power DODGE RAM 2002 Service Repair Manual

(22) Remove front bumper (Refer to 13 - FRAMES
& BUMPERS/BUMPERS/FRONT BUMPER -
REMOVAL).
(23) If A/C equipped, disconnect A/C condenser
refrigerant lines.
(24) Disconnect charge air cooler piping.
(25) Remove the two charge air cooler mounting
bolts.
(26) Remove charge air cooler (and A/C condenser
if equipped) from vehicle.
(27) Disconnect engine block heater connector.
(28) Disconnect A/C compressor electrical connec-
tors.
(29) Remove the passenger battery ground cable
from the engine block.
(30) Disconnect power steering pump pressure and
return lines.
(31) Remove accelerator linkage cover.
(32) Leaving all cables attached, remove accelera-
tor pedal position sensor assy. (APPS) (Fig. 4) from
cylinder head bracket and secure out of the way.
(33) Disconnect APPS connector (Fig. 5).
(34) Disconnect vacuum pump supply hose (Fig. 6).
(35) Disconnect the engine harness and ground
cable from the PDC.
(36) Disconnect the fuel supply and return hoses
(Fig. 7).
(37) Remove the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(38) Remove the #5 and #6 cylinder intake and
exhaust rocker arms and pedestals (Fig. 8). Note the
original location for re-assembly.
(39) Loosen but do not remove engine mount
through bolts and nuts.
(40) Attach chain accross engine lift brackets.(41) Lift engine up and out of engine compart-
ment.
(42) Install engine to suitable engine stand.
Fig. 3 Exhaust Pipe Connection at Turbocharger
1 - EXHAUST PIPE
2 - TURBOCHARGER EXHAUST PIPE
Fig. 4 APPS Assembly
1 - LEVER
2 - MOUNTING BOLTS (6)
3 - WIRE HARNESS CLIP
4 - CALIBRATION SCREWS (NO ADJUSTMENT)
5 - APPS ASSEMBLY
Fig. 5 APPS Connector
1 - APPS
2-TAB
3 - PUSH FOR REMOVAL
4 - APPS CONNECTOR
9 - 124 ENGINE 5.9L DIESELBR/BE
ENGINE 5.9L DIESEL (Continued)

(8) Connect the engine harness connector and
ground cable to the PDC.
(9) Connect the vacuum pump supply hose.
(10) Connect the APPS connector (Fig. 5).
(11) Install the APPS assembly bracket to the cyl-
inder head bracket.
(12) Install the throttle linkage cover.
(13) Connect the power steering pressure and
return lines.
(14) Connect the passenger battery ground cable to
the engine block. Tighten the bolt to 77 N´m (57 ft.
lbs.) torque.
(15) Connect the engine block heater connector.
(16) Connect the a/c compressor electrical connec-
tors.
(17) Install the charge air cooler and a/c condenser
(if a/c equipped). Install and tighten the charge air
cooler mounting bolts to 2 N´m (17 in. lbs.) torque.
(18) Connect the charge air cooler piping. Torque
all clamps to 8 N´m (72 in. lbs.) torque.
(19) Connect the a/c refrigerant lines to the a/c
condenser (if equipped).
(20) Install the front bumper (Refer to 13 -
FRAMES & BUMPERS/BUMPERS/FRONT
BUMPER - INSTALLATION).(21) Install the radiator upper support panel.
(22) Install the radiator (Refer to 7 - COOLING/
ENGINE/RADIATOR - INSTALLATION).
(23) Connect the transmission quick-connect oil
cooler lines to the radiator. Push together until an
audible ªclickº is heard. Verify connection by pulling
apart.
(24) Raise vehicle.
(25) Connect a/c compressor suction/discharge hose
(if a/c equipped).
(26) Install the radiator lower hose and clamps.
(27) Install the starter motor (Refer to 8 - ELEC-
TRICAL/STARTING/STARTER MOTOR - INSTAL-
LATION).
(28) Install the transmission and transfer case (if
equipped).
(29) Connect the exhaust pipe to the turbocharger
elbow (Fig. 3). Torque the bolts to 34 N´m (25 ft. lbs.)
torque.
(30) Connect the transmission auxiliary oil cooler
lines (if equipped).
(31) Lower the vehicle
(32) Connect the heater core supply and return
hoses.
(33) Install the cooling fan and shroud at the same
time (Refer to 7 - COOLING/ENGINE/RADIATOR
FAN - INSTALLATION).
(34) Install the coolant recovery bottle to the fan
shroud (Fig. 2) and connect the hose to the radiator
filler neck.
(35) Install the windshield washer bottle to the fan
shroud and connect the pump supply hose and elec-
trical connections.
(36) Install the radiator upper hose and clamps.
(37) Change oil filter and install new engine oil.
(38) Fill cooling system with coolant (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(39) Connect battery negative cables.
(40) Perform the fuel line air bleed procedure
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(41) Start engine and inspect for engine oil, cool-
ant, and fuel leaks.
INSTALLATIONÐCRANKCASE BREATHER
VAPOR CANISTER
(1) Position vapor canister with strap over stud on
engine front cover. Install retaining nut. Tighten nut
10 N´m ( 89 in. lbs.).
(2) If removed, position hose onto crankcase
breather, then position clamp.
(3) Position lower portion of hose into vapor canis-
ter, then install and tighten cap.
Fig. 9 Crankcase Breather Vapor Canister
1 - ENGINE FRONT COVER STUD
2 - STRAP
3 - VAPOR CANISTER
4 - NUT
5 - CAP
6 - CRANKCASE BREATHER
7 - CLAMP
8 - HOSE
9 - 126 ENGINE 5.9L DIESELBR/BE
ENGINE 5.9L DIESEL (Continued)

SPECIFICATIONS
5.9L DIESEL
DESCRIPTION SPECIFICATION
Engine Type In-Line 6 Cyl. Turbo
Diesel
Bore and Stroke 102.0 X 120.0 mm
(4.02 X 4.72 in.)
Displacement 5.9L (359 cu. in.)
Compression Ratio
245 H.P. Version 17.0:1
235 H.P. Version 16.3:1
Horsepower (A/T and 5
Speed M/T)235 @ 2700 rpm
Horsepower (6 Speed M/T
Only)245 @ 2700 rpm
Torque Rating (A/T and 5
Speed M/T)460 ft. lbs. @ 1600 rpm
Torque Rating (6 Speed
M/T Only)505 ft. lbs. @ 1600 rpm
Firing Order 1-5-3-6-2-4
Lubrication System Pressure Feed-Full Flow
With Bypass Valve
Cylinder Block Cast Iron
Crankshaft Induction Hardened
Forged Steel
Cylinder Head Cast Iron With Valve
Seat Inserts
Combustion Chambers High Swirl Bowl
Camshaft Chilled Ductile Iron
Pistons Cast Aluminum
Connecting Rods Cross Rolled Micro Alloy
PISTONS AND CONNECTING RODS
Piston
Skirt Diameter 101.864 ± 101.88 mm
(4.0104 ± 4.011 in.)
Ring Groove Clearance
Intermediate (Max.) 0.095 mm (0.0037 in.)
Oil Control (Max.) 0.085 mm (0.0033 in.)
Piston Pins
Pin Diameter (Min.) 39.990 mm (1.5744 in.)
Bore Diameter (Max.) 40.025 mm (1.5758 in.)
Piston Ring End Gap
DESCRIPTION SPECIFICATION
Top Ring 0.35 ± 0.45 mm
(0.014 ± 0.0177 in.)
Intermediate 0.85 ± 1.15 mm
(0.0334 ± 0.0452 in.)
Oil Control 0.250 ± 0.550 mm
(0.010 ± 0.0215 in.)
Connecting Rods
Pin Bore Diameter (Max.) 40.042 mm (1.5764 in.)
Side Clearance 0.100 ± 0.330 mm
(0.004 ± 0.013 in.)
CYLINDER HEAD
Overall Flatness End to
End (Max.)0.30 mm (0.012 in.)
Overall Flatness Side to
Side (Max.)0.076 mm (0.003 in.)
Intake Valve Seat Angle 30É
Exhaust Valve Seat Angle 45É
Valve Seat Width
(Min.) 1.49 mm (0.059 in.)
(Max.) 1.80 mm (0.071 in.)
Valve Margin (Min.) 0.72 mm (0.031 in.)
OIL PRESSURE
At Idle 69 kPa (10 psi)
At 2,500 rpm 207 kPa (30 psi)
Regulating Valve Opening
Pressure448 kPa (65 psi)
Oil Filter Bypass Pressure
Setting344.75 kPa (50 psi)
TORQUE
TORQUE CHART 5.9L DIESEL ENGINE
DESCRIPTION N´m In. Ft.
Lbs. Lbs.
Connecting RodÐBolts
Step 1 35 Ð 26
Step 2 70 Ð 51
Step 3 100 Ð 73
Cylinder HeadÐBolts
Step 1 80 Ð 59
Step 2 105 Ð 77
Step 3 Verify 105 Ð 77
BR/BEENGINE 5.9L DIESEL 9 - 127
ENGINE 5.9L DIESEL (Continued)

ENGINE DATA PLATE
DESCRIPTION
The engine data plate contains specific information
that is helpful to servicing and obtaining parts for
the engine. The data plate is located on the left side
of the engine, affixed to the gear housing. Informa-
tion that can be found on the data plate includes:
²Date of Engine Manufacture
²Engine Serial Number
²Control Parts List (CPL)
²Engine Rated Horsepower
²Engine Firing Order
²Engine Displacement
²Valve Lash Reset Specifications
If the engine data plate is missing or not legible,
the engine serial number is used for engine identifi-
cation. The engine serial number is stamped on the
right side of the block, on top of the oil cooler cavity
(Fig. 10) .
AIR CLEANER ELEMENT
REMOVAL
Testing Air Cleaner Element using Filter Minder
Do not attempt to unnecessarily remove the
top of the air cleaner housing for air cleaner
element inspection on diesel engines.
The air cleaner (filter) housing is equipped with an
air Filter MinderŸ gauge (Fig. 11). This air flowrestriction gauge will determine when the air cleaner
element is restricted and should be replaced.
The Filter MinderŸ consists of a diaphragm and
calibrated spring sealed inside of a plastic housing
(Fig. 12). A yellow colored disc attached to the dia-
phragm moves along a graduated scale on the side of
the Filter Minder. After the engine has been shut off,
a ratcheting device located within the Filter Minder
will hold the yellow disc at the highest restriction
that the air cleaner element has experienced. A drop
in air pressure due to an air cleaner element restric-
tion moves the diaphragm and the yellow disc will
indicate the size of the air drop.
TEST PLUG - 8442
ADAPTER - 8462
Fig. 10 Engine Serial Number Location
Fig. 11 Filter MinderŸÐLocationÐDiesel Engine
1 - AIR FILTER HOUSING COVER
2 - TURBOCHARGER
3 - AIR INLET TUBE
4 - HOSE CLAMP
5 - HINGE TABS
6 - FILTER MINDER
7 - CLIPS (4)
8 - TUBE ALIGNMENT NOTCHES
BR/BEENGINE 5.9L DIESEL 9 - 129
ENGINE 5.9L DIESEL (Continued)

(7) Apply a bead of MopartSilicone Rubber Adhe-
sive Sealant or equivalent to the gear housing cover
sealing surface.
(8) Install the gear housing cover (Refer to 9 -
ENGINE/VALVE TIMING/GEAR HOUSING COVER
- INSTALLATION).
(9) Install the vibration damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION).
(10) Install the fan support/hub assembly and
torque bolts to 24 N´m (18 ft. lbs.).
(11) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(12) Install the cooling fan (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - INSTALLATION).
(13) Connect battery negative cables.
(14) Start engine and check for oil leaks.
INTAKE MANIFOLD
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove the charge air cooler outlet tube from
the air inlet housing (Fig. 166).
(3) Remove the engine oil dipstick tube mounting
bolt (Fig. 166). Position dipstick tube to the side.
(4) Disconnect the air grid heater power cables at
the cable mounting studs (Fig. 167).
(5) Remove the four (4) air inlet housing mounting
bolts (Fig. 167) and remove the housing from top of
the heater elements.
(6) Remove the intake air grid heater from the
manifold (Fig. 168).
(7) Remove the high pressure fuel lines.(Refer to
14 - FUEL SYSTEM/FUEL DELIVERY/FUEL LINES
- REMOVAL).
(8) Remove the remaining intake manifold cover-
to-cylinder head bolts.
(9) Remove the intake manifold cover and gasket.
Keep the gasket material and any other material out
of the air intake.
(10) Clean the intake manifold cover and cylinder
head sealing surface.
CLEANING
Clean manifold in solvent and blow dry with com-
pressed air.
Clean cylinder block front and rear gasket surfaces
using a suitable solvent.
The plenum pan rail must be clean and dry (free of
all foreign material).
INSPECTION
Inspect manifold for cracks.Inspect mating surfaces of manifold for flatness
with a straightedge.
INSTALLATION
(1) Using a new gasket, install the intake manifold
cover.
(2) Install the cover-to-cylinder head bolts that do
not hold down the high pressure fuel line support
brackets. Tighten the bolts to 24 N´m (18 ft. lbs.)
torque.
(3) Install the high pressure fuel lines (Refer to 14
- FUEL SYSTEM/FUEL DELIVERY/FUEL LINES -
INSTALLATION).
(4) Install the high pressure fuel line support
bracket-to-intake manifold cover bolts and tighten to
24 N´m (18 ft. lbs.) torque.
(5) Using two (2) new gaskets, install the intake
air grid heater and air inlet housing (Fig. 167). Posi-
tion the ground cable and install and tighten the
bolts to 24 N´m (18 ft. lbs.) torque.
(6) Install and tighten the air intake heater power
supply nuts to 14 N´m (120 in. lbs.) torque.
(7) Install the engine oil dipstick tube and mount-
ing bolt (Fig. 166).
Fig. 166 Charge Air Cooler Air Tube
1 - FRONT WIRING CLIP
2 - GROUND CABLE
3 - TUBE BOLT
4 - ENGINE OIL DIPSTICK TUBE
5 - CLAMPS
6 - AIR TUBE (INT. MAN.-TO-INTERCOOLER)
7 - RUBBER HOSE
8 - AIR INTAKE HOUSING
9 - CABLE BRACKET HOUSING
9 - 184 ENGINE 5.9L DIESELBR/BE
OIL PUMP (Continued)

(8) Position the charge air cooler outlet tube onto
the air inlet housing (Fig. 166). Tighten the clamps
to 8 N´m (72 in. lbs.) torque.(9) Perform the fuel system air bleed procedure
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(10) Connect the battery negative cables.
EXHAUST MANIFOLD
REMOVAL
(1) Disconnect the battery negative cables.
(2) Raise vehicle on hoist.
(3) Disconnect the exhaust pipe from the turbo-
charger elbow (Fig. 169) .
(4) Lower vehicle.
(5) Disconnect the turbocharger air inlet hose (Fig.
170) .
(6) Disconnect the turbocharger oil supply line and
the oil drain tube from the turbocharger (Fig. 171) .
(7) Disconnect the charge air cooler inlet pipe from
the turbocharger (Fig. 171) .
(8) Remove the turbocharger and gasket from the
exhaust manifold.
(9) Remove the cab heater return pipe nut from
the exhaust manifold stud. Position the tube out of
the way.
(10) Remove the exhaust manifold-to-cylinder head
bolts and spacers (Fig. 172) .
(11) Remove the exhaust manifold and gaskets
(Fig. 172) .
CLEANING
Clean the cylinder head and exhaust manifold seal-
ing surfaces with a suitable scraper. Use a Scotch-
BriteŸ pad or equivalent.
Fig. 167 Air Inlet Housing
1 - GROUND STRAP
2 - AIR INTAKE HOUSING
3 - HEATER POWER CABLE MOUNTING STUDS
4 - FUEL LINE BRACKET BOLT
5 - HOUSING BOLTS (4)
Fig. 168 Intake Air Grid Heater
1 - AIR HEATER ELEMENTS
2 - LOWER GASKET
3 - BLOCK
4 - UPPER GASKET
Fig. 169 Exhaust Pipe
1 - EXