Engine Intake Manifold DODGE RAM 2003 Service Repair Manual

(1) Loosen clamps holding air inlet duct rubber
sleeve to the intake manifold and air inlet duct.
Remove rubber sleeve (Fig. 13).
(2) Position Special Tool 8462 onto air inlet duct
and intake manifold. Using the existing clamps
tighten to 8 N´m (72 in. lbs.).
(3) Install the 3447.5 kPa 500 psi (gray) Pressure
Transducer (part of OT-CH8520 Transducer Kit) into
Special Tool 8462.
(4) Connect the DRB IIItto the pressure trans-
ducer following the instructions supplied with the
DRB IIIt.
(5) Enter DRB IIItinto pressure reading mode
and test drive vehicle.
(6) Full laod boost pressure at rated speed will be
158 - 186 kPa (23 - 27 psi.) depending on engine hp
rating.. If pressure readings are are not within this
range inspect for the following:
²Restricted air inlet system
²Leak in the charge air cooler system (Refer to 11
- EXHAUST SYSTEM/TURBOCHARGER SYSTEM/
CHARGE AIR COOLER AND PLUMBING - DIAG-
NOSIS AND TESTING)
²Turbocharger wastegate broken or misadjusted
²Restricted/high pressure drop across charge air
cooler²Turbocharger damaged (Refer to 11 - EXHAUST
SYSTEM/TURBOCHARGER SYSTEM/TURBO-
CHARGER - INSPECTION)
TURBOCHARGER
DESCRIPTION
The turbocharger is an exhaust-driven supercharger
which increases the pressure and density of the air
entering the engine. With the increase of air entering
the engine, more fuel can be injected into the cylin-
ders, which creates more power during combustion.
The turbocharger assembly consists of four (4)
major component systems (Fig. 14) (Fig. 15) :
²Turbine section
²Compressor section
²Bearing housing
²Wastegate
OPERATION
Exhaust gas pressure and energy drive the tur-
bine, which in turn drives a centrifugal compressor
that compresses the inlet air, and forces the air into
the engine through the charge air cooler and plumb-
ing. Since heat is a by-product of this compression,
the air must pass through a charge air cooler to cool
the incoming air and maintain power and efficiency.
Increasing air flow to the engine provides:
²Improved engine performance
²Lower exhaust smoke density
Fig. 13 INTAKE MANIFOLD TO AIR INLET DUCT
RUBBER SLEEVE
1 - INTAKE MANIFOLD AIR INLET
2 - CLAMPS
3 - AIR INLET DUCT
4 - AIR INLET DUCT RUBBER SLEEVE
Fig. 14 Turbocharger Operation
1 - TURBINE SECTION
2 - EXHAUST GAS
3 - BEARING HOUSING
4 - COMPRESSOR SECTION
5 - INLET AIR
6 - COMPRESSED AIR TO ENGINE
7 - EXHAUST GAS
8 - EXHAUST GAS TO EXHAUST PIPE
DREXHAUST SYSTEM 11 - 11
TURBOCHARGER SYSTEM (Continued)

²Improved operating economy
²Altitude compensation
²Noise reduction.
The turbocharger also uses a wastegate (Fig. 16),
which regulates intake manifold air pressure and
prevents over boosting at high engine speeds. When
the wastegate valve is closed, all of the exhaust gases
flow through the turbine wheel. As the intake mani-
fold pressure increases, the wastegate actuator opens
the valve, diverting some of the exhaust gases away
from the turbine wheel. This limits turbine shaft
speed and air output from the impeller.
The turbocharger is lubricated by engine oil that is
pressurized, cooled, and filtered. The oil is delivered
to the turbocharger by a supply line that is tapped
into the oil filter head. The oil travels into the bear-
ing housing, where it lubricates the shaft and bear-
ings (Fig. 17). A return pipe at the bottom of the
bearing housing, routes the engine oil back to the
crankcase.
The most common turbocharger failure is bearing
failure related to repeated hot shutdowns with inade-
quate ªcool-downº periods. A sudden engine shut downafter prolonged operation will result in the transfer of
heat from the turbine section of the turbocharger to
the bearing housing. This causes the oil to overheat
and break down, which causes bearing and shaft dam-
age the next time the vehicle is started.
Letting the engine idle after extended operation
allows the turbine housing to cool to normal operat-
ing temperature. The following chart should be used
as a guide in determining the amount of engine idle
time required to sufficiently cool down the turbo-
charger before shut down, depending upon the type
of driving and the amount of cargo.
Fig. 15 Turbocharger Wastegate Actuator
1 - TURBOCHARGER
2 - DIAPHRAGM
3 - WASTE GATE ACTUATOR
Fig. 16 Wastegate Operation
1 - SIGNAL LINE
2 - EXHAUST BYPASS VALVE
3 - WASTEGATE
4 - EXHAUST
5 - TURBINE
11 - 12 EXHAUST SYSTEMDR
TURBOCHARGER (Continued)

(3)Pre-lube the turbocharger.Pour 50 to 60 cc
(2 to 3 oz.) clean engine oil in the oil supply line fit-
ting. Carefully rotate the turbocharger impeller by
hand to distribute the oil thoroughly.
(4) Install and tighten the oil supply line to 24
N´m (18 ft. lbs.) torque.
(5) Position the charge air cooler inlet pipe to the
turbocharger. With the clamp in position, tighten the
clamp nut to 11 N´m (95 in. lbs.) torque.
(6) Position the air inlet hose to the turbocharger
(Fig. 18). Tighten the clamp to 11 N´m (95 in. lbs.)
torque.
(7) Raise vehicle on hoist.
(8) Connect the exhaust pipe to the turbocharger
and tighten the bolts to 34 N´m (25 ft. lbs.) torque.
(9) Lower the vehicle.
(10) Connect the battery negative cables.
(11) Start the engine to check for leaks.
CHARGE AIR COOLER AND
PLUMBING
DESCRIPTION
The charge air system (Fig. 23) consists of the
charge air cooler piping, charge air cooler and intake
air grid heater.
The charge air cooler is a heat exchanger that uses
air flow from vehicle motion to dissipate heat from
the intake air. As the turbocharger increases air
pressure, the air temperature increases. Lowering
the intake air temperature increases engine effi-
ciency and power.
OPERATION
Intake air is drawn through the air cleaner and
into the turbocharger compressor housing. Pressur-ized air from the turbocharger then flows forward
through the charge air cooler located in front of the
radiator. From the charge air cooler the air flows
back into the intake manifold.
DIAGNOSIS AND TESTING - CHARGE AIR
COOLER SYSTEM - LEAKS
Low turbocharger boost pressure and low engine
performance can be caused by leaks in the charge air
cooler or it's plumbing. Fuel staining on the exhaust
manifold can also be an indication that there are
leaks in the air system.The following procedure out-
lines how to check for leaks in the charge air cooler
system.
(1) Loosen clamp and remove air inlet hose from
turbocharger.
(2)
Insert Special Tool 9022 Adapter into the turbo-
charger inlet. Tighten tool clamp to 8 N´m (72 in. lbs.).
CAUTION: Do not apply more than 138 kPa (20 psi)
air pressure to the charge air cooler system, sever
damage to the charge air cooler system may occur.
(3) Connect a regulated air supply to air fitting on
Special Tool 9022 Adapter. Set air pressure to a Max-
imum of 138 kPa (20 psi).
(4) Using soapy water check the rubber sleeves,
charge air cooler and intake manifold for leaks.
REMOVAL
WARNING: IF THE ENGINE WAS JUST TURNED
OFF, THE AIR INTAKE SYSTEM TUBES MAY BE
HOT.
