviced, check condition of fitting
and component. Clean parts with a lint-free cloth.
Lubricate with clean engine oil.
(3) Insert quick-connect fitting into fuel tube or
fuel system component until built-on stop on fuel
tube or component rests against back of fitting.
(4) Continue pushing until a click is felt.
(5) Single-tab type fitting: Push new tab down
until it locks into place in quick-connect fitting.
(6) Verify a locked condition by firmly pulling on
fuel tube and fitting (15-30 lbs.).
(7) Latch Clip Equipped: Install latch clip (snaps
into position).If latch clip will not fit, this indi-
cates fuel line is not properly installed to fuel
rail (or other fuel line). Recheck fuel line con-
nection.
(8) Connect negative cable to battery.
(9) Start engine and check for leaks.
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.
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 bottom section of
the fuel pump module 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 operational. 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 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.
The electric fuel pump is not a separate, service-
able component.
FUEL PUMP MODULE
DESCRIPTION
The fuel pump module assembly is located on the
top of the fuel tank (Fig. 1). The complete assembly
contains the following components:
²A combination fuel filter/fuel pressure regulator
²A separate fuel pick-up, or inlet filter
²An electric fuel pump
²A lockring to retain pump module to tank
²A soft gasket between tank flange and module
²A fuel gauge sending unit (fuel level sensor)
²Fuel line connection
The fuel gauge sending unit may be serviced sepa-
rately. If the electrical fuel pump, primary inlet filter,
fuel filter or fuel pressure regulator require service,
the fuel pump module must be replaced.
OPERATION
Refer to Fuel Pump, Inlet Filter, Fuel Filter / Fuel
Pressure Regulator and Fuel Gauge Sending Unit.
Fig. 14 FUEL LINE DISCONNECTION USING
SPECIAL TOOL
1 - SPECIAL FUEL LINE TOOL
2 - FUEL LINE
3 - FUEL RAIL
DRFUEL DELIVERY - GAS 14 - 11
QUICK CONNECT FITTING (Continued)

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
RELEASED.
(1) Drain and remove fuel tank. Refer to Fuel
Tank Removal/Installation.
(2) The plastic fuel pump module locknut (Fig. 15)
is threaded onto fuel tank. Install Special Tool 6856
to locknut and remove locknut (Fig. 16). The fuel
pump module will spring up slightly when locknut is
removed.
(3) Remove module from fuel tank.
INSTALLATION
CAUTION: Whenever the fuel pump module is ser-
viced, the rubber gasket must be replaced.
(1) Using a new gasket, position fuel pump module
into opening in fuel tank.
(2) Position locknut over top of fuel pump module.
Install locknut finger tight.
(3) Rotate module until embossed alignment arrow
(Fig. 15) points to center alignment mark. This step
must be performed to prevent float from contactingside of fuel tank. Also be sure fitting on fuel filter/
fuel pressure regulator is pointed to drivers side of
vehicle.
(4) Install Special Tool 6856 (Fig. 16) to locknut.
(5) Tighten locknut. Refer to Torque Specifications.
(6) Install fuel tank. Refer to Fuel Tank Removal/
Installation.
FUEL RAIL
DESCRIPTION
The fuel injector rail is used to mount the fuel
injectors to the engine.
OPERATION
High pressure from the fuel pump is routed to the
fuel rail. The fuel rail then supplies the necessary
fuel to each individual fuel injector.
A quick-connect fitting with a safety latch clip is
used to attach the fuel line to the fuel rail.
The fuel rail is not repairable.
CAUTION: The left and right sections of the fuel rail
are connected with either a flexible connecting
hose, or joints. Do not attempt to separate the rail
halves at these connecting hose or joints. Due to
the design of the connecting hose or joint, it does
not use any clamps. Never attempt to install a
clamping device of any kind to the hose or joint.
When removing the fuel rail assembly for any rea-
son, be careful not to bend or kink the connecting
hose or joint.
Fig. 15 FUEL PUMP MODULE (TOP)
1 - FUEL FILTER / FUEL PRESSURE REGULATOR
2 - ALIGNMENT ARROW
3 - TOP OF PUMP MODULE
4 - LOCKNUT
5 - ALIGNMENT MARKS
Fig. 16 LOCKNUT REMOVAL/INSTALLATION -
TYPICAL
1 - SPECIAL TOOL 6856
2 - LOCKNUT
14 - 12 FUEL DELIVERY - GASDR
FUEL PUMP MODULE (Continued)

(15) Install air duct to air box.
(16) Connect battery cable to battery.
(17) Start engine and check for leaks.
5.7L V-8
(1) If fuel injectors are to be installed, refer to Fuel
Injector Removal/Installation.
(2) Clean out fuel injector machined bores in
intake manifold.
(3) Apply a small amount of engine oil to each fuel
injector o-ring. This will help in fuel rail installation.
(4) Position fuel rail/fuel injector assembly to
machined injector openings in intake manifold.
(5) Guide each injector into intake manifold. Be
careful not to tear injector o-rings.
(6) Pushrightside of fuel rail down until fuel
injectors have bottomed on shoulders. Pushleftfuel
rail down until injectors have bottomed on shoulders.
(7) Install 4 fuel rail holdown clamps and 4 mount-
ing bolts. Refer to Torque Specifications.
(8) Position spark plug cable tray and cable assem-
bly to intake manifold. Snap 4 cable tray retaining
clips into intake manifold.
(9) Install all cables to spark plugs and ignition
coils.
(10) Connect electrical connector to throttle body.
(11) Install electrical connectors to all 8 ignition
coils. Refer to Ignition Coil Removal/Installation.
(12) Connect electrical connector to throttle body.
(13) Connect electrical connectors at all fuel injec-
tors. To install connector, refer to (Fig. 17). 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.
(14) Connect fuel line latch clip and fuel line to
fuel rail. Refer to Quick-Connect Fittings.
(15) Install air resonator to throttle body (2 bolts).
(16) Install flexible air duct to air box.
(17) Connect battery cable to battery.
(18) Start engine and check for leaks.
FUEL TANK
DESCRIPTION
The fuel tank is constructed of a plastic material.
Its main functions are for fuel storage and for place-
ment of the fuel pump module, and (if equipped) cer-
tain ORVR components.
OPERATION
All models pass a full 360 degree rollover test
without fuel leakage. To accomplish this, fuel and
vapor flow controls are required for all fuel tank con-
nections.Two check (control) valves are mounted into the
top of the fuel tank. Refer to Fuel Tank Check Valve
for additional information.
An evaporation control system is connected to the
fuel tank to reduce emissions of fuel vapors into the
atmosphere. When fuel evaporates from the fuel
tank, vapors pass through vent hoses or tubes to a
charcoal canister where they are temporarily held.
When the engine is running, the vapors are drawn
into the intake manifold. Certain models are also
equipped with a self-diagnosing system using a Leak
Detection Pump (LDP) and/or an On-Board Refueling
Vapor Recovery (ORVR) system. Refer to Emission
Control System for additional information.
REMOVAL- EXCEPT DIESEL
Fuel Tank Draining
WARNING: THE FUEL SYSTEM MAY BE UNDER
CONSTANT FUEL PRESSURE EVEN WITH THE
ENGINE OFF. THIS PRESSURE MUST BE
RELEASED BEFORE SERVICING FUEL TANK.
Two different procedures may be used to drain fuel
tank: through the fuel fill fitting on tank, or using
the DRBtscan tool. Due to a one-way check valve
installed into the fuel fill opening fitting at the tank,
the tank cannot be drained conventionally at the fill
cap.
The quickest draining procedure involves removing
the rubber fuel fill hose.
As an alternative procedure, the electric fuel pump
may be activated allowing tank to be drained at fuel
rail connection. Refer to DRB scan tool for fuel pump
activation procedures. Before disconnecting fuel line
at fuel rail, release fuel pressure. Refer to the Fuel
System Pressure Release Procedure for procedures.
Attach end of special test hose tool number 6541,
6539, 6631 or 6923 at fuel rail disconnection (tool
number will depend on model and/or engine applica-
tion). Position opposite end of this hose tool to an
approved gasoline draining station. Activate fuel
pump and drain tank until empty.
If electric fuel pump is not operating, fuel must be
drained through fuel fill fitting at tank. Refer to fol-
lowing procedures.
(1) Release fuel system pressure.
(2) Raise vehicle.
(3) Thoroughly clean area around fuel fill fitting
and rubber fuel fill hose at tank.
(4) If vehicle is equipped with 4 doors and a 6 foot
(short) box, remove left-rear tire/wheel.
(5) Loosen clamp (Fig. 23) and disconnect rubber
fuel fill hose at tank fitting. Using an approved gas
holding tank, drain fuel tank through this fitting.
DRFUEL DELIVERY - GAS 14 - 17
FUEL RAIL (Continued)

Tank Removal
(1) Loosen clamp and disconnect rubber fuel vent
hose (Fig. 23) at tank fitting.
(2) Support tank with a hydraulic jack.
(3) Remove 2 fuel tank strap nuts (Fig. 24) and
remove both tank support straps.
(4) Carefully lower tank a few inches and discon-
nect fuel pump module electrical connector (Fig. 25)
at top of tank. To disconnect electrical connector:
Push upward on red colored tab to unlock. Push on
black colored tab while removing connector.(5) Disconnect fuel line at fuel filter / fuel pressure
regulator (Fig. 25) by pressing on tabs at side of
quick-connect fitting.
(6) Disconnect EVAP line at top of tank (Fig. 1).
(7) Continue to lower tank for removal.
(8) If fuel tank is to be replaced, remove fuel pump
module from tank. Refer to Fuel Pump Module
Removal/Installation procedures.
Fig. 23 FUEL TANK FILL / VENT HOSES
1 - BEZEL SCREWS
2 - FUEL FILL BEZEL
3 - HOSE CLAMPS4 - VENT HOSE
5 - FUEL TANK
6 - FILL HOSE
14 - 18 FUEL DELIVERY - GASDR
FUEL TANK (Continued)

INSTALLATION - EXCEPT DIESEL
(1) If fuel tank is to be replaced, install fuel pump
module into tank. Refer to Fuel Pump Module
Removal/Installation procedures.
(2) Disconnect clamps and remove rubber fuel fill
hose and fuel vent hose at fuel fill tube. Install these
2 hoses to 2 fuel tank fittings. Rotate hoses until
paint marks on hoses line up with alignment marks
(Fig. 26). Tighten both clamps.
(3) Position fuel tank to hydraulic jack.
(4) Raise tank until positioned near body.
(5) Connect EVAP line at tank (Fig. 1).
(6) Connect fuel pump module electrical connector
(Fig. 25) at top of tank.
(7) Connect fuel line quick-connect fitting to fuel
filter / fuel pressure regulator (Fig. 1) or (Fig. 25).
(8) Continue raising tank until positioned snug to
body.(9) Install and position both tank support straps.
Install 2 fuel tank strap nuts (Fig. 24) and tighten.
Tighten rear strap nut first.Refer to Torque Spec-
ifications.
(10) Connect rubber fill and vent hoses to fuel fill
tube and tighten clamps.
(11) Lower vehicle.
(12) Fill fuel tank with fuel.
(13) Start engine and check for fuel leaks near top
of module.
Fig. 24 FUEL TANK MOUNTING
1 - FUEL TANK
2 - STRAP MOUNTING STUDS
3 - VEHICLE FRAME4 - MOUNTING STRAPS
5 - STRAP NUTS
DRFUEL DELIVERY - GAS 14 - 19
FUEL TANK (Continued)

INLET FILTER
REMOVAL
The fuel pump inlet filter (strainer) is located on
the bottom of the fuel pump module (Fig. 27). The
fuel pump module is located inside of fuel tank.
(1) Remove fuel tank. Refer to Fuel Tank Removal/
Installation.
(2) Remove fuel pump module. Refer to Fuel Pump
Module Removal/Installation.
(3) Remove filter by carefully prying 2 lock tabs at
bottom of module with 2 screwdrivers. Filter is
snapped to module.
(4) Clean bottom of pump module.
INSTALLATION
The fuel pump inlet filter (strainer) is located on
the bottom of the fuel pump module (Fig. 27). The
fuel pump module is located inside of fuel tank.
(1) Snap new filter to bottom of module. Be sure
o-ring is in correct position.
(2) Install fuel pump module. Refer to Fuel Pump
Module Removal/Installation.
(3) Install fuel tank. Refer to Fuel Tank Removal/
Installation.
Fig. 25 FUEL PUMP MODULE CONNECTIONS
1 - TOP OF FUEL TANK
2 - FUEL PUMP MODULE
3 - FUEL FILTER / FUEL PRESSURE REGULATOR
4 - ELEC. CONNECT.
Fig. 26 HOSE ALIGNMENT MARKS
1 - ALIGNMENT MARKS (MARK FOR FILL HOSE IS LOCATED
ON FUEL TANK - MARK FOR VENT HOSE IS LOCATED ON
FITTING)
2 - PAINT MARKS ON RUBBER HOSES
Fig. 27 FUEL PUMP INLET FILTER
1 - FUEL PUMP INLET FILTER
2 - LOCK TABS (2)
3 - FUEL PUMP MODULE (BOTTOM)
14 - 20 FUEL DELIVERY - GASDR
FUEL TANK (Continued)

FUEL INJECTION - GAS
TABLE OF CONTENTS
page page
ACCELERATOR PEDAL
REMOVAL.............................21
INSTALLATION.........................21
ACCELERATOR PEDAL POSITION SENSOR
DESCRIPTION.........................22
OPERATION...........................22
REMOVAL.............................22
INSTALLATION.........................22
CRANKSHAFT POSITION SENSOR
DESCRIPTION.........................23
OPERATION...........................23
REMOVAL.............................24
INSTALLATION.........................25
FUEL INJECTOR
DESCRIPTION.........................26
OPERATION
OPERATION - FUEL INJECTOR..........26
OPERATION - PCM OUTPUT............27
REMOVAL.............................27
INSTALLATION.........................27
FUEL PUMP RELAY
DESCRIPTION.........................27
OPERATION...........................27
REMOVAL.............................28
INSTALLATION.........................28
IDLE AIR CONTROL MOTOR
DESCRIPTION.........................28
OPERATION...........................28
REMOVAL.............................29
INSTALLATION.........................29INTAKE AIR TEMPERATURE SENSOR
DESCRIPTION.........................30
OPERATION...........................30
REMOVAL.............................30
INSTALLATION.........................31
MAP SENSOR
DESCRIPTION.........................32
OPERATION...........................32
REMOVAL.............................33
INSTALLATION.........................34
OXYGEN SENSOR
DESCRIPTION.........................35
REMOVAL.............................35
INSTALLATION.........................36
PTO SWITCH
DESCRIPTION.........................36
OPERATION...........................36
THROTTLE BODY
DESCRIPTION.........................36
OPERATION...........................36
REMOVAL.............................36
INSTALLATION.........................37
THROTTLE CONTROL CABLE
REMOVAL.............................38
INSTALLATION.........................40
THROTTLE POSITION SENSOR
DESCRIPTION.........................41
OPERATION...........................41
REMOVAL.............................41
INSTALLATION.........................43
ACCELERATOR PEDAL
REMOVAL
The following procedure applies only to vehicles
without the Adjustable Pedal Package (code XAP).
The accelerator pedal is serviced as a complete
assembly including the bracket.
The accelerator cable is connected to the upper
part of the accelerator pedal arm by a plastic
retainer (clip) (Fig. 1). This plastic retainer snaps
into the top of the accelerator pedal arm.
