1998 DODGE RAM 1500 fuel tank

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Data Link Connector - Engine
(Diesel)BK Near T/O for Water In Fuel Sensor N/S
Dome Lamp BK Center of Headliner N/S
Door Ajar Switch-Driver (Base) BK Left Front Door 41
Door Ajar Switch-Left Rear (Base) BK Left Rear Door 43
Door Ajar Switch-Right Rear (Base) BK Right Rear Door 43
Door Lock Motor/Ajar Switch-Driver
(Except Base)BK Left Front Door 41
Door Lock Motor/Ajar Switch-Left
Rear (Except Base)BK Left Rear Door 43
Door Lock Motor/Ajar Switch-
PassengerBK Right Front Door 42
Door Lock Motor/Ajar Switch-Right
Rear (Except Base)BK Right Rear Door 43
Door Lock Switch-Passenger BL In Right Front Door 42
Driver Airbag Squib BK In Steering Column N/S
Driver Blend Door Actuator (Dual
Zone)BK Right Side of HVAC N/S
Driver Door Module C1 BL In Left Front Door 41
Driver Door Module C2 BL In Left Front Door 41
EGR Solenoid Right Front Engine 9
Electric Brake Provision Rear of Engine 22, 24
Engine Control Module C1 BK Left Engine 10
Engine Control Module C2 BK Left Engine 10
Engine Coolant Temperature
SensorBK Near Generator 6
Engine Oil Pressure Switch BK Lower Left Side of Engine 6, 9
Evap/Purge Solenoid BK Left Fender Side Shield 23, 25
Evaporator Temperature Sensor BK Right Side of HVAC N/S
Fog Lamp-Left WT Left Front Facia N/S
Fog Lamp-Right WT Right Front Facia N/S
Fuel Control Actuator (Diesel) BK Left Rear Engine N/S
Fuel Heater (Diesel) BK Left Side Engine 10
Fuel Injector No. 1 BK At Fuel Injector 6
Fuel Injector No. 2 BK At Fuel Injector 3
Fuel Injector No. 3 BK At Fuel Injector 6
Fuel Injector No. 4 BK At Fuel Injector 3
Fuel Injector No. 5 BK At Fuel Injector 6
Fuel Injector No. 6 BK At Fuel Injector 3
Fuel Injector No. 7 BK At Fuel Injector 6
Fuel Injector No. 8 BK At Fuel Injector 3
Fuel Pump Module LT GY At Fuel Tank 50
Fuel Pump Motor (Diesel) BK Left Side Engine 10
Generator BK Front of Engine 6, 9, 10
8W - 91 - 4 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONDR
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
2. Engine running too cold. 2. Refer to Coolant Temperature Below
Normal (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
3. Oil viscosity too thick. 3. Make sure the correct oil is being used.
(Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
4. Oil pressure relief valve stuck
closed or binding4. Check and replace valve.
LUBRICATING OIL LOSS 1. External leaks. 1. Visually inspect for oil leaks. Repair as
required.
2. Crankcase being overfilled. 2. Verify that the correct dipstick is being
used.
3. Incorrect oil specification or
viscosity.3. (a) Make sure the correct oil is being
used (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
(b) Look for reduced viscosity from dilution
with fuel.
(c) Review/reduce oil change intervals.
4. Oil cooler leak 4. Check and replace the oil cooler.
5. High blow-by forcing oil out the
breather.5. Check the breather tube area for signs of
oil loss. Perform the required repairs.
6. Turbocharger leaking oil to the air
intake.6. Inspect the air ducts for evidence of oil
transfer. Repair as required.
COMPRESSION KNOCKS 1. Air in the fuel system. 1. Identify location of air leak and repair. Do
not bleed high pressure fuel system.
2. Poor quality fuel or water/gasoline
contaminated fuel.2. Verify by operating from a temporary
tank with good fuel. Clean and flush the
fuel tank. Replace fuel/water separator filter.
3. Engine overloaded. 3. Verify the engine load rating is not being
exceeded.
4. Improperly operating injectors. 5. Check and replace misfiring/inoperative
injectors.
EXCESSIVE VIBRATION 1. Loose or broken engine mounts. 1. Replace engine mounts.
2. Damaged fan or improperly
operating accessories.2. Check and replace the vibrating
components.
3. Improperly operating vibration
damper3. Inspect/replace vibration damper.
4. Improperly operating electronically
controlled viscous fan drive.4. Inspect/replace fan drive.
5. Worn or damaged generator
bearing.5. Check/replace generator.
6. Flywheel housing misaligned. 6. Check/correct flywheel alignment.
9 - 234 ENGINE 5.9L DIESELDR
ENGINE 5.9L DIESEL (Continued)

EXCESSIVE WHITE SMOKE
POSSIBLE CAUSE CORRECTION
Air in fuel supply: Possible leak in fuel supply side (between
transfer pump and fuel tank module).(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY/FUEL
TRANSFER PUMP - DIAGNOSIS AND TESTING).
Coolant leaking into combustion chamber. Do pressure test of cooling system (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
Diagnostic Trouble Codes (DTC's) active or multiple,
intermittent DTC's.Refer to Powertrain Diagnostic Procedures Information.
In very cold ambient temperatures, engine block heater is
malfunctioning (if equipped).(Refer to 7 - COOLING/ENGINE/ENGINE BLOCK HEATER -
REMOVAL).
Engine coolant temperature sensor malfunctioning. A DTC should have been set. Refer to Powertrain Diagnostic
Procedures Information. Also check thermostat operation
(Refer to 7 - COOLING/ENGINE/ENGINE COOLANT
THERMOSTAT - DIAGNOSIS AND TESTING).
Engine Control Module (ECM) not calibrated or has incorrect
calibration.A DTC should have been set. Refer to Powertrain Diagnostic
Procedures Information.
Fuel filter plugged. Refer to Powertrain Diagnostic Manual for fuel system testing.
Fuel grade not correct or fuel quality is poor. Temporarily change fuel brands and note condition. Change
brand if necessary.
Fuel heater element or fuel heater temperature sensor
malfunctioning. This will cause wax type build-up in fuel filter.Refer to Fuel Heater Testing (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY/FUEL HEATER - DIAGNOSIS AND
TESTING).
Fuel injector malfunctioning. A DTC should have been set. Perform9Cylinder cutout Test9
using DRB scan tool to isolate individual cylinders. Also refer
to Powertrain Diagnostic Procedures Information and, (Refer
to 14 - FUEL SYSTEM/FUEL INJECTION/FUEL INJECTOR -
DIAGNOSIS AND TESTING).
Fuel injector hold-downs loose. Torque to specifications.
Fuel injector protrusion not correct. Check washer (shim) at bottom of fuel injector for correct
thickness. (Refer to 14 - FUEL SYSTEM/FUEL INJECTION/
FUEL INJECTOR - INSTALLATION)
Fuel injection pump malfunctioning. A DTC should have been set. Refer to Powertrain Diagnostic
Procedures Information.
Fuel supply side restriction to transfer pump. Refer to Powertrain Diagnostic Manual for fuel system testing.
Fuel transfer (lift) pump malfunctioning. A DTC may have been set. Refer to Powertrain Diagnostic
Procedures Information.
Intake/Exhaust valve adjustments not correct (too tight). (Refer to 9 - ENGINE/CYLINDER HEAD/INTAKE/EXHAUST
VALVES & SEATS - STANDARD PROCEDURE).
Intake manifold air temperature sensor malfunctioning. A DTC should have been set. Refer to Powertrain Diagnostic
Procedures Information.
Intake manifold heater circuit not functioning correctly in cold
weather.A DTC should have been set. Refer to Powertrain Diagnostic
Procedures Information. Also check heater elements for
correct operation.
Intake manifold heater elements not functioning correctly in
cold weather.A DTC should have been set if heater elements are
malfunctioning. Refer to Powertrain Diagnostic Procedures
Information.
Internal engine damage (scuffed cylinder). Analyze engine oil and inspect oil filter to locate area of
probable damage.
Restriction in fuel supply side of fuel system. Refer to Powertrain Diagnostic Manual for fuel system testing.
DRENGINE 5.9L DIESEL 9 - 237
ENGINE 5.9L DIESEL (Continued)

DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION/LEAKAGE TESTS
CYLINDER COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure batteries are completely charged and the
engine starter motor is in good operating condition.
Otherwise, the indicated compression pressures may
not be valid for diagnostic purposes.
(1) Disconnect the fuel inlet line to the fuel trans-
fer pump. Plug the fuel line from the fuel tank.
(2) Start the engine and idle until the engine stalls
(runs out of fuel).
(3) Disconnect all three injector wire harness con-
nectors at the rocker housing.
(4) Remove the breather cover and cylinder head
cover.
(5) Remove the high pressure fuel line between the
cylinder head and fuel rail for the cylinder to be
tested. Use tool# 9011 to cap this fuel rail on the cyl-
inder being tested.
(6) Remove the exhaust rocker lever.
(7) Use Tool 9010 to remove the injector and cop-
per sealing washer.
(8) Install the exhaust rocker lever and torque to
36 N´m (27 ft. lbs.).
(9) Cover the remaining rocker levers with clean
shop towels to prevent any oil splatter under the
hood.
(10) Place a rag over the compression test tool fit-
ting. Crank the engine for 2±3 seconds to purge any
fuel that may have drained into the cylinder when
the injector was removed.
(11) Connect the compression test gauge.
(12) Crank the engine for 5 seconds and record the
pressure reading. Repeat this step three times and
calculate the average of the three readings.
NOTE: The minimum cylinder pressure is 350 psi.
Cylinder pressure should be within 20% from cylin-
der to cylinder.
(13) Combustion pressure leakage can be checked
if cylinder pressure is below the specification. Per-
form the leakage test procedure on each cylinder
according to the tester manufacturer instructions.
(14) Upon completion of the test check an erase
any engine related fault codes.
CYLINDER COMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:²Exhaust and intake valve leaks (improper seat-
ing).
²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss
(1) Start and operate the engine until it attains
normal operating temperature.
(2) Remove the breather cover and cylinder head
cover.
(3) Disconnect all three injector wire harness con-
nectors at the rocker housing.
(4) Bring the cylinder to be tested to TDC.
(5) Remove the high pressure fuel line between the
cylinder head and the fuel rail for the cylinder to be
tested.
(6) Install capping Tool 9011 onto the rail.
(7) Remove the high pressure connector nut and
high pressure connector with Tool 9015.
(8) Remove the exhaust and intake rocker lever.
(9) Use Tool 9010 to remove the injector and cop-
per sealing washer.
(10) Install compression test Tool 9007 into the
injector bore.
(11) Connect the leakage tester and perform the
leakage test procedure on each cylinder according to
the tester manufacturer's instructions.
(12) Upon completion of the test check and erase
any engine related fault codes.
STANDARD PROCEDURE
STANDARD PROCEDURE - FORM-IN-PLACE
GASKETS AND SEALERS
There are numerous places where form-in-place
gaskets are used on the engine. Care must be taken
when applying form-in-place gaskets to assure
obtaining the desired results.Do not use form-in-
place gasket material unless specified.Bead size,
continuity, and location are of great importance. Too
thin a bead can result in leakage while too much can
result in spill-over which can break off and obstruct
fluid feed lines. A continuous bead of the proper
width is essential to obtain a leak-free gasket.
There are numerous types of form-in-place gasket
materials that are used in the engine area. Mopart
Engine RTV GEN II, MopartATF-RTV, and Mopart
Gasket Maker gasket materials, each have different
properties and can not be used in place of the other.
MOPARtENGINE RTV GEN II
MopartEngine RTV GEN II is used to seal com-
ponents exposed to engine oil. This material is a spe-
cially designed black silicone rubber RTV that
retains adhesion and sealing properties when
exposed to engine oil. Moisture in the air causes the
DRENGINE 5.9L DIESEL 9 - 239
ENGINE 5.9L DIESEL (Continued)

FUEL SYSTEM
TABLE OF CONTENTS
page page
FUEL DELIVERY - GAS....................1
FUEL INJECTION - GAS...................21FUEL DELIVERY - DIESEL.................44
FUEL INJECTION - DIESEL................68
FUEL DELIVERY - GAS
TABLE OF CONTENTS
page page
FUEL DELIVERY - GAS
DESCRIPTION..........................1
OPERATION............................2
STANDARD PROCEDURE - FUEL SYSTEM
PRESSURE RELEASE...................2
SPECIFICATIONS
FUEL SYSTEM PRESSURE..............3
TORQUE - FUEL SYSTEM - EXCEPT
DIESEL..............................3
SPECIAL TOOLS
FUEL SYSTEM........................5
FUEL FILTER/PRESSURE REGULATOR
DESCRIPTION..........................5
OPERATION............................6
FUEL LEVEL SENDING UNIT / SENSOR
DESCRIPTION..........................6
OPERATION............................6
REMOVAL.............................7
INSTALLATION..........................7
FUEL LINES
DESCRIPTION..........................7
QUICK CONNECT FITTING
DESCRIPTION..........................8STANDARD PROCEDURE - QUICK-CONNECT
FITTINGS............................8
FUEL PUMP
DESCRIPTION.........................11
OPERATION...........................11
FUEL PUMP MODULE
DESCRIPTION.........................11
OPERATION...........................11
REMOVAL.............................12
INSTALLATION.........................12
FUEL RAIL
DESCRIPTION.........................12
OPERATION...........................12
REMOVAL.............................13
INSTALLATION.........................15
FUEL TANK
DESCRIPTION.........................17
OPERATION...........................17
REMOVAL- EXCEPT DIESEL..............17
INSTALLATION - EXCEPT DIESEL..........19
INLET FILTER
REMOVAL.............................20
INSTALLATION.........................20
FUEL DELIVERY - GAS
DESCRIPTION
The fuel delivery system consists of:
²a fuel pump module containing the electric fuel
pump, fuel filter/fuel pressure regulator, fuel gauge
sending unit (fuel level sensor) and a secondary fuel
filter located at the bottom of the pump module
²fuel tubes/lines/hoses
²a combination fuel filter/fuel pressure regulator
²quick-connect fittings²fuel injector rail
²fuel tank
²fuel tank filler/vent tube assembly
²fuel tank filler tube cap
²accelerator pedal
²throttle cable
Certain fuel delivery components can be found in
(Fig. 1).
DRFUEL SYSTEM 14 - 1

OPERATION
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.
The fuel tank assembly consists of: the fuel tank,
fuel pump module assembly, fuel pump module lock-
nut/gasket, and fuel tank check valve (refer to Fuel
Tank Check Valve for 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.
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.
Fig. 1 FUEL DELIVERY COMPONENTS
1 - FUEL TANK 8 - LDP FRESH AIR FILTER
2 - CHECK VALVE 9 - LEAK DETECTION PUMP
3 - LIQUID EXPANSION CHAMBER 10 - EVAP CANISTERS (2)
4 - FUEL FILTER / FUEL PRESSURE REGULATOR 11 - FUEL TANK STRAPS (2)
5 - QUICK-CONNECT FITTING AND FUEL LINE (TO ENGINE) 12 - CHECK VALVE
6 - EVAP LINE CONNECTION 13 - FUEL PUMP MODULE LOCK RING
7 - LEAK DETECTION PUMP FRESH AIR LINE 14 - FUEL PUMP MODULE
14 - 2 FUEL DELIVERY - GASDR
FUEL DELIVERY - GAS (Continued)

DESCRIPTION N-m Ft. Lbs. In. Lbs.