Fig. 22 Measure Turbocharger Bearing Radial
Clearance
1 - FEELER GAUGE
Fig. 23 Intake Air Circulation
1 - CHARGE AIR COOLER
2 - AIRFILTER
3 - TURBOCHARGER
DREXHAUST SYSTEM 11 - 15
TURBOCHARGER (Continued)

CAUTION: The left and right fuel rails are replaced
as an assembly. Do not attempt to separate rail
halves at connector tube (Fig. 20). Due to design of
tube, it does not use any clamps. Never attempt to
install a clamping device of any kind to tube. When
removing fuel rail assembly for any reason, be care-
ful not to bend or kink tube.
(1) Remove fuel tank filler tube cap.
(2) Perform Fuel System Pressure Release Proce-
dure.
(3) Remove negative battery cable at battery.
(4) Remove flex tube (air cleaner housing to
engine).
(5) Remove air resonator box at throttle body.
(6) Disconnect all spark plug cables from all spark
plugs and ignition coils. Do not remove cables fromcable routing tray. Note original cable positions while
removing (Fig. 22).
(7) Remove spark plug cable tray from engine by
releasing 4 retaining clips (Fig. 21). Remove tray and
cables from engine as an assembly.
(8) Disconnect electrical connectors at all 8 igni-
tion coils. Refer to Ignition Coil Removal/Installation.
(9) Disconnect fuel line latch clip and fuel line at
fuel rail. A special tool will be necessary for fuel line
disconnection. Refer to Quick-Connect Fittings.
(10) Disconnect electrical connectors at all 8 fuel
injectors. To remove connector refer to (Fig. 17). Push
red colored slider away from injector (1). While push-
ing slider, depress tab (2) and remove connector (3)
from injector. The factory fuel injection wiring har-
ness is numerically tagged (INJ 1, INJ 2, etc.) for
injector position identification. If harness is not
tagged, note wiring location before removal.
(11) Disconnect electrical connectors at all throttle
body sensors.
(12) Remove 4 fuel rail mounting bolts and hold-
own clamps (Fig. 20).
(13) Gently rock and pullleftside of fuel rail until
fuel injectors just start to clear machined holes in
intake manifold. Gently rock and pullrightside of
rail until injectors just start to clear intake manifold
head holes. Repeat this procedure (left/right) until all
injectors have cleared machined holes.
(14) Remove fuel rail (with injectors attached)
from engine.
(15) If fuel injectors are to be removed, refer to
Fuel Injector Removal/Installation.
5.9L V-8
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE (EVEN WITH ENGINE TURNED
OFF). BEFORE SERVICING FUEL RAIL ASSEMBLY,
FUEL SYSTEM PRESSURE MUST BE RELEASED.
To release fuel pressure, refer to Fuel System Pres-
sure Release Procedure found in this group.
CAUTION: The left and right fuel rails are replaced
as an assembly. Do not attempt to separate the rail
halves at the connecting hose (Fig. 24). Due to the
design of this connecting hose, it does use any
clamps. Never attempt to install a clamping device
of any kind to the hose. When removing the fuel rail
assembly for any reason, be careful not to bend or
kink the connecting hose.
(1) Remove negative battery cable at battery.
(2) Remove air cleaner.
(3) Perform fuel pressure release procedure.
(4) Remove throttle body from intake manifold.
Refer to Throttle Body Removal/Installation.
Fig. 19 FUEL RAIL REMOVE/INSTALL - 4.7L V-8
1 - MOUNTING BOLTS (4)
2 - INJ.#7
3 - INJ.#5
4 - QUICK-CONNECT FITTING
5 - INJ.#3
6 - FUEL INJECTOR RAIL
7 - INJ.#1
8 - CONNECTOR TUBE
9 - INJ.#2
10 - INJ.#4
11 - INJ.#6
12 - INJ.#8
13 - PRESSURE TEST PORT CAP
DRFUEL DELIVERY - GAS 14 - 15
FUEL RAIL (Continued)

(5) If equipped with air conditioning, remove the
A-shaped A/C compressor-to-intake manifold support
bracket (three bolts) (Fig. 23).(6) Disconnect electrical connectors at all fuel
injectors. To remove connector refer to (Fig. 17). Push
red colored slider away from injector (1). While push-
ing slider, depress tab (2) and remove connector (3)
from injector. The factory fuel injection wiring har-
ness is numerically tagged (INJ 1, INJ 2, etc.) for
injector position identification. If harness is not
tagged, note wiring location before removal.
