REMOVAL - 8.0L
The TPS is located on the side of the throttle body
(Fig. 48).
(1) Remove air intake tube at air cleaner housing.
(2) Remove the air cleaner cover.
(3) Remove the 4 air cleaner housing mounting
nuts and remove housing from throttle body.
(4) Disconnect TPS electrical connector.
(5) Remove two TPS mounting bolts (Fig. 48).
(6) Remove TPS from throttle body.
INSTALLATION - 3.9L/5.2L/5.9L
The throttle shaft end of the throttle body slides
into a socket in the TPS (Fig. 49). The TPS must be
installed so that it can be rotated a few degrees. If
the sensor will not rotate, install the sensor with the
throttle shaft on the other side of the socket tangs.
The TPS will be under slight tension when rotated.
(1) Install the TPS and two retaining bolts.
(2) Tighten bolts to 7 N´m (60 in. lbs.) torque.
(3) Manually operate the throttle control lever by
hand to check for any binding of the TPS.
(4) Connect TPS electrical connector to TPS.
(5) Install air intake tube.
INSTALLATION - 8.0L
The throttle shaft end of the throttle body slides
into a socket in the TPS (Fig. 50). The TPS must beinstalled so that it can be rotated a few degrees. If
the sensor will not rotate, install the sensor with the
throttle shaft on the other side of the socket tangs.
The TPS will be under slight tension when rotated.
(1) Install the TPS and two retaining bolts.
(2) Tighten bolts to 7 N´m (60 in. lbs.) torque.
(3) Manually operate the throttle control lever by
hand to check for any binding of the TPS.
(4) Connect TPS electrical connector to TPS.
(5) Install air cleaner housing to throttle body.
(6) Install 4 air cleaner housing mounting nuts.
Tighten nuts to 11 N´m (96 in. lbs.) torque.
(7) Install air cleaner housing cover.
(8) Install air intake tube to cover.
Fig. 48 TPS Mounting BoltsÐ8.0L Engine
1 - MOUNTING BOLTS (2)
2 - IDLE AIR CONTROL MOTOR
3 - THROTTLE POSITION SENSOR
4 - THROTTLE BODY
Fig. 49 InstallationÐ3.9L/5.2L/5.9L EnginesÐTypical
1 - THROTTLE BODY
2 - THROTTLE POSITION SENSOR
3 - THROTTLE SHAFT
4 - SOCKET LOCATING TANGS
Fig. 50 InstallationÐTypical Mounting
1 - THROTTLE BODY
2 - THROTTLE POSITION SENSOR
3 - THROTTLE SHAFT
4 - SOCKET LOCATING TANGS
14 - 52 FUEL INJECTION - GASOLINEBR/BE
THROTTLE POSITION SENSOR (Continued)
FUEL DELIVERY - DIESEL
TABLE OF CONTENTS
page page
FUEL DELIVERY - DIESEL
DESCRIPTION...........................54
OPERATION.............................56
DIAGNOSIS AND TESTING.................56
AIR IN FUEL SYSTEM...................56
FUEL SUPPLY RESTRICTIONS............56
STANDARD PROCEDURE..................56
WATER DRAINING AT FUEL FILTER........56
CLEANING FUEL SYSTEM PARTS..........57
AIR BLEED............................57
SPECIFICATIONS........................58
SPECIAL TOOLS.........................59
FUEL FILTER / WATER SEPARATOR
DESCRIPTION...........................59
OPERATION.............................59
REMOVAL..............................60
INSTALLATION...........................61
FUEL HEATER
DESCRIPTION...........................62
OPERATION.............................62
DIAGNOSIS AND TESTING.................62
FUEL HEATER.........................62
REMOVAL..............................63
FUEL HEATER RELAY
DESCRIPTION...........................63
OPERATION.............................63
DIAGNOSIS AND TESTING.................64
FUEL HEATER RELAY...................64
REMOVAL..............................65
INSTALLATION...........................65
FUEL INJECTION PUMP
DESCRIPTION...........................65
OPERATION.............................66