(1) From inside the vehicle, hold up accelerator
pedal. Remove plastic cable retainer (clip) and throt-
tle cable core wire from upper end of accelerator
pedal arm (Fig. 1). Plastic cable retainer (clip) snaps
into pedal arm.(2) Remove 2 accelerator pedal mounting bracket
nuts. Remove accelerator pedal assembly.INSTALLATION
(1) Place accelerator pedal assembly over 2 studs.
(2) Install and tighten 2 mounting nuts. Refer to
Torque Specifications.
(3) Slide throttle cable into opening slot in top of
pedal arm.
(4) Push plastic cable retainer (clip) into accelera-
tor pedal arm opening until it snaps into place.
(5) Before starting engine, operate accelerator
pedal to check for any binding.
DRFUEL INJECTION - GAS 14 - 21

stream. The spraying action atomizes the fuel, add-
ing it to the air entering the combustion chamber.
The nozzle (outlet) ends of the injectors are posi-
tioned into openings in the intake manifold just
above the intake valve ports of the cylinder head.
The engine wiring harness connector for each fuel
injector is equipped with an attached numerical tag
(INJ 1, INJ 2 etc.). This is used to identify each fuel
injector.
The injectors are energized individually in a
sequential order by the Powertrain Control Module
(PCM). The PCM will adjust injector pulse width by
switching the ground path to each individual injector
on and off. Injector pulse width is the period of time
that the injector is energized. The PCM will adjust
injector pulse width based on various inputs it
receives.
Battery voltage is supplied to the injectors through
the ASD relay.
The PCM determines injector pulse width based on
various inputs.
OPERATION - PCM OUTPUT
The nozzle ends of the injectors are positioned into
openings in the intake manifold just above the intake
valve ports of the cylinder head. The engine wiring
harness connector for each fuel injector is equipped
with an attached numerical tag (INJ 1, INJ 2 etc.).
This is used to identify each fuel injector with its
respective cylinder number.
The injectors are energized individually in a
sequential order by the Powertrain Control Module
(PCM). The PCM will adjust injector pulse width by
switching the ground path to each individual injector
on and off. Injector pulse width is the period of time
that the injector is energized. The PCM will adjust
injector pulse width based on various inputs it
receives.
Battery voltage (12 volts +) is supplied to the injec-
tors through the ASD relay. The ASD relay will shut-
down the 12 volt power source to the fuel injectors if
the PCM senses the ignition is on, but the engine is
not running. This occurs after the engine has not
been running for approximately 1.8 seconds.
The PCM determines injector on-time (pulse width)
based on various inputs.
REMOVAL
(1) Remove fuel rail. Refer to Fuel Injector Rail
Removal.
(2) Disconnect clip(s) that retain fuel injector(s) to
fuel rail (Fig. 12).
INSTALLATION
(1) Install fuel injector(s) into fuel rail assembly
and install retaining clip(s).(2) If same injector(s) is being reinstalled, install
new o-ring(s).
(3) Apply a small amount of clean engine oil to
each injector o-ring. This will aid in installation.
(4) Install fuel rail. Refer to Fuel Rail Installation.
(5) Start engine and check for fuel leaks.
FUEL PUMP RELAY
DESCRIPTION
The 5±pin, 12±volt, fuel pump relay is located in
the Power Distribution Center (PDC). Refer to the
label on the PDC cover for relay location.
OPERATION
The Powertrain Control Module (PCM) energizes
the electric fuel pump through the fuel pump relay.
The fuel pump relay is energized by first applying
battery voltage to it when the ignition key is turned
ON, and then applying a ground signal to the relay
from the PCM.
Whenever the ignition key is turned ON, the elec-
tric fuel pump will operate. But, the PCM will shut-
down the ground circuit to the fuel pump relay in
approximately 1±3 seconds unless the engine is oper-
ating or the starter motor is engaged.
Fig. 12 INJECTOR RETAINING CLIP
1 - PLIERS
2 - INJECTOR CLIP
3 - FUEL INJECTOR - TYPICAL
4 - FUEL RAIL - TYPICAL
DRFUEL INJECTION - GAS 14 - 27
FUEL INJECTOR (Continued)