Engine Coolant
Temperature Sensor -
5.7L11 - 9 6
EVAP Canister- to-Bracket
Nuts8.5 - 75
EVAP Canister-to-frame
bolts34 25
Fuel Filler Hose Clamp at
Tank3-30
Fuel Filler Housing-to-
Body Screws2-17
Fuel Pump Module Lock
Ring54 40 -
Fuel Rail Mounting Bolts -
3.7L11 -
100
Fuel Rail Mounting Bolts -
4.7L11 - 100
Fuel Rail Mounting Bolts -
5.7L11 - 100
Fuel Tank Mounting Straps 41 30 -
IAC Motor Mounting
Screws - 3.7L7-60
IAC Motor Mounting
Screws - 4.7L7-60
Leak Detection Pump
Mounting Bolt8.5 - 75
Map Sensor Mounting
Screws - 3.7L3-25
Map Sensor Mounting
Screws - 4.7L3-25
PCM-to-Mounting Bracket
Mounting Screws4-35
Power Steering Pressure
Switch - 3.7L14-22 - 124-195
Power Steering Pressure
Switch - 4.7L14-22 - 124-195
TPS Mounting Screws -
3.7L7-60
TPS Mounting Screws -
4.7L7-60
Throttle Body Mounting
Bolts - 3.7L11 - 100
Throttle Body Mounting
Bolts - 4.7L12 - 105
Throttle Body Mounting
Bolts - 5.7L12 - 105
Oxygen Sensors 30 22 -
14 - 4 FUEL DELIVERY - GASDR
FUEL DELIVERY - GAS (Continued)

OPERATION
Fuel Pressure Regulator Operation:The pres-
sure regulator is a mechanical device that is not con-
trolled by engine vacuum or the Powertrain Control
Module (PCM).
The regulator is calibrated to maintain fuel system
operating pressure of approximately 58   2 psi at the
fuel injectors. It contains a diaphragm, calibrated
springs and a fuel return valve. The internal fuel fil-
ter (Fig. 2) is also part of the assembly.
Fuel is supplied to the filter/regulator by the elec-
tric fuel pump through an opening tube at the bot-
tom of filter/regulator (Fig. 2).
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.Refer to Fuel Pump - Description and
Operation for more information.
If fuel pressure at the pressure regulator exceeds
approximately 60 psi, an internal diaphragm opens
and excess fuel pressure is routed back into the tank
through the bottom of pressure regulator.
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.
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 is supplied to the resistor track on the fuel
gauge sending unit. This is fed directly from the
Powertrain Control Module (PCM).NOTE: For
diagnostic purposes, this 12V power source can
only be verified with the circuit opened (fuel
pump module electrical connector unplugged).
With the connectors plugged, output voltages
will vary from about 0.6 volts at FULL, to about
8.6 volts at EMPTY (about 8.6 volts at EMPTY
for Jeep models, and about 7.0 volts at EMPTY
for Dodge Truck models).The resistor track is
used to vary the voltage (resistance) depending 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 sensor return
circuit.
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.
Fig. 2 SIDE VIEW - FILTER/REGULATOR
1 - INTERNAL FUEL FILTER
2 - FUEL FLOW TO FUEL INJECTORS
3 - FUEL FILTER/FUEL PRESSURE REGULATOR
4 - EXCESS FUEL BACK TO TANK
5 - FUEL INLET
6 - RUBBER GROMMET
7 - TOP OF PUMP MODULE
14 - 6 FUEL DELIVERY - GASDR
FUEL FILTER/PRESSURE REGULATOR (Continued)