2003 DODGE RAM engine

STANDARD PROCEDURES - CLEANING FUEL
SYSTEM PARTS
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.
Fig. 1 DIESEL FUEL SYSTEM COMPONENTS
1 - ENGINE COOLANT TEMPERATURE (ECT) SENSOR 14 - FUEL SUPPLY LINE (LOW-PRESSURE, TO ENGINE)
2 - THROTTLE LEVER BELLCRANK AND APPS (ACCELERATOR
PEDAL POSITION SENSOR)15 - FUEL RETURN LINE CONNECTION (TO FUEL TANK)
3 - INTAKE MANIFOLD AIR HEATER/ELEMENTS 16 - FUEL DRAIN TUBE
4 - FUEL PRESSURE SENSOR 17 - OIL PRESSURE SENSOR
5 - FUEL LIMITING VALVE 18 - ENGINE CONTROL MODULE (ECM)
6 - HIGH-PRESSURE FUEL LINES 19 - FUEL INJECTION PUMP
7 - FUEL HEATER 20 - CRANKSHAFT POSITION (ENGINE SPEED) SENSOR
8 - HIGH-PRESSURE FUEL INJECTOR RAIL 21 - CAMSHAFT POSITION SENSOR (CMP)
9 - FUEL HEATER TEMPERATURE SENSOR (THERMOSTAT) 22 - FUEL CONTROL ACTUATOR (FCA)
10 - FUEL FILTER/WATER SEPARATOR 23 - CASCADE OVERFLOW VALVE
11 - FUEL TRANSFER (LIFT) PUMP
12 - FUEL DRAIN MANIFOLD
13 - DRAIN VALVE
14 - 58 FUEL DELIVERY - DIESELDR
FUEL DELIVERY - DIESEL (Continued)

STANDARD PROCEDURE - FUEL SYSTEM
PRIMING
A certain amount of air becomes trapped in the
fuel system when fuel system components on the
supply and/or high-pressure side are serviced or
replaced. Fuel system priming is accomplished using
the electric fuel transfer (lift) pump.
Servicing or replacing fuel system components usu-
ally will not require fuel system priming.
The fuel transfer (lift) pump is self-priming: When
the key is first turned on (without cranking engine),
the pump operates for approximately 2 seconds and
then shuts off. The pump will also operate for up to25 seconds after the starter is quickly engaged, and
then disengaged without allowing the engine to start.
The pump shuts off immediately if the key is on and
the engine stops running.
(1) Turn key to CRANK position and quickly
release key to ON position before engine starts. This
will operate fuel transfer pump for approximately 25
seconds.
(2) If the engine does not start after 25 seconds,
turn key OFF. Repeat previous step until engine
starts.
(3) Fuel system priming is now completed.
(4) Attempt to start engine. If engine will not
start, proceed to following steps.When engine does
start, it may run erratically and be noisy for a
few minutes. This is a normal condition.
CAUTION: Do not engage the starter motor for more
than 30 seconds at a time. Allow two minutes
between cranking intervals.
(5) Perform previous fuel priming procedure steps
using fuel transfer pump. Be sure fuel is present at
fuel tank.
(6) Crank the engine for 30 seconds at a time to
allow fuel system to prime.
WARNING: THE FUEL INJECTION PUMP SUPPLIES
EXTREMELY HIGH FUEL PRESSURE TO EACH INDI-
VIDUAL INJECTOR THROUGH THE HIGH-PRES-
SURE LINES. FUEL UNDER THIS AMOUNT OF
PRESSURE CAN PENETRATE THE SKIN AND
CAUSE PERSONAL INJURY. WEAR SAFETY GOG-
GLES AND ADEQUATE PROTECTIVE CLOTHING.
DO NOT LOOSEN FUEL FITTINGS WHILE ENGINE
IS RUNNING.
WARNING: ENGINE MAY START WHILE CRANKING
STARTER MOTOR.
Fig. 2 FUEL INJECTORS
1 - SOLENOID CONNECTIONS
2 - ROCKER HOUSING
3 - FUEL INJECTOR
4 - PASSTHROUGH CONNECTOR
DRFUEL DELIVERY - DIESEL 14 - 59
FUEL DELIVERY - DIESEL (Continued)

FUEL FILTER / WATER
SEPARATOR
DESCRIPTION
The fuel filter/water separator assembly is located
on left side of engine above starter motor. The assem-
bly also includes the fuel heater and Water-In-Fuel
(WIF) sensor, and fuel transfer pump.
OPERATION
The fuel filter/water separator protects the fuel
injection pump by removing water and contaminants
from the fuel. The construction of the filter/separator
allows fuel to pass through it, but helps prevent
moisture (water) from doing so. Moisture collects at
the bottom of the canister.
Refer to the maintenance schedules for the recom-
mended fuel filter replacement intervals.
For draining of water from canister, refer to Fuel
Filter/Water Separator Removal/Installation section.A Water-In-Fuel (WIF) sensor is attached to side of
canister. Refer to Water-In-Fuel Sensor Description/
Operation.
The fuel heater is installed into the top of the fil-
ter/separator housing. Refer to Fuel Heater Descrip-
tion/Operation.
REMOVAL
Refer to maintenance schedules in this manual for
recommended fuel filter replacement intervals.
Draining water from fuel filter/water separa-
tor housing:
The housing drain valve (Fig. 3) or (Fig. 4) serves
two purposes. One is topartiallydrain filter hous-
ing of excess water. The other is tocompletelydrain
housing for fuel filter, drain valve, heater element, ,
water-in-fuel sensor replacement or transfer pump
replacement.
The filter housing should be partially drained
whenever water-in-fuel warning lamp remains illumi-
nated. (Note that lamp will be illuminated for
approximately two seconds when ignition key is ini-
tially placed in ON position for a bulb check).
(1) A drain hose (Fig. 3) or (Fig. 4) is located at
bottom of drain valve. Place drain pan under drain.
(2)With engine not running,rotate drain valve
handle rearward to OPEN (DRAIN) position. Hold
drain valve open until all water and contaminants
have been removed and clean fuel exits.
(3) If drain valve, fuel heater element or Water-In-
Fuel (WIF) sensor is being replaced, drain housing
completely. Dispose of mixture in drain pan according
to applicable regulations.
(4) After draining operation, push valve handle
forward to CLOSE position.
(5)Fuel Filter Replacement:The fuel filter is
located inside of the fuel filter housing.
(a) Clean all debris from around canister.
(b) Remove filter lid (Fig. 5) using a socket.
Attach socket to large hex on top of lid (Fig. 5).
Rotate counter-clockwise for removal. Remove
o-ring.
(c) Remove filter element by twisting element
sideways from filter lid.
(6)Water-In-Fuel (WIF) Sensor Replacement:
The WIF sensor is located on the side of the fuel fil-
ter housing (Fig. 3) or (Fig. 4).
(a) Disconnect electrical connector at sensor.
(b) Clean area around sensor.
(c) Remove sensor by rotating counter-clockwise.
(d) Check condition of sensor o-ring. Replace if
damaged.
(7)Fuel Heater Element Replacement:The
heater element is located in the fuel filter housing
(Fig. 3) or (Fig. 4).
(a) Remove fuel filter. See previous steps.
FUEL INJECTOR TUBE (CONNECTOR) REMOVER -
#9015
SPANNER WRENCH (FUEL TANK MODULE
REMOVAL/INSTALLATION) - #6856
ENGINE ROTATING (BARRING) TOOL - #7471B
(ALSO PART OF KIT #6860)
DRFUEL DELIVERY - DIESEL 14 - 61
FUEL DELIVERY - DIESEL (Continued)

(b) Disconnect electrical connector.
(c) Remove two T-15 Torx head mounting screws
from fuel heater element.
(d) Remove fuel filter cover and filter element.
(e) Remove fuel heater.
(8)Drain Valve Replacement:The drain valve
assembly is located on the side of the fuel filter hous-
ing (Fig. 3) or (Fig. 4).
(a) Disconnect drain hose from the fuel drain
valve.
(b) Remove 4 drain valve mounting screws (T-15
Torx head).
(c) Remove drain valve from filter housing.
INSTALLATION
Refer to maintenance schedules for recommended
fuel filter replacement intervals.
(1) Thoroughly clean inside of filter housing, filter
cap and all related components.
(2)Fuel Filter:
(a)The engine has a self-priming low-pres-
sure fuel system. Refer to Standard Proce-
dures-Fuel System Priming.
(b) Install new o-ring to canister lid and lubri-
cate o-ring with 30W oil.
Fig. 3 FILTER HOUSING (EARLY)
1 - FILTER HOUSING
2 - FUEL HEATER AND THERMOSTAT
3 - FUEL HEATER MOUNTING SCREWS
4 - FUEL HEATER ELEC. CONNECTOR
5 - DRAIN VALVE
6 - DRAIN VALVE MOUNTING SCREWS
7 - DRAIN HOSE
8 - WIF SENSOR
9 - WIF SENSOR ELEC. CONNECTOR
Fig. 4 FILTER HOUSING (LATE)
1 - FILTER HOUSING
2 - FUEL HEATER AND THERMOSTAT
3 - FUEL HEATER MOUNTING SCREWS
4 - FUEL HEATER ELEC. CONNECTOR
5 - WIF SENSOR
6 - WIF SENSOR ELEC. CONNECTOR
7 - DRAIN HOSE
8 - DRAIN VALVE MOUNTING SCREWS
9 - DRAIN VALVE
Fig. 5 FILTER COVER (LID)
1 - FILTER COVER
2 - ATTACH SOCKET HERE
14 - 62 FUEL DELIVERY - DIESELDR
FUEL FILTER / WATER SEPARATOR (Continued)

(c) Position new element to canister lid. Place
this assembly into canister by rotating clockwise.
(d) Tighten cap to 34 N´m (25 ft. lbs.) torque. Do
not overtighten cap.
(3)Water-In-Fuel (WIF) Sensor:
(a) Install new o-ring seal to WIF sensor.
(b) Apply a light film of clean diesel oil to o-ring
seal.
(c) Install sensor into housing.
(d) Tighten sensor to 4.5 N´m (39 in. lbs.) torque.
(e) Connect electrical connector to WIF sensor.
(4)Fuel Heater Element:
(a) Install fuel heater into fuel filter housing.
(b) Install fuel heater thermostat into fuel filter
housing.
(c) Install fuel heater mounting screws and
tighten to 1-1.5 N´m torque.
(d) Connect electrical connector to fuel heater
thermostat.
(e) Install new filter cover O-ring onto fuel filter
housing cover and lubricate with 30W oil.
(f) Tighten fuel filter housing cover (lid) to 34
N´m (25 ft. lbs.).
(5)Drain Valve:
(a) Install 2 new o-rings to valve and filter hous-
ing.
(b) Lubricate with silicon grease.
(c) Install fuel drain valve.
(d) Install 4 mounting screws and tighten to
1±1.5 N´m (8±13 in. lbs.) torque.
(e) Connect drain hose to drain valve.
(6) Start engine and check for leaks.
FUEL HEATER
DESCRIPTION
The fuel heater assembly is located on the side of
the fuel filter housing (Fig. 3) or (Fig. 4).
The heater/element assembly is equipped with a
temperature sensor (thermostat) that senses fuel
temperature. This sensor is attached to the fuel heat-
er/element assembly.
OPERATION
The fuel heater is used to prevent diesel fuel from
waxing during cold weather operation.
When the temperature is below 45  8 degrees F,
the temperature sensor allows current to flow to the
heater element warming the fuel. When the temper-
ature is above 75  8 degrees F, the sensor stops cur-
rent flow to the heater element.
Battery voltage to operate the fuel heater element
is supplied from the ignition switch and through the
fuel heater relay. Also refer to Fuel Heater Relay.The fuel heater element and fuel heater relay
are not computer controlled.
The heater element operates on 12 volts, 300 watts
at 0 degrees F.
DIAGNOSIS AND TESTING - FUEL HEATER
The fuel heater is used to prevent diesel fuel from
waxing during cold weather operation.
NOTE: The fuel heater element, fuel heater relay
and fuel heater temperature sensor are not con-
trolled by the Engine Control Module (ECM), or the
Powertrain Control Module (PCM).
A malfunctioning fuel heater can cause a wax
build-up in the fuel filter/water separator. Wax
build-up in the filter/separator can cause engine
starting problems and prevent the engine from rev-
ving up. It can also cause blue or white fog-like
exhaust. If the heater is not operating in cold tem-
peratures, the engine may not operate due to fuel
waxing.
The fuel heater assembly is located on the side of
fuel filter housing.
The heater assembly is equipped with a built-in
fuel temperature sensor (thermostat) that senses fuel
temperature. When fuel temperature drops below 45
degrees   8 degrees F, the sensor allows current to
flow to built-in heater element to warm fuel. When
fuel temperature rises above 75 degrees   8 degrees
F, the sensor stops current flow to heater element
(circuit is open).
Voltage to operate fuel heater element is supplied
from ignition switch, through fuel heater relay (also
refer to Fuel Heater Relay), to fuel temperature sen-
sor and on to fuel heater element.
The heater element operates on 12 volts, 300 watts
at 0 degrees F. As temperature increases, power
requirements decrease.
A minimum of 7 volts is required to operate fuel
heater. The resistance value of heater element is less
than 1 ohm (cold) and up to 1000 ohms warm.
TESTING
(1) Disconnect electrical connector from thermostat
(Fig. 3) or (Fig. 4).
Ambient temperature must be below circuit close
temperature, If necessary, induce this ambient tem-
perature by placing ice packs on thermostat to pro-
duce an effective ambient temperature below circuit
close temperature. For first check of thermostat you
can hear click of thermostat when circuit closes.
Measure resistance across two pins. Operating
range is 0.3 Ð 0.45 Ohms.
(2) If resistance is out of range, remove thermostat
and check resistance across terminal connections of
DRFUEL DELIVERY - DIESEL 14 - 63
FUEL FILTER / WATER SEPARATOR (Continued)

heater. The heater can be check at room tempera-
ture. Operating range is 0.3 Ð 0.45 Ohms.
(3) Replace heater if resistance is not within oper-
ating range.
(4) If heater is within operating range, replace
heater thermostat.
REMOVAL
REMOVAL/INSTALLATION
The fuel heater/element/sensor assembly is located
inside of the fuel filter housing. Refer to Fuel Filter/
Water Separator Removal/Installation for procedures.
FUEL HEATER RELAY
DESCRIPTION
The fuel heater relay is located in Power Distribu-
tion Center (PDC) (Fig. 6). Refer to label on inside of
PDC cover for relay location.
OPERATION
Battery voltage to operate the fuel heater element
is supplied from the ignition switch through the fuel
heater relay.The fuel heater element and fuel
heater relay are not computer controlled.
REMOVAL
The fuel heater relay is located in the Power Dis-
tribution Center (PDC) (Fig. 7). Refer to label under
PDC cover for relay location.
(1) Remove PDC cover.
(2) Remove relay from PDC.(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. 7). 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
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
Fig. 7 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
14 - 64 FUEL DELIVERY - DIESELDR
FUEL HEATER (Continued)

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 FAC (Fuel Control Actuator).
The FAC 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 FAC 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 overflow 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 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).
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.
8).
(3) The Engine Control Module (ECM) is mounted
to left side of engine (Fig. 9). Remove 5 ECM mount-ing bolts and position ECM for injection pump
removal.Do not disconnect wiring connectors
from ECM.
(4) Remove cooling fan shroud.
(5) Remove cooling fan assembly.
(6) Remove accessory drive belt.
(7) Thoroughly clean the rear of injection pump,
and attachment points for its 3 fuel lines (Fig. 10).
Also clean the opposite ends of these same 3 lines at
their attachment points.
(8) Disconnect Fuel Control Actuator (FCA) electri-
cal connector at rear of injection pump (Fig. 11).
(9) Remove fuel line (injection pump-to-overflow
valve).
(10) Remove fuel line (injection pump-to-fuel rail).
(11) Remove fuel line (injection pump-to-fuel filter
housing).
(12) Remove fuel pump drive gear access cover
(plate) with a 1/2 inch drive ratchet. Plate is
threaded to timing gear cover (Fig. 12).
(13) Remove fuel pump drive gear mounting nut
and washer.
(14) Attach C3428B, or L4407A (or equivalent)
gear puller (Fig. 13) 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.
(15) Remove 3 injection pump mounting nuts (Fig.
14), and remove pump from engine.
Fig. 8 INTAKE TUBE AND CONNECTING HOSE
1 - MANIFOLD ABOVE HEATERS
2 - RUBBER CONNECTING HOSE
3 - METAL INTAKE TUBE
4 - CLAMPS (2)
DRFUEL DELIVERY - DIESEL 14 - 65
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. 14) at pump mounting area.
Fig. 14 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 COVER
Fig. 13 DRIVE GEAR REMOVAL
1 - FRONT TIMING GEAR COVER
2 - GEAR PULLER TOOL
DRFUEL DELIVERY - DIESEL 14 - 67
FUEL INJECTION PUMP (Continued)