1998 DODGE RAM 1500 Timing

FUEL DELIVERY - DIESEL
DESCRIPTION - DIESEL FUEL SYSTEM
The fuel system used on the Cummins engine is an
electronically controlled, Bosch HPCR (High-Pressure
Common Rail) system. The HPCR system consists of
five main components:
²Electric Fuel Transfer (lift) Pump
²Fuel Pump/Gear Pump (attached to fuel injec-
tion pump)
²High-Pressure Fuel Injection Pump
²Fuel Injection Rail
²Fuel Injectors
Also to be considered as part of the overall fuel
system are:
²Accelerator Pedal
²Air Cleaner Housing/Element
²Fuel Drain Manifold (passage)
²Fuel Drain Valve (at filter)
²Fuel Filter/Water Separator
²Fuel Heater
²Fuel Heater Relay
²Fuel Level (gauge) Sending Unit
²Fuel Pressure Limiting Valve
²Fuel Tank
²Fuel Tank Module (containing fuel gauge send-
ing unit and separate fuel filter located at bottom of
tank module)
²Fuel Tank Filler/Vent Tube Assembly
²Fuel Tank Filler Tube Cap
²Fuel Tubes/Lines/Hoses
²High-Pressure Fuel Injector Lines
²In-Tank Fuel Filter (at bottom of fuel tank mod-
ule)
²Low-Pressure Fuel Supply Lines
²Low-Pressure Fuel Return Line
²Overflow Valve
²Quick-Connect Fuel Line Fittings
²Throttle Cable
²Water Draining (maintenance)
²Water-In-Fuel (WIF) Sensor
The fuel injection pump supplies high pressure to
the fuel rail independent of engine speed. This high
pressure fuel is then accumulated in the fuel rail.
High pressure fuel is constantly supplied to the injec-
tors by the fuel rail. The Engine Control Module
(ECM) controls the fueling and timing of the engine
by actuating the injectors.Fuel enters the system from the electric fuel trans-
fer (lift) pump, which is attached to the fuel filter
assembly. Fuel is forced through the fuel filter ele-
ment and then enters the Fuel Pump/Gear Pump,
which is attached to the rear of the fuel injection
pump. The Fuel Pump/Gear Pump is a low-pressure
pump and produce pressures ranging from 551.5 kpa
(80 psi) to 1241 kpa (180) psi. Fuel then enters the
fuel injection pump. Low pressure fuel is then sup-
plied to the FCA (Fuel Control Actuator).
The FCA is an electronically controlled solenoid
valve. The ECM controls the amount of fuel that
enters the high-pressure pumping chambers by open-
ing and closing the FCA based on a demanded fuel
pressure. The FPS (Fuel Pressure Sensor) on the fuel
rail monitors the actual fuel pressure and provides it
as an input to the ECM. When the actuator is
opened, the maximum amount of fuel is being sup-
plied to the fuel injection pump. Any fuel that does
not enter the injection pump is directed to the over-
flow valve. The overflow valve regulates how much
excess fuel is used for lubrication of the pump and
how much is returned to the tank through the drain
manifold.
Fuel entering the injection pump is pressurized to
between 300-1600 bar (4351-23,206 psi) by three
radial pumping chambers. The pressurized fuel is
then supplied to the fuel rail.
WARNING: HIGH-PRESSURE FUEL LINES DELIVER
DIESEL FUEL UNDER EXTREME PRESSURE FROM
THE INJECTION PUMP TO THE FUEL INJECTORS.
THIS MAY BE AS HIGH AS 160,000 KPA (23,206
PSI). USE EXTREME CAUTION WHEN INSPECTING
FOR HIGH-PRESSURE FUEL LEAKS. INSPECT FOR
HIGH-PRESSURE FUEL LEAKS WITH A SHEET OF
CARDBOARD. HIGH FUEL INJECTION PRESSURE
CAN CAUSE PERSONAL INJURY IF CONTACT IS
MADE WITH THE SKIN.
Certain fuel system components can be found in
(Fig. 1), or (Fig. 2).
DRFUEL DELIVERY - DIESEL 14 - 45

(3) Check condition of relay terminals and PDC
connector terminals for damage or corrosion. Repair
if necessary before installing relay.
(4) Check for pin height (pin height should be the
same for all terminals within the PDC connector).
Repair if necessary before installing relay.
INSTALLATION
The fuel heater relay is located in the Power Dis-
tribution Center (PDC) (Fig. 6). Refer to label under
PDC cover for relay location.
(1) Install relay to PDC.
(2) Install cover to PDC.
FUEL INJECTION PUMP
DESCRIPTION
A Robert Bosch high-pressure fuel injection pump
is used. The pump is attached to the back of the tim-
ing gear cover at the left / rear side of the engine.
OPERATION
The fuel injection pump supplies high pressure to
the fuel rail independent of engine speed. This high
pressure is then accumulated in the fuel rail. High
pressure fuel is constantly supplied to the injectors
by the fuel rail. The Engine Control Module (ECM)
controls the fueling and timing of the engine by actu-
ating the injectors.
Fuel enters the system from the electric fuel trans-
fer (lift) pump, which is attached to the fuel filter
assembly. Fuel is forced through the fuel filter ele-
ment and then enters the Fuel Pump/Gear Pump,
which is attached to the rear of the fuel injection
pump. The Fuel Pump/Gear Pump is a low-pressure
pump and produce pressures ranging from 551.5 kpa
(80 psi) to 1241 kpa (180) psi. Fuel then enters the
fuel injection pump. Low pressure fuel is then sup-
plied to the FCA (Fuel Control Actuator).
The FCA is an electronically controlled solenoid
valve. The ECM controls the amount of fuel that
enters the high-pressure pumping chambers by open-
ing and closing the FCA based on a demanded fuel
pressure. The FPS (Fuel Pressure Sensor) on the fuel
rail provides the actual fuel pressure. When the
actuator is opened, the maximum amount of fuel is
being supplied to the fuel injection pump. Any fuel
that does not enter the injection pump is directed to
the cascade overflow valve. The cascade overflow
valve regulates how much excess fuel is used for
lubrication of the pump and how much is returned to
the tank through the drain manifold.
Fuel entering the injection pump is pressurized to
between 300-1600 bar (4351-23206 psi) by three
radial pumping chambers. The pressurized fuel is
then supplied to the fuel rail.
DIAGNOSIS AND TESTING - FUEL INJECTION
PUMP TIMING
With the Bosch injection pump, there are no
mechanical adjustments needed or necessary to
accomplish fuel injection timing. All timing and fuel
adjustments are electrically made by the engine
mounted Engine Control Module (ECM).
Fig. 6 POWER DISTRIBUTION CENTER LOCATION
1 - CLIP
2 - BATTERY
3 - TRAY
4 - NEGATIVE CABLE
5 - POSITIVE CABLE
6 - CLIP
7 - FENDER INNER SHIELD
8 - POWER DISTRIBUTION CENTER
DRFUEL DELIVERY - DIESEL 14 - 53
FUEL HEATER RELAY (Continued)

REMOVAL
CAUTION: Cleanliness cannot be overemphasized
when handling or replacing diesel fuel system com-
ponents. This especially includes the fuel injectors,
high-pressure fuel lines and fuel injection pump.
Very tight tolerances are used with these parts. Dirt
contamination could cause rapid part wear and pos-
sible plugging of fuel injector nozzle tip holes. This
in turn could lead to possible engine misfire.
Always wash/clean any fuel system component
thoroughly before disassembly and then air dry.
Cap or cover any open part after disassembly.
Before assembly, examine each part for dirt, grease
or other contaminants and clean if necessary. When
installing new parts, lubricate them with clean
engine oil or clean diesel fuel only.
(1) Disconnect both negative battery cables at both
batteries. Cover and isolate ends of both cables.
(2) Remove intake manifold air intake tube (above
injection pump) and its rubber connector hose (Fig.
7).
(3) Remove accessory drive belt.
(4) Thoroughly clean the rear of injection pump,
and attachment points for its 3 fuel lines (Fig. 8).
Also clean the opposite ends of these same 3 lines at
their attachment points.
(5) Disconnect Fuel Control Actuator (FCA) electri-
cal connector at rear of injection pump (Fig. 9).
CAUTION: Whenever a fuel line fitting is connected
to a secondary fitting, always use a back-up wrench
on the secondary fitting. Do not allow the second-
ary fitting to rotate.
(6) Remove fuel line (injection pump-to-fuel pres-
sure limiting valve).
(7) Remove fuel line (injection pump-to-fuel rail).
Use back-up wrench on fitting at fuel pump.
(8) Remove fuel line (injection pump-to-fuel filter
housing).
(9) Remove fuel pump drive gear access cover
(plate) with a 3/8º drive ratchet. Plate is threaded to
timing gear cover (Fig. 10).
(10) Remove fuel pump drive gear mounting nut
and washer.
(11) Attach C3428B, or L4407A (or equivalent)
gear puller (Fig. 11) to pump drive gear with 2 bolts,
and separate gear from pump (a keyway is not used
on this particular injection pump). Leave drive gear
hanging loose within timing gear cover.
(12) Remove 3 injection pump mounting nuts (Fig.
12), and remove pump from engine.
Fig. 7 INTAKE TUBE AND CONNECTING HOSE
1 - MANIFOLD ABOVE HEATERS
2 - RUBBER CONNECTING HOSE
3 - METAL INTAKE TUBE
4 - CLAMPS (2)
Fig. 8 OVERFLOW VALVE
1 - BANJO BOLTS
2 - PUMP MOUNTING NUTS (3)
3 - FUEL INJECTION PUMP
4 - CASCADE OVERFLOW VALVE
14 - 54 FUEL DELIVERY - DIESELDR
FUEL INJECTION PUMP (Continued)

INSTALLATION
CAUTION: Cleanliness cannot be overemphasized
when handling or replacing diesel fuel system com-
ponents. This especially includes the fuel injectors,
high-pressure fuel lines and fuel injection pump.
Very tight tolerances are used with these parts. Dirt
contamination could cause rapid part wear and pos-
sible plugging of fuel injector nozzle tip holes. This
in turn could lead to possible engine misfire.
Always wash/clean any fuel system component
thoroughly before disassembly and then air dry.
Cap or cover any open part after disassembly.
Before assembly, examine each part for dirt, grease
or other contaminants and clean if necessary. When
installing new parts, lubricate them with clean
engine oil or clean diesel fuel only.
(1) Inspect pump mounting surfaces at pump and
mounting flange for nicks, cuts or damage. Inspect
o-ring surfaces for nicks, cuts or damage.
(2) Clean injection pump mounting flange at gear
housing. Also clean front of injection pump.
(3) Install new rubber o-ring into machined groove
(Fig. 12) at pump mounting area.
(4) Apply clean engine oilto injection pump
o-ring only.
The machined tapers on both injection pump
shaft and injection pump gear must be abso-
lutely dry, clean and free of any dirt or oil film.
Fig. 9 FUEL CONTROL ACTUATOR
1 - ACTUATOR MOUNTING BOLTS
2 - FCA (FUEL CONTROL ACTUATOR)
3 - ACTUATOR ELECTRICAL CONNECTOR
Fig. 10 PUMP DRIVE GEAR ACCESS COVER
1 - FRONT TIMING GEAR COVER
2 - GEAR ACCESS PLATE (COVER)
3 - SQUARE DRIVE (FOR COVER REMOVAL/INSTALLATION)
Fig. 11 DRIVE GEAR REMOVAL
1 - FRONT TIMING GEAR COVER
2 - GEAR PULLER TOOL
DRFUEL DELIVERY - DIESEL 14 - 55
FUEL INJECTION PUMP (Continued)

This will ensure proper gear-to-shaft tighten-
ing.
(5) Clean pump gear and pump shaft at machined
tapers with an evaporative type cleaner such as
brake cleaner.
(6) Position injection pump to mounting flange on
gear housing while aligning injection pump shaft
through back of injection pump gear.
(7) After pump is positioned flat to mounting
flange, install 3 pump mounting nuts and tighten
finger tight only.Do not attempt a final tightening
at this time.Do not attempt to tighten (pull)
pump to gear housing using mounting nuts.
Damage to pump or gear cover may occur. The
pump must be positioned flat to its mounting
flange before attempting to tighten 3 mounting
nuts.
(8) To prevent damage or cracking of components,
install and tighten nuts in the following sequence:
(a) Install injection pump shaft washer and nut
to pump shaft. Tighten nutfinger tight only.
(b) Do preliminary (light) tightening of injection
pump shaft nut.
(c) Tighten 3 injection pump mounting nuts to
24 N´m (18 ft. lbs.).(d) Do a final tightening of pump shaft nut to
105 N´m (77 ft. lbs.).
(9) Install drive gear access cover (plate) using a
3/8º drive ratchet. Plate is threaded to timing gear
cover. Tighten to 8 N´m (71 in. lbs.) torque.
(10) Install fuel line (injection pump-to-pressure
limiting valve). Tighten bolts to 24 N´m (18 ft. lbs.)
torque.
(11) Install fuel line (injection pump-to-fuel rail).
(a) Tighten fitting at fuel pump to 37 N´m (27 ft.
lbs.) torque. Use a back-up wrench.
(b) Tighten fitting at fuel rail to 37 N´m (27 ft.
lbs.) torque.
(12) Install fuel line (injection pump-to-fuel filter
housing). Tighten to 24 N´m (18 ft. lbs.) torque.
(13) Connect Fuel Control Actuator (FCA) electri-
cal connector to rear of injection pump.
(14) Install intake manifold air intake tube (above
injection pump). Tighten clamps.
(15) Install accessory drive belt.
(16) Install cooling fan shroud.
(17) Install cooling fan assembly.
(18) Connect both negative battery cables to both
batteries.
(19) Check system for fuel or engine oil leaks.
Fig. 12 FUEL INJECTION PUMP REMOVAL/INSTALLATION
1 - PUMP DRIVE GEAR NUT
2 - WASHER
3 - PUMP DRIVE GEAR
4 - RUBBER O-RING
5 - FUEL INJECTION PUMP6 - PUMP MOUNTING NUTS (3)
7 - PUMP MOUNTING STUDS (3)
8 - O-RING MACHINED GROOVE
9 - FRONT TIMING GEAR HOUSING
14 - 56 FUEL DELIVERY - DIESELDR
FUEL INJECTION PUMP (Continued)

INSTALLATION
Engine Mounted Sensor :
The APPS is serviced (replaced) as one assembly
including the lever, brackets and sensor. The APPS is
calibrated to its mounting bracket.
(1) Snap electrical connector into bottom of sensor.
(2) Position APPS assembly to engine and install 6
bolts. Tighten bolts to 24 N´m (18 ft. lbs.) torque.
(3) Connect wiring harness clip at bottom of
bracket.
(4) Refer to Group 21, Transmission for transmis-
sion control cable installation procedures.
(5) Install speed control cable into mounting
bracket. Be sure pinch tabs have secured cable.
(6) Install throttle cable into mounting bracket. Be
sure pinch tabs have secured cable.
(7) Connect throttle cable at lever (snaps on).
(8) Connect speed control cable to lever by pushing
cable connector rearward onto lever pin while hold-
ing lever forward.
(9) Install cable cover.
(10) Connect both negative battery cables to both
batteries.
(11) If necessary, use DRB IIItScan Tool to erase
any Diagnostic Trouble Codes (DTC's) from ECM.Battery Tray Mounted Sensor :
(1) Install Accelerator Pedal Position Sensor
(APPS) cable to accelerator pedal. Refer to Accelera-
tor Pedal Removal / Installation.
(2) Connect electrical connector to APPS.
(3) If necessary, connect cable to APPS lever ball
socket (snaps on).
(4) Snap APPS cable cover closed.
(5) Position APPS assembly to bottom of battery
tray and install 3 bolts. Refer to Torque Specifica-
tions.
(6) Install wheelhouse liner. Refer to Body.
(7) Perform the following procedure:
(a) Connect negative battery cables to both bat-
teries.
(b) Turn key switch ON, but do not crank
engine.
(c) Leave key switch ON for a minimum of 10
seconds. This will allow ECM to learn electrical
parameters.
(8) If necessary, use DRB IIItScan Tool to erase
any Diagnostic Trouble Codes (DTC's) from ECM.
CAMSHAFT POSITION
SENSOR
DESCRIPTION
The Camshaft Position Sensor (CMP) on the 5.9L
diesel engine is located below the fuel injection
pump. It is bolted to the back of the timing gear
housing.
OPERATION
The diesel Camshaft Position Sensor (CMP) con-
tains a hall effect device. A rotating target wheel
(tonewheel) for the CMP is located on the camshaft
gear. This hall effect device detects notches located
on the back side of the camshaft gear. As the cam-
shaft gear rotates, the notches pass the tip of the
CMP.
When the leading edge of the notch passes the tip
of the CMP, the following occurs: The interruption of
magnetic field causes the voltage to switch high
resulting in a signal of approximately 5 volts.
When the trailing edge of the notch passes the tip
of the CMP, the following occurs: The change of the
magnetic field causes the signal voltage to switch low
to 0 volts.
The CMP (Fig. 8) provides a signal to the Engine
Control Module (ECM) at all times when the engine
is running. The ECM uses the CMP information pri-
marily on engine start-up. Once the engine is run-
ning, the ECM uses the CMP as a backup sensor for
engine speed. The Crankshaft Position Sensor (CKP)
Fig. 7 APPS CABLE (OFF ENGINE MOUNTING)
1 - APPS LEVER
2 - BALL SOCKET
3 - SWING-DOWN DOOR
4 - CABLE CLIP
5 - CABLE
DRFUEL INJECTION - DIESEL 14 - 71
ACCELERATOR PEDAL POSITION SENSOR (Continued)

is the primary engine speed indicator for the engine
after the engine is running.
