
(e) Connect electrical connector to WIF sensor.
(f) Install fuel filter. Refer to previous steps.
(4)Fuel Heater Element:
(a) Do not install fuel filter until heater element
is installed.
(b) Position heater element into filter housing
(fingers downward). Lock fingers into housing.
(c) Install new o-ring to electrical connector
(where connector passes through filter housing).
Apply a light film of clean diesel oil to o-ring seal.
Press this connector into filter housing until it
snaps into heater element.
(d) Install temperature sensor housing and 2
mounting screws to fuel filter housing.
(e) Connect electrical connector.
(f) Install fuel filter. Refer to previous steps.
(5)Drain Valve:
(a) Install 2 new o-rings to valve and filter hous-
ing.
(b) Apply a light film of clean diesel oil to both
seals.
(c) Position valve to filter housing.
(d) Install 4 mounting screws and tighten to 3±5
N´m (30±40 in. lbs.) torque.
(e) Connect drain hose to drain valve.
(f) Install fuel filter. Refer to previous steps.
(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. 9).
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 4568 degrees F,
the temperature sensor allows current to flow to the
heater element warming the fuel. When the temper-
ature is above 7568 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 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
the fuel filter housing (Fig. 10).
The heater assembly is equipped with a built-in
fuel temperature sensor (thermostat) that senses fuel
temperature. When fuel temperature drops below 45
degrees68 degrees F, the sensor allows current to
flow to the built-in heater element to warm the fuel.
When fuel temperature rises above 75 degrees68
degrees F, the sensor stops current flow to the heater
element (circuit is open).
Fig. 9 Fuel Heater Location
1 - FUEL HEATER AND TEMP. SENSOR
2 - FUEL FILTER/WATER SEPARATOR
3 - FUEL HEATER ELECTRICAL CONNECTOR
14 - 62 FUEL DELIVERY - DIESELBR/BE
FUEL FILTER / WATER SEPARATOR (Continued)

Voltage to operate the fuel heater element is sup-
plied from the ignition switch, through the fuel
heater relay (also refer to Fuel Heater Relay), to the
fuel temperature sensor and on to the fuel heater ele-
ment.
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 the
fuel heater. The resistance value of the heater ele-
ment is less than 1 ohm (cold) and up to 1000 ohms
warm.
TESTING
(1) Disconnect electrical connector at sensor (Fig.
10).
Turn key to ON position. 12 volts should be
present at red wire. If not, check fuel heater relay
and related wiring. Refer to Relay TestÐFuel Heater.
If OK, proceed.
Turn key OFF. Check black wire in connector for
ground continuity with an ohmmeter. If continuity is
not present, correct open ground circuit. This test can
also be performed with a voltmeter by backprobing
black wire with it connected to sensor. Reconnect
electrical connector and turn key ON. Voltage drop
should not exceed 2 volts (2 volts lower than checked
at 12V+ connector). If voltage is lower, check for dirtyor corroded ground connection and repair. If OK, pro-
ceed.
(2) With electrical connector disconnected at sen-
sor and key OFF, check electrical/mechanical opera-
tion of fuel temperature sensor. Proceed to next step:
(3) Using an ohmmeter, check for continuity across
two terminals in electrical connector at side of sen-
sor. Sensor circuit should be open if fuel temperature
has risen above 75 degrees68 degrees F. Sensor cir-
cuit should be closed if fuel temperature has dropped
below 45 degrees68 degrees F. If not, replace fuel
heater assembly. This same test can also be per-
formed using a voltmeter, with key ON, and by back-
probing connector.
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. 11). 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.
Fig. 10 Fuel Heater Location
1 - FUEL HEATER AND TEMP. SENSOR
2 - FUEL FILTER/WATER SEPARATOR
3 - FUEL HEATER ELECTRICAL CONNECTOR
Fig. 11 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
BR/BEFUEL DELIVERY - DIESEL 14 - 63
FUEL HEATER (Continued)

(5) Clean pump gear and pump shaft at machined
tapers (Fig. 34) with an evaporative type cleaner
such as brake cleaner.