(7) Disconnect fuel tube (line) at side of fuel rail.
Refer to Quick-Connect Fittings for procedures,
(8) Remove the remaining fuel rail mounting bolts.
(9) Gently rock and pull theleftfuel rail until the
fuel injectors just start to clear the intake manifold.
Gently rock and pull therightfuel rail until the fuel
injectors just start to clear the intake manifold.
Repeat this procedure (left/right) until all fuel injec-
tors have cleared the intake manifold.
(10) Remove fuel rail (with injectors attached)
from engine.
8.0L V-10
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE EVEN WITH THE ENGINE OFF.
BEFORE SERVICING FUEL RAIL, FUEL SYSTEM
PRESSURE MUST BE RELEASED.
(1) Remove negative battery cable at battery.
(2) Remove air cleaner housing and tube.
(3) Perform fuel pressure release procedure. Refer
to Fuel Delivery System section of this group.
(4) Disconnect throttle body linkage and remove
throttle body from intake manifold. Refer to Throttle
Body removal in this group.
(5) Remove ignition coil pack and bracket assem-
bly (Fig. 25) at intake manifold and right engine
valve cover (four bolts).
(6) Remove upper half of intake manifold. Refer to
Engines for procedures.
(7) Disconnect electrical connectors at all fuel
injectors. To remove connector refer to (Fig. 26). Push
red colored slider away from injector (1). While push-
ing slider, depress tab (2) and remove connector (3)
from injector. The factory fuel injection wiring har-
ness is numerically tagged (INJ 1, INJ 2, etc.) for
injector position identification.
(8) Disconnect fuel line quick-connect fitting at
left-rear end of fuel rail. A special 3/8 inch fuel line
disconnection tool will be necessary.
(9) Remove the six fuel rail mounting bolts from
the lower half of intake manifold (Fig. 27).
(10) Gently rock and pull theleftfuel rail until
the fuel injectors just start to clear the intake mani-
fold. Gently rock and pull therightfuel rail until
the fuel injectors just start to clear the intake mani-
fold. Repeat this procedure (left/right) until all fuel
injectors have cleared the intake manifold.Fig. 20 5.7L FUEL RAIL
1 - FUEL RAIL
2 - MOUNTING BOLT
3 - HOLDOWN CLAMPS
4 - CONNECTOR TUBE
Fig. 21 5.7L SPARK PLUG CABLE ROUTING TRAY
1 - SPARK PLUG CABLES
2 - RETAINING CLIP
3 - SPARK PLUG CABLE ROUTING TRAY
14 - 16 FUEL DELIVERY - GASDR
FUEL RAIL (Continued)

INSTALLATION
3.7L V-6
(1) If fuel injectors are to be installed, refer to Fuel
Injector Removal/Installation.
(2) Clean out fuel injector machined bores in
intake manifold.
(3) Apply a small amount of engine oil to each fuel
injector o-ring. This will help in fuel rail installation.
(4) Position fuel rail/fuel injector assembly to
machined injector openings in cylinder head.
(5) Guide each injector into cylinder head. Be care-
ful not to tear injector o-rings.
(6) Pushrightside of fuel rail down until fuel
injectors have bottomed on cylinder head shoulder.
Pushleftfuel rail down until injectors have bot-
tomed on cylinder head shoulder.
(7) Install 4 fuel rail mounting bolts and tighten.