REMOVAL
The Camshaft Position Sensor (CMP) on the 5.9L
diesel engine is located below the fuel injection
pump. It is bolted to the back of the timing gear
housing (Fig. 9).
(1) Disconnect electrical connector at CMP sensor
(Fig. 9).
(2) Remove sensor mounting bolt.
(3) Carefully twist sensor from timing gear hous-
ing.
(4) Check condition of sensor o-ring.
INSTALLATION
(1) Clean out machined hole in back of timing gear
housing (cover).
(2) Apply a small amount of engine oil to sensor
o-ring.
(3) Install sensor into timing gear housing (cover)
with a slight rocking action. Do not twist sensor into
position as damage to o-ring may result.
CAUTION: Before tightening sensor mounting bolt,
be sure sensor is completely flush to back of timingchain housing (cover). If sensor is not flush, dam-
age to sensor mounting tang may result.
(4) Install mounting bolt and tighten. Refer to
Torque Specifications.
(5) Connect electrical connector to sensor.
CRANKSHAFT POSITION
SENSOR
DESCRIPTION
The Crankshaft Position Sensor (CKP) on the die-
sel engine is attached at the front / left side of the
engine next to the engine harmonic balancer (crank-
shaft damper).
OPERATION
The Crankshaft Position Sensor (CKP) is the pri-
mary engine speed indicator for the engine after the
engine is running (Fig. 10). The CKP contains a hall
effect device. A rotating, notched target wheel (tone-
wheel) for the CKP is located on the engine harmonic
balancer (Fig. 11). This hall effect device detects
notches located on the tonewheel. As the tonewheel
rotates, the notches pass the tip of the CKP.
Fig. 8 5.9L DIESEL CMP
1 - CMP
2 - FUEL INJECTION PUMP (BOTTOM)
3 - ELECTRONIC CONTROL MODULE (ECM)
4 - ECM ELEC. CONNECTOR
5 - CMP ELEC. CONNECTOR
6 - CMP MOUNTING BOLT
7 - BACK OF TIMING GEAR HOUSING
Fig. 9 5.9L DIESEL CMP
1 - CMP
2 - FUEL INJECTION PUMP (BOTTOM)
3 - ELECTRONIC CONTROL MODULE (ECM)
4 - ECM ELEC. CONNECTOR
5 - CMP ELEC. CONNECTOR
6 - CMP MOUNTING BOLT
7 - BACK OF TIMING GEAR HOUSING
14 - 72 FUEL INJECTION - DIESELDR
CAMSHAFT POSITION SENSOR (Continued)

When the leading edge of the tonewheel notch
passes the tip of the CKP, the following occurs: The
interruption of magnetic field causes the voltage to
switch high resulting in a signal of approximately 5
volts.
When the trailing edge of the tonewheel notch
passes the tip of the CKP, the following occurs: The
change of the magnetic field causes the signal voltage
to switch low to 0 volts.
The Camshaft Position Sensor (CMP) also provides
a signal to the Engine Control Module (ECM) at all
times when the engine is running. The ECM uses
this CMP information primarily on engine start-up.
Once the engine is running, the ECM uses the CMP
as a backup sensor for engine speed.
REMOVAL
(1) Raise and support vehicle
(2) Disconnect electrical connector at CKP sensor
(Fig. 12).
(3) Remove 1 sensor mounting bolt.
(4) Remove CKP sensor.
INSTALLATION
(1) Position and install CKP sensor to engine.
(2) Install 1 sensor mounting bolt and tighten to 9
N´m (80 in. lbs.) torque.(3) Install electrical connector to CKP sensor (Fig.
12).
Fig. 10 5.9L DIESEL CKP
1 - ENGINE HARMONIC BALANCER
2 - FRONT OF TIMING GEAR COVER
3 - CKP MOUNTING BOLT
4 - ELEC. CONNECTOR
5 - CKP SENSOR
6 - NOTCHES
Fig. 11 CKP NOTCHED TONEWHEEL
1 - ENGINE HARMONIC BALANCER
2 - NOTCHED TONEWHEEL
3 - FRONT OF CRANKSHAFT
Fig. 12 5.9L DIESEL CKP
1 - ENGINE HARMONIC BALANCER
2 - FRONT OF TIMING GEAR COVER
3 - CKP MOUNTING BOLT
4 - ELEC. CONNECTOR
5 - CKP SENSOR
6 - NOTCHES
DRFUEL INJECTION - DIESEL 14 - 73
CRANKSHAFT POSITION SENSOR (Continued)