Keyway Installation:
(6) The pump/gear keyway has an arrow and a
3±digit number stamped at top edge (Fig. 33). Posi-
tion keyway into pump shaft witharrow pointed to
rear of pump.Also be sure 3±digit number stamped
to top of keyway is same as 3±digit number stamped
to injection pump data plate (Fig. 35). If wrong key-
way is installed, a diagnostic trouble code may be
set.
(7) Position pump assembly to mounting flange on
gear cover while aligning injection pump shaft
through back of injection pump gear. When installing
pump, dowel (Fig. 34) on mounting flange must align
to hole in front of pump.
(8) After pump is positioned flat to mounting
flange, install four 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 cover 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 mounting nuts.
(9) To prevent damage or cracking of components,
tighten nuts/bolts in the following sequence:
(a) Install injection pump shaft washer and nut
to pump shaft. Tighten nutfinger tight only.
(b) Install 2 rear/lower pump mounting bolts
finger tight only.(c) Do preliminary tightening of injection pump
shaft nut to 30 N´m (15±22 ft. lbs.) torque.This is
not the final torque.
(d) Tighten 4 pump mounting nuts to 43 N´m
(32 ft. lbs.) torque.
(e) Tighten 2 rear/lower pump bracket-to-pump
bolts 24 N´m (18 ft. lbs.) torque.
(f) Do final tightening of injection pump shaft
nut to 170 N´m (125 ft. lbs.) torque. Use barring
tool to prevent engine from rotating when tighten-
ing gear.
(10) Install canister (Fig. 24) to gear cover.
(11) Install crankcase vent hose (Fig. 24) to canis-
ter and install hose clamp.
(12) Using new gaskets, install fuel return line
and overflow valve to side of injection pump (Fig. 23).
Tighten overflow valve to 24 N´m (18 ft. lbs.) torque.
(13)
Using new gaskets, install fuel supply line to
side of injection pump and top of fuel filter housing (Fig.
23). Tighten banjo bolts to 24 N´m (18 ft. lbs.) torque.
(14)Install all high-pressure fuel lines, intake air
tube, accelerator pedal position sensor, air intake hous-
ing, engine oil dipstick tube, wiring clips, electrical
cables at intake heaters and engine lifting bracket.
Refer to High-Pressure Fuel Line Removal/Installation.
All of these items are covered in this procedure.
Fig. 34 Injection Pump Installation
1 - DOWEL
2 - PUMP
3 - PUMP SHAFT TAPER
4 - INJECTION PUMP GEAR TAPER
Fig. 35 Injection Pump Data Plate Location
1 - PUMP DATA PLATE
14 - 72 FUEL DELIVERY - DIESELBR/BE
FUEL INJECTION PUMP (Continued)

The transfer pump is self-priming: When the key is
first turned on (without cranking engine), the pump
will operate for approximately 2 seconds and then
shut off. The pump will also operate for up to 25 sec-
onds after the starter is engaged, and then disen-
gaged and the engine is not running. The pump
shuts off immediately if the key is on and the engine
stops running.
The fuel volume of the transfer pump will always
provide more fuel than the fuel injection pump
requires. Excess fuel is returned from the injection
pump through an overflow valve. The valve is located
on the side of the injection pump (Fig. 52). It is also
used to connect the fuel return line to the side of the
injection pump. This valve opens at approximately 97
kPa (14 psi) and returns fuel to the fuel tank
through the fuel return line.
DIAGNOSIS AND TESTING - FUEL TRANSFER
PUMP PRESSURE
The following tests will include: pressures
tests of fuel transfer pump (engine running and
engine cranking), a pressure drop test of fuel
filter, a test for supply side restrictions, and a
test for air in fuel supply side.
Fig. 50 Fuel Transfer Pump Location
1 - OIL PRESSURE SENSOR
2 - PUMP BRACKET NUTS (3)
3 - SUPPORT BRACKET BOLT
4 - BANJO BOLT (REAR)
5 - FUEL SUPPLY LINE
6 - ELECTRICAL CONNECTOR
7 - BANJO BOLT (FRONT)
8 - FUEL TRANSFER PUMP
Fig. 51 Engine Control Module (ECM) Location
1 - ENGINE CONTROL MODULE (ECM)
2 - HEX HEADED BOLT
3 - 50-WAY CONNECTOR
4 - FUEL TRANSFER PUMP
5 - MOUNTING BOLTS (3)
Fig. 52 Injection Pump Overflow Valve Location
1 - FUEL SUPPLY LINE
2 - FUEL RETURN LINE
3 - BANJO BOLT (TEST PORT FITTING)
4 - OVERFLOW VALVE
5 - BANJO FITTING
14 - 80 FUEL DELIVERY - DIESELBR/BE
FUEL TRANSFER PUMP (Continued)

Refer to Fuel Transfer Pump Description/Operation
for an operational description of transfer pump.