Refer to torque specifications.
(8) Install 6 ignition coils. Refer to Ignition Coil
Removal/Installation.
(9) Connect electrical connectors to throttle body.
(10) Connect electrical connectors at all fuel injec-
tors. To install connector, refer to (Fig. 17). Push con-
nector onto injector (1) and then push and lock red
colored slider (2). Verify connector is locked to injec-
tor by lightly tugging on connector.
Fig. 25 IGNITION COIL PACK AND MOUNTING
BRACKET - 8.0L V-10
1 - COIL PACKS AND BRACKET
2 - MOUNTING BOLTS (4)
Fig. 26 REMOVE/INSTALL FUEL INJECTOR
CONNECTOR
Fig. 27 FUEL RAIL MOUNTING BOLTS - 8.0L V-10 -
TYPICAL
1 - FUEL RAIL
2 - ELECTRICAL CONNECTOR
3 - MOUNTING BOLTS (6)
4 - INTAKE MANIFOLD LOWER HALF
5 - FUEL PRESSURE TEST PORT
6 - FUEL INJECTORS (10)
14 - 18 FUEL DELIVERY - GASDR
FUEL RAIL (Continued)

(11) Connect necessary vacuum lines to throttle
body.
(12) Install air resonator mounting bracket near
front of throttle body (2 bolts).
(13) Connect fuel line latch clip and fuel line to
fuel rail. Refer to Quick-Connect Fittings.
(14) Install air box to throttle body.
(15) Install air duct to air box.
(16) Connect battery cable to battery.
(17) Start engine and check for leaks.
4.7L V-8
(1) If fuel injectors are to be installed, refer to Fuel
Injector Removal/Installation.
(2) Clean out fuel injector machined bores in
intake manifold.
(3) Apply a small amount of engine oil to each fuel
injector o-ring. This will help in fuel rail installation.
(4) Position fuel rail/fuel injector assembly to
machined injector openings in cylinder head.
(5) Guide each injector into cylinder head. Be care-
ful not to tear injector o-rings.
(6) Pushrightside of fuel rail down until fuel
injectors have bottomed on cylinder head shoulder.
Pushleftfuel rail down until injectors have bot-
tomed on cylinder head shoulder.
(7) Install 4 fuel rail mounting bolts and tighten.
Refer to torque specifications.
(8) Install 8 ignition coils. Refer to Ignition Coil
Removal/Installation.
(9) Connect electrical connectors to throttle body.
(10) Connect electrical connectors at all fuel injec-
tors. To install connector, refer to (Fig. 17). Push con-
nector onto injector (1) and then push and lock red
colored slider (2). Verify connector is locked to injec-
tor by lightly tugging on connector.
(11) Connect necessary vacuum lines to throttle
body.
(12) Install air resonator mounting bracket near
front of throttle body (2 bolts).
(13) Connect fuel line latch clip and fuel line to
fuel rail. Refer to Quick-Connect Fittings.
(14) Install air box to throttle body.
(15) Install air duct to air box.
(16) Connect battery cable to battery.
(17) Start engine and check for leaks.
5.7L V-8
(1) If fuel injectors are to be installed, refer to Fuel
Injector Removal/Installation.
(2) Clean out fuel injector machined bores in
intake manifold.
(3) Apply a small amount of engine oil to each fuel
injector o-ring. This will help in fuel rail installation.
(4) Position fuel rail/fuel injector assembly to
machined injector openings in intake manifold.(5) Guide each injector into intake manifold. Be
careful not to tear injector o-rings.
(6) Pushrightside of fuel rail down until fuel
injectors have bottomed on shoulders. Pushleftfuel
rail down until injectors have bottomed on shoulders.
(7) Install 4 fuel rail holdown clamps and 4 mount-
ing bolts. Refer to Torque Specifications.
(8) Position spark plug cable tray and cable assem-
bly to intake manifold. Snap 4 cable tray retaining
clips into intake manifold.