DIAGNOSIS AND TESTING.................66
FUEL INJECTION PUMP TIMING...........66
REMOVAL..............................68
INSTALLATION...........................71
FUEL INJECTION PUMP DATA PLATE
SPECIFICATIONS........................73FUEL LEVEL SENDING UNIT / SENSOR
DESCRIPTION...........................73
OPERATION.............................73
FUEL LINES
DESCRIPTION...........................73
OPERATION.............................74
DIAGNOSIS AND TESTING.................74
HIGH-PRESSURE FUEL LINE LEAK.........74
REMOVAL..............................75
INSTALLATION...........................77
FUEL TANK
DESCRIPTION...........................78
FUEL TANK MODULE
DESCRIPTION...........................78
OPERATION.............................78
REMOVAL..............................78
INSTALLATION...........................79
FUEL TRANSFER PUMP
DESCRIPTION...........................79
OPERATION.............................79
DIAGNOSIS AND TESTING.................80
FUEL TRANSFER PUMP PRESSURE........80
REMOVAL..............................83
INSTALLATION...........................83
OVERFLOW VALVE
DESCRIPTION...........................83
OPERATION.............................83
DIAGNOSIS AND TESTING.................84
OVERFLOW VALVE.....................84
REMOVAL..............................84
INSTALLATION...........................85
WATER IN FUEL SENSOR
DESCRIPTION...........................85
OPERATION.............................85
REMOVAL..............................85
FUEL DRAIN MANIFOLD
DESCRIPTION...........................86
OPERATION.............................86
REMOVAL..............................86
INSTALLATION...........................86
FUEL DELIVERY - DIESEL
DESCRIPTION - DIESEL FUEL DELIVERY
SYSTEM
The fuel system on the Cummins 24 valveÐTurbo
Diesel Engine uses anelectronicfuel injection
pump with three control modules.Also refer to the Powertrain Control Module (PCM)
or Engine Control Module sections.
Some fuel system components are shown in (Fig.
1).
The fuel delivery system consists of the:
²Accelerator pedal
²Air cleaner housing/element
²Fuel drain manifold (passage)
14 - 54 FUEL DELIVERY - DIESELBR/BE
Fig. 1 Fuel System Components - Diesel
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 TRANSFER (LIFT) PUMP
3 - INTAKE MANIFOLD AIR HEATER/ELEMENTS 16 - OIL PRESSURE SENSOR
4 - HIGH-PRESSURE FUEL LINES 17 - FUEL FILTER/WATER SEPARATOR
5 - FUEL HEATER 18 - DRAIN TUBE
6 - FUEL PRESSURE TEST PORT 19 - WATER-IN-FUEL (WIF) SENSOR
7 - MAP (BOOST) SENSOR 20 - ENGINE CONTROL MODULE (ECM)
8 - FUEL INJECTORS 21 - FUEL PRESSURE TEST PORT
9 - FUEL INJECTOR CONNECTOR 22 - CAMSHAFT POSITION SENSOR (CMP)
10 - INTAKE AIR TEMPERATURE (IAT) SENSOR 23 - OVERFLOW VALVE
11 - FUEL DRAIN MANIFOLD 24 - FUEL INJECTION PUMP
12 - DRAIN VALVE 25 - FUEL HEATER TEMPERATURE SENSOR (THERMOSTAT)
13 - FUEL RETURN LINE (TO FUEL TANK)
BR/BEFUEL DELIVERY - DIESEL 14 - 55
FUEL DELIVERY - DIESEL (Continued)
²Fuel filter/water separator
²Fuel heater
²Fuel heater relay
²Fuel transfer (lift) pump
²Fuel injection pump
²Fuel injectors
²Fuel heater temperature sensor
²Fuel tank
²Fuel tank filler/vent tube assembly
²Fuel tank filler tube cap
²Fuel tank module containing the rollover valve,
fuel gauge sending unit (fuel level sensor) and a sep-
arate fuel filter located at bottom of tank module
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 fittings
²Throttle cable
²Water draining
OPERATION
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 120,000 KPA (17,405
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.
DIAGNOSIS AND TESTING - AIR IN FUEL
SYSTEM
Air will enter the fuel system whenever fuel supply
lines, separator filters, injection pump, high-pressure
lines or injectors are removed or disconnected. Air
trapped in the fuel system can result in hard start-
ing, a rough running engine, engine misfire, low
power, excessive smoke and fuel knock. After service
is performed, air must be bled from the system
before starting the engine.Inspect the fuel system from the fuel transfer
pump to the injectors for loose connections. Leaking
fuel is an indicator of loose connections or defective
seals. Air can also enter the fuel system between the
fuel tank and the transfer pump. Inspect the fuel
tank and fuel lines for damage that might allow air
into the system.
For air bleeding, refer to the Air Bleed Procedure.
DIAGNOSIS AND TESTING - FUEL SUPPLY
RESTRICTIONS
LOW-PRESSURE LINES
Fuel supply line restrictions or a defective fuel
transfer pump can cause starting problems and pre-
vent engine from accelerating. The starting problems
include; low power and/or white fog like exhaust.
Test all fuel supply lines for restrictions or block-
age. Flush or replace as necessary. Bleed fuel system
of air once a fuel supply line has been replaced. Refer
to Air Bleed Procedure for procedures.
To test for fuel line restrictions, a vacuum restric-
tion test may be performed. Refer to Fuel Transfer
Pump Pressure Test.
HIGH-PRESSURE LINES
Restricted (kinked or bent) high-pressure lines can
cause starting problems, poor engine performance,
engine mis-fire and white smoke from exhaust.
Examine all high-pressure lines for any damage.
Each radius on each high-pressure line must be
smooth and free of any bends or kinks.
Replace damaged, restricted or leaking high-pres-
sure fuel lines with correct replacement line.
CAUTION: All high-pressure fuel lines must be
clamped securely in place in holders. Lines cannot
contact each other or other components. Do not
attempt to weld high-pressure fuel lines or to repair
lines that are damaged. If line is kinked or bent, it
must be replaced. Use only recommended lines
when replacement of high-pressure fuel line is nec-
essary.
STANDARD PROCEDURES - WATER DRAINING
AT FUEL FILTER
Refer to Fuel Filter/Water Separator removal/in-
stallation for procedures.
14 - 56 FUEL DELIVERY - DIESELBR/BE
FUEL DELIVERY - DIESEL (Continued)
SPECIAL TOOLS
DIESEL FUEL SYSTEMFUEL FILTER / WATER
SEPARATOR
DESCRIPTION
The fuel filter/water separator assembly is located
on left side of engine above starter motor (Fig. 4).
The assembly also includes the fuel heater and
Water-In-Fuel (WIF) sensor.
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.
Spanner Wrench (Fuel Tank Module Removal/
Installation)Ð6856
Engine Barring (Rotating ) ToolÐ7471B (also part of
Kit #6860)
Fuel Injector Pop Pressure AdaptorÐ8301
Fuel Injector RemoverÐ8318
Fuel Injector Tube (Connector) RemoverÐ8324
Fig. 4 Fuel Filter/Water Separator Location
1 - FUEL HEATER AND TEMP. SENSOR
2 - FUEL FILTER/WATER SEPARATOR
3 - FUEL HEATER ELECTRICAL CONNECTOR
BR/BEFUEL DELIVERY - DIESEL 14 - 59
FUEL DELIVERY - DIESEL (Continued)
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. 5) serves two pur-
poses. One is topartiallydrain filter housing of
excess water. The other is tocompletelydrain hous-
ing for fuel filter, drain valve, heater element or
water-in-fuel sensor replacement.
The filter housing should be drained whenever
water-in-fuel warning lamp remains illuminated.
(Note that lamp will be illuminated for approxi-
mately two seconds when ignition key is initially
placed in ON position for a bulb check).
(1) A drain hose is located at bottom of drain valve
(Fig. 5). Place drain pan under drain hose.
(2)With engine not running,pull drain valve
handle upward to OPEN (DRAIN) position (Fig. 5).
Hold drain valve open until all water and contami-
nants have been removed and clean fuel exits drain
hose.
(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
downward to CLOSE position (Fig. 5).
(5)Fuel Filter Replacement:The fuel filter is
located inside of the fuel filter housing (Fig. 6).
(a) Unscrew and remove fuel filter cap at top of
fuel filter housing (Fig. 5). To unscrew, attach tool
to 6±sided hex center of cap. Do not attempt to
loosen cap at outer edge. The fuel filter cap is
designed to remove filter while pulling up on cap.
(b) Remove o-ring (Fig. 6) from filter cap and
discard.
(c) The filter is retained to the cap with a series
of locking fingers. Carefully pry back a few of the
fingers to unlock filter from cap.
(6)Water-In-Fuel (WIF) Sensor Replacement:
The WIF sensor is located on the side of the fuel fil-
ter housing (Fig. 6).
(a) Disconnect electrical connector at sensor
(Fig. 7).
(b) Unscrew sensor from filter housing.
Fig. 5 Water Drain Valve and Drain Hose
1 - FUEL FILTER CAP
2 - DRAIN VALVE HANDLE
3 - DRAIN HOSE
4 - FUEL FILTER/WATER SEPARATOR
Fig. 6 Fuel Filter/Water Separator Components
1 - CAP
2 - O-RING
3 - FUEL FILTER
4 - FUEL HEATER ELEMENT
5 - HOUSING
6 - O-RINGS
7 - DRAIN VALVE
8 - FUEL HEATER THERMOSTAT
9 - WATER-IN-FUEL SENSOR
14 - 60 FUEL DELIVERY - DIESELBR/BE
FUEL FILTER / WATER SEPARATOR (Continued)
(c) Check condition of o-ring.(d) Inspect the 2 WIF sensor probes. Carefully
clean contaminants from sensor probes with a cloth
if necessary. Replace sensor if probes are covered
with contaminants and will not clean up.
(7)Fuel Heater Element Replacement:The
heater element is located in the fuel filter housing
(Fig. 6).
(a) Remove fuel filter. See previous steps.
(b) Disconnect electrical connector from fuel tem-
perature sensor housing at side of fuel filter hous-
ing (Fig. 8).
(c) Remove 2 temperature sensor housing
mounting screws and carefully remove sensor
housing from fuel filter housing.
(d) Pry round wiring connector from fuel filter
housing and heater element. This connector passes
through the fuel filter housing and is plugged
directly into the heater element.
(e) Unlock heater element fingers and pry heater
element from filter housing.
(8)Drain Valve Replacement:The drain valve is
located on the side of the fuel filter housing (Fig. 6).
(a) Disconnect drain hose (Fig. 5) at bottom of
drain valve.
(b) Remove 4 drain valve mounting screws.
(c) Remove drain valve from filter housing.
(d) Remove 2 drain valve o-rings from filter
housing.
INSTALLATION
Refer to maintenance schedules in this manual for
recommended fuel filter replacement intervals.
(1) Thoroughly clean inside of filter housing, filter
cap and all related components.
(2)Fuel Filter:
(a) Fill fuel filter housing with clean diesel fuel.
If filter housing (canister) is not filled with
clean diesel fuel before installation, manual
air bleeding of fuel system may be necessary
(temporary rough engine running may occur).
If necessary, refer to Air Bleed Procedures.
(b) Snap new filter into locking fingers on cap.
Hole in filter should face downward.
(c) Install new o-ring to cap.
(d) Apply a light film of clean diesel oil to cap
o-ring seal.
(e) Load filter and cap into housing.
(f) Tighten cap to 25 ft. lbs. torque. Do not over-
tighten 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 2±3 N´m (15±20 in. lbs.)
torque.
Fig. 7 Water-In-Fuel Sensor
1 - WATER-IN-FUEL (WIF) SENSOR
2 - FUEL FILTER/WATER SEPARATOR
3 - WIF SENSOR CONNECTOR
Fig. 8 Fuel Filter/Water Separator Location
1 - FUEL HEATER AND TEMP. SENSOR
2 - FUEL FILTER/WATER SEPARATOR
3 - FUEL HEATER ELECTRICAL CONNECTOR
BR/BEFUEL DELIVERY - DIESEL 14 - 61
FUEL FILTER / WATER SEPARATOR (Continued)
(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)