The fuel transfer (lift) pump is located on left side
of engine and above starter motor (Fig. 53).
An improperly operating fuel transfer pump, a
plugged or dirty fuel filter, or a defective overflow
valve can cause low engine power, excessive white
smoke and/or hard engine starting.
Before performing following tests, inspect fuel sup-
ply and return lines for restrictions, kinks or leaks.
Fuel leaking from pump casing indicates a leaking
pump which must be replaced.
Pressure Test:Because the transfer pump is oper-
ating at two different pressure cycles (engine running
and engine cranking), two different pressure tests
will be performed.
(1) Remove protective cap at inlet test port (Fig.
54). Clean area around cap/fitting before cap
removal.
(2) Remove protective cap at outlet test port (Fig.
55). Clean area around cap/fitting before cap
removal.
(3) Install Special Fuel Pressure Test Gauge 6828
(or equivalent) to fitting at inlet test port (Fig. 54).(4) To prevent engine from starting, remove fuel
system relay (fuel injection pump relay). Relay is
located in Power Distribution Center (PDC). Refer to
label under PDC cover for relay location.
Fig. 53 Fuel Transfer Pump Location
1 - OIL PRESSURE SENSOR
2 - PUMP BRACKET NUTS (3)
3 - SUPPORT BRACKET BOLT
4 - BANJO BOLT (REAR)
5 - FUEL SUPPLY LINE
6 - ELECTRICAL CONNECTOR
7 - BANJO BOLT (FRONT)
8 - FUEL TRANSFER PUMP
Fig. 54 Fuel Pressure Test Port Fitting (Inlet)
1 - FUEL PRESSURE TEST PORT (INLET)
2 - FUEL FILTER/WATER SEPARATOR
Fig. 55 Fuel Pressure Test Port Fitting (Outlet)
1 - FUEL PRESSURE TEST PORT (OUTLET)
BR/BEFUEL DELIVERY - DIESEL 14 - 81
FUEL TRANSFER PUMP (Continued)

(5) Using key, crank engine over while observing
gauge. Pressure should be 5±7 psi.
(6) Re-install fuel system relay to PDC.
(7) Start engine and record fuel pressure. Pressure
should be aminimumof 69 kPa (10 psi) at idle
speed.
(8) Because fuel pump relay was removed, a Diag-
nostic Trouble Code (DTC) may have been set. After
testing is completed, and relay has been installed,
use DRB scan tool to remove DTC.
Pressure Drop Test:
(9) Shut engine off and remove test gauge from
inlet port test fitting. Re-attach 6828 test gauge to
outlet port (Fig. 55). Start engine and record fuel
pressure. Pressure should not be more than 34 kPa
(5 psi) lower than inlet port pressure test. If so,
replace fuel filter.
Fuel Supply Restriction Test:
Due to very small vacuum specifications, the DRB
scan tool along with the Periphal Expansion Port
(PEP) Module and 0±15 psi transducer must be used.
(10) Verify transfer pump pressure is OK before
performing restriction test.
(11) Locate and disconnect fuel supply line quick-
connect fitting at left-rear of engine (Fig. 56). After
disconnecting line, plastic clip will remain attached
to metal fuel line at engine. Carefully remove clip
from metal line. Snap same clip into fuel supply
hose.
(12) Install Special Rubber Adapter Hose Tool
6631 (3/8º) into ends of disconnected fuel supply line.(13) Install transducer from PEP module to brass
ªTº fitting on tool 6631.
(14) Hook up DRB scan tool to transducer.
WARNING: DO NOT STAND IN LINE WITH THE
COOLING FAN FOR THE FOLLOWING STEPS.
(15) Start engine and record vacuum reading with
engine speed at high-idle (high-idle means engine
speed is at 100 percent throttle and no load). The
fuel restriction testMUSTbe done with engine speed
at high-idle.
(16) If vacuum reading islessthan 6 in/hg. (0±152
mm hg.), test is OK. If vacuum reading ishigher
than 6 in/hg. (152 mm hg.), restriction exists in fuel
supply line or in fuel tank module. Check fuel supply
line for damage, dents or kinking. If OK, remove
module and check module and lines for blockage.
Also check fuel pump inlet filter at bottom of module
for obstructions.
Testing For Air Leaks in Fuel Supply Side:
(17) A 3±foot section of 3/8º I.D. clear tubing is
required for this test.
(18) Using a tire core valve removal tool, carefully
remove core valve from inlet fitting test port.
(19) Attach and clamp the 3/8ºclear hose to fitting
nipple.
(20) Place other end of hose into a large clear con-
tainer. Allow hose to loop as high as possibleabove
test port.
(21) The fuel transfer pump can be put into a 25
second run (test) mode if key is quickly turned to
crank position and released back to run position
without starting engine.
To prevent engine from starting in this test, first
remove fuel system relay (fuel injection pump relay).
Relay is located in Power Distribution Center (PDC).
Refer to label under PDC cover for relay location.
Because fuel pump relay was removed, a Diagnos-
tic Trouble Code (DTC) may have been set. After test-
ing is completed, and relay has been installed, use
DRB scan tool to remove DTC.
(22) Allow air to purge from empty hose before
examining for air bubbles. Air bubbles should not be
present.
(23) If bubbles are present, check for leaks in sup-
ply line to fuel tank.
(24) If supply line is not leaking, remove fuel tank
module and remove filter at bottom of module (filter
snaps to module). Check for leaks between supply
nipple at top of module, and filter opening at bottom
of module. Replace module if necessary.
(25) After performing test, install core back into
test fitting. Before installing protective cap, be sure
fitting is not leaking.
Fig. 56 Fuel Return and Supply Line Quick-Connect
Locations
1 - FUEL RETURN LINE
2 - QUICK-CONNECT FITTINGS
3 - FUEL SUPPLY LINE
14 - 82 FUEL DELIVERY - DIESELBR/BE
FUEL TRANSFER PUMP (Continued)

(1) Clean area around overflow valve and fuel
return line at injection pump before removal.
(2) Remove valve from pump and banjo fitting.
(3) Discard old sealing gaskets.
INSTALLATION
The overflow valve (pressure relief valve) is located
at the outside of fuel injection pump (Fig. 60). It con-
nects the fuel return line (banjo fitting) to the pump.
The valve has no internal serviceable parts and must
be replaced as an assembly. Two sealing gaskets are
used. One gasket is located between pump and banjo
fitting. The other is located between the banjo fitting
and end of valve.
(1) Install new sealing gaskets to valve.
(2) Install valve through banjo fitting and into
pump.
(3) Tighten to 30 N´m (24 ft. lbs.) torque.
WATER IN FUEL SENSOR
DESCRIPTION
The WIF sensor is located on the side of the fuel
filter/water separator canister (Fig. 61).
OPERATION
The sensor sends an input to the Engine Control
Module (ECM) when it senses water in the fuel filter/
water separator. As the water level in the filter/sep-
arator increases, the resistance across the WIF
sensor decreases. This decrease in resistance is sent
as a signal to the ECM and compared to a high
water standard value. Once the value reaches 30 to
40 kilohms, the ECM will activate the water-in-fuel
warning lamp through CCD bus circuits. This all
takes place when the ignition key is initially put in
the ON position. The ECM continues to monitor the
input at the end of the intake manifold air heater
post-heat cycle.
REMOVAL
The Water-In-Fuel (WIF) sensor is located at the
side of fuel filter/water separator canister. Refer to
Fuel Filter/Water Separator Removal/Installation for
WIF sensor removal/installation procedures.