(9) Install all cables to spark plugs and ignition
coils.
(10) Connect electrical connector to throttle body.
(11) Install electrical connectors to all 8 ignition
coils. Refer to Ignition Coil Removal/Installation.
(12) Connect electrical connector to throttle body.
(13) Connect electrical connectors at all fuel injec-
tors. To install connector, refer to (Fig. 17). Push con-
nector onto injector (1) and then push and lock red
colored slider (2). Verify connector is locked to injec-
tor by lightly tugging on connector.
(14) Connect fuel line latch clip and fuel line to
fuel rail. Refer to Quick-Connect Fittings.
(15) Install air resonator to throttle body (2 bolts).
(16) Install flexible air duct to air box.
(17) Connect battery cable to battery.
(18) Start engine and check for leaks.
5.9L V-8
(1) If fuel injectors are to be installed, refer to Fuel
Injector Removal/Installation.
(2) Apply a small amount of engine oil to each fuel
injector o-ring. This will help in fuel rail installation.
(3) Clean out fuel injector machined bores in
intake manifold.
(4) Position fuel rail/fuel injector assembly to injec-
tor openings on intake manifold.
(5) Guide each injector into intake manifold. Be
careful not to tear injector o-ring.
(6) Push therightfuel rail down until fuel injec-
tors have bottomed on injector shoulder. Push the
leftfuel rail down until fuel injectors have bottomed
on injector shoulder.
(7) Install fuel rail mounting bolts. Refer to Torque
Specifications.
(8) Connect electrical connector to intake manifold
air temperature sensor.
(9) Connect electrical connectors at all fuel injec-
tors. To install connector, refer to (Fig. 17). Push con-
nector onto injector (1) and then push and lock red
colored slider (2). Verify connector is locked to injec-
tor by lightly tugging on connector.
(10) Install fuel tube (line) at side of fuel rail.
Refer to Quick-Connect Fittings for procedures.
(11) Install air cleaner resonator to throttle body.
(12) Connect battery cable to battery.
DRFUEL DELIVERY - GAS 14 - 19
FUEL RAIL (Continued)

(13) Start engine and check for leaks.
8.0L V-10
(1) Apply a small amount of engine oil to each fuel
injector o-ring. This will help in fuel rail installation.
(2) Install injector(s) and injector clip(s) to fuel
rail.
NOTE: The fuel injector electrical connectors on all
10 injectors should be facing to right (passenger)
side of vehicle (Fig. 27).
(3) Position fuel rail/fuel injector assembly to injec-
tor openings on intake manifold.
(4) Guide each injector into intake manifold. Be
careful not to tear injector o-ring.
(5) Push therightfuel rail down until fuel injec-
tors have bottomed on injector shoulder. Push the
leftfuel rail down until fuel injectors have bottomed
on injector shoulder.
(6) Install six fuel rail mounting bolts into lower
half of intake manifold. Tighten bolts to 15 N´m (136
in. lbs.) torque.
(7) Connect electrical connectors at all fuel injec-
tors. To install connector, refer to (Fig. 26). Push con-
nector onto injector (1) and then push and lock red
colored slider (2). Verify connector is locked to injec-
tor by lightly tugging on connector. The injector wir-
ing harness is numerically tagged.
(8) Install upper half of intake manifold. Refer to
Engines for procedures.
(9) Connect main fuel line at fuel rail. Refer to
Quick-Connect Fittings for procedures.
(10) Install ignition coil pack and bracket assem-
bly at intake manifold and right engine valve cover
(four bolts).
(11) Install throttle body to intake manifold. Refer
to Throttle Body Removal / Installation.
(12) Install throttle body linkage to throttle body.
(13) Install air cleaner tube and housing.
(14) Install negative battery cable at battery.
(15) Start engine and check for leaks.
FUEL TANK
DESCRIPTION
The fuel tank is constructed of a plastic material.
Its main functions are for fuel storage and for place-
ment of the fuel pump module, and (if equipped) cer-
tain ORVR components.
OPERATION
All models pass a full 360 degree rollover test
without fuel leakage. To accomplish this, fuel and
vapor flow controls are required for all fuel tank con-
nections.Two check (control) valves are mounted into the
top of the fuel tank. Refer to Fuel Tank Check Valve
for additional information.
An evaporation control system is connected to the
fuel tank to reduce emissions of fuel vapors into the
atmosphere. When fuel evaporates from the fuel
tank, vapors pass through vent hoses or tubes to a
charcoal canister where they are temporarily held.
When the engine is running, the vapors are drawn
into the intake manifold. Certain models are also
equipped with a self-diagnosing system using a Leak
Detection Pump (LDP) and/or an On-Board Refueling
Vapor Recovery (ORVR) system. Refer to Emission
Control System for additional information.
REMOVAL- EXCEPT DIESEL
Fuel Tank Draining
WARNING: THE FUEL SYSTEM MAY BE UNDER
CONSTANT FUEL PRESSURE EVEN WITH THE
ENGINE OFF. THIS PRESSURE MUST BE
RELEASED BEFORE SERVICING FUEL TANK.
Two different procedures may be used to drain fuel
tank: through the fuel fill fitting on tank, or using
the DRBtscan tool. Due to a one-way check valve
installed into the fuel fill opening fitting at the tank,
the tank cannot be drained conventionally at the fill
cap.
The quickest draining procedure involves removing
the rubber fuel fill hose.
As an alternative procedure, the electric fuel pump
may be activated allowing tank to be drained at fuel
rail connection. Refer to DRB scan tool for fuel pump
activation procedures. Before disconnecting fuel line
at fuel rail, release fuel pressure. Refer to the Fuel
System Pressure Release Procedure for procedures.
Attach end of special test hose tool number 6541,
6539, 6631 or 6923 at fuel rail disconnection (tool
number will depend on model and/or engine applica-
tion). Position opposite end of this hose tool to an
approved gasoline draining station. Activate fuel
pump and drain tank until empty.
If electric fuel pump is not operating, fuel must be
drained through fuel fill fitting at tank. Refer to fol-
lowing procedures.
(1) Release fuel system pressure.
(2) Raise vehicle.
(3) Thoroughly clean area around fuel fill fitting
and rubber fuel fill hose at tank.
(4) If vehicle is equipped with 4 doors and a 6 foot
(short) box, remove left-rear tire/wheel.
(5) Loosen clamp (Fig. 28) and disconnect rubber
fuel fill hose at tank fitting. Using an approved gas
holding tank, drain fuel tank through this fitting.
14 - 20 FUEL DELIVERY - GASDR
FUEL RAIL (Continued)

FUEL INJECTOR
DESCRIPTION
An individual fuel injector (Fig. 17) is used for each
individual cylinder.
OPERATION
OPERATION - FUEL INJECTOR
The top (fuel entry) end of the injector (Fig. 17) is
attached into an opening on the fuel rail.
The fuel injectors are electrical solenoids. The
injector contains a pintle that closes off an orifice at
the nozzle end. When electric current is supplied to
the injector, the armature and needle move a short
distance against a spring, allowing fuel to flow out
the orifice. Because the fuel is under high pressure, a
fine spray is developed in the shape of a pencil
stream. The spraying action atomizes the fuel, add-
ing it to the air entering the combustion chamber.
The nozzle (outlet) ends of the injectors are posi-
tioned into openings in the intake manifold just above
the intake valve ports of the cylinder head. The engine
wiring harness connector for each fuel injector is
equipped with an attached numerical tag (INJ 1, INJ
2 etc.). This is used to identify each fuel injector.
The injectors are energized individually in a sequen-
tial order by the Powertrain Control Module (PCM).
The PCM will adjust injector pulse width by switching
the ground path to each individual injector on and off.
Injector pulse width is the period of time that the
injector is energized. The PCM will adjust injector
pulse width based on various inputs it receives.
Battery voltage is supplied to the injectors through
the ASD relay.
The PCM determines injector pulse width based on
various inputs.
OPERATION - PCM OUTPUT
The nozzle ends of the injectors are positioned into
openings in the intake manifold just above the intake
valve ports of the cylinder head. The engine wiring
harness connector for each fuel injector is equipped
with an attached numerical tag (INJ 1, INJ 2 etc.).
This is used to identify each fuel injector with its
respective cylinder number.
The injectors are energized individually in a sequen-
tial order by the Powertrain Control Module (PCM).
The PCM will adjust injector pulse width by switching
the ground path to each individual injector on and off.
Injector pulse width is the period of time that the
injector is energized. The PCM will adjust injector
pulse width based on various inputs it receives.
Battery voltage (12 volts +) is supplied to the injec-
tors through the ASD relay. The ASD relay will shut-
down the 12 volt power source to the fuel injectors if
the PCM senses the ignition is on, but the engine is
not running. This occurs after the engine has not
been running for approximately 1.8 seconds.
The PCM determines injector on-time (pulse width)
based on various inputs.
REMOVAL
(1) Remove fuel rail. Refer to Fuel Injector Rail
Removal.
(2) Disconnect clip(s) that retain fuel injector(s) to
fuel rail (Fig. 18).
Fig. 17 FUEL INJECTOR
1 - FUEL INJECTOR
2 - NOZZLE
3 - TOP (FUEL ENTRY)
Fig. 18 INJECTOR RETAINING CLIP
1 - PLIERS
2 - INJECTOR CLIP
3 - FUEL INJECTOR - TYPICAL
4 - FUEL RAIL - TYPICAL
14 - 32 FUEL INJECTION - GASDR

5.7L V-8
The IAC motor is not serviceable on the 5.7L V-8
engine.
5.9L V-8
The IAC motor is located on the back of the throt-
tle body (Fig. 22).
(1) Remove air resonator box at throttle body.
(2) Disconnect electrical connector from IAC motor.
(3) Remove two mounting bolts (screws) (Fig. 22).
(4) Remove IAC motor from throttle body.
8.0L V-10
The IAC motor is located on the back of the throt-
tle body (Fig. 23).
(1) Remove the air cleaner cover.
(2) Remove the 4 air cleaner housing mounting
nuts and remove housing from throttle body.
(3) Disconnect electrical connector from IAC motor.
(4) Remove two mounting bolts (screw).
(5) Remove IAC motor from throttle body.
INSTALLATION
3.7L V-6
The Idle Air Control (IAC) motor is located on the
side of the throttle body (Fig. 20).
(1) Install IAC motor to throttle body.
(2) Install and tighten two mounting bolts (screws)
to 7 N´m (60 in. lbs.) torque.
(3) Install electrical connector.
(4) Install air resonator to throttle body.
4.7L V-8
The Idle Air Control (IAC) motor is located on the
side of the throttle body (Fig. 21).
(1) Install IAC motor to throttle body.
Fig. 21 IDLE AIR CONTROL MOTOR - 4.7L V-8
1 - THROTTLE BODY
2 - TPS
3 - IAC MOTOR
4 - IAT SENSOR
5 - MOUNTING SCREWS
Fig. 22 IDLE AIR CONTROL MOTOR - 5.9L V-8
1 - MOUNTING SCREWS
2 - IDLE AIR CONTROL MOTOR
Fig. 23 IAC MOTOR - 8.0L V-10
1 - IDLE AIR CONTROL MOTOR
2 - INTAKE MANIFOLD (UPPER HALF)
3 - THROTTLE POSITION SENSOR
4 - THROTTLE BODY
DRFUEL INJECTION - GAS 14 - 35
IDLE AIR CONTROL MOTOR (Continued)