Fig. 60 Overflow Valve Location
1 - FUEL SUPPLY LINE
2 - FUEL RETURN LINE
3 - BANJO BOLT (TEST PORT FITTING)
4 - OVERFLOW VALVE
5 - BANJO FITTING
Fig. 61 Water-in-Fuel Sensor Location
1 - WATER-IN-FUEL (WIF) SENSOR
2 - FUEL FILTER/WATER SEPARATOR
3 - WIF SENSOR CONNECTOR
BR/BEFUEL DELIVERY - DIESEL 14 - 85
OVERFLOW VALVE (Continued)

(g) If any of these conditions occur, replace injec-
tor.
(2) Thoroughly clean fuel injector cylinder head
bore with special Cummins wire brush tool or equiv-
alent (Fig. 24). Blow out bore hole with compressed
air.
(3) The bottom of fuel injector is sealed to cylinder
head bore with a copper sealing washer (shim) of a
certain thickness. A new shim with correct thickness
must always be re-installed after removing injector.
Measure thickness of injector shim (Fig. 23).Shim
Thickness: 1.5 mm (.060º)
(4) Install new shim (washer) to bottom of injector
(Fig. 22). Apply light coating of clean engine oil to
washer. This will keep washer in place during instal-
lation.
(5) Install new o-ring to fuel injector. Apply small
amount of clean engine oil to o-ring.
(6) Note fuel inlet hole on side of fuel injector. This
hole must be positioned towards injector connector
tube. Position injector into cylinder head bore being
extremely careful not to allow injector tip to touch
sides of bore. Press fuel injector into cylinder head
with finger pressure only.Do not use any tools to
press fuel injector into position. Damage to
machined surfaces may result.
(7) Position fuel injector hold down clamp into
shouldered bolt while aligning slot in top of injector
into groove in bottom of clamp. Tighten opposite
clamp bolt (Fig. 18) to 10 N´m (89 in. lbs.) torque.
(8) Install new o-ring to fuel injector connector
tube. Apply small amount of clean engine oil to
o-ring.
(9) Press injector connector tube into cylinder head
with finger pressure only.Do not use any tools topress tube into position. Damage to machined
surfaces may result.
(10) Connect high-pressure fuel lines. Refer to
High-Pressure Fuel Lines Removal/Installation.The
fuel line fitting torque is very critical.If fitting
is under torqued, the mating surfaces will not seal
and a high-pressure fuel leak will result. If fitting is
over torqued, the connector and injector will deform
and also cause a high-pressure fuel leak. This leak
will be inside cylinder head and will not be visible
resulting in a possible fuel injector miss and low
power.
(11) Install valve cover. (Refer to 9 - ENGINE/
CYLINDER HEAD/CYLINDER HEAD COVER(S) -
INSTALLATION).
(12) (If necessary) install intake manifold air
heater assembly. Refer to Intake Manifold Air Heater
Removal/Installation.
(13) (If necessary) install engine lifting bracket.
Tighten 2 bolts to 77 N´m (57 ft. lbs.) torque.
(14) Connect negative battery cables to both bat-
teries.
(15) Bleed air from high-pressure lines (Refer to 14
- FUEL SYSTEM/FUEL DELIVERY - STANDARD
PROCEDURE).
FUEL INJECTION PUMP
RELAY
DESCRIPTION
The fuel injection pump relay is located in the
Power Distribution Center (PDC). Refer to label
under PDC cover for relay location.
OPERATION
The Engine Control Module (ECM) energizes the
electric fuel injection pump through the fuel injection
pump relay. Battery voltage is applied to the fuel
injection pump relay at all times. When the key is
turned ON, the relay is energized when a 12±volt sig-
nal is provided by the ECM. When energized,
12±volts is supplied to the Fuel Pump Control Mod-
ule. The Fuel Pump Control Module is located on the
top of the fuel injection pump and is non-servicable.
FUEL TEMPERATURE SENSOR
DESCRIPTION
Two different fuel temperature sensors are used.
One of the sensors is located inside of the Bosch
VP44 fuel injection pump and is a non-serviceable
part. The other fuel temperature sensor is located in
the top of the fuel filter housing and is serviceable
(serviceable if replacing the fuel heater).
Fig. 24 Cleaning Cylinder Head Injector BoreÐ
TYPICAL BORE
1 - INJECTOR BORE
2 - WIRE BRUSH
BR/BEFUEL INJECTION - DIESEL 14 - 99
FUEL INJECTOR (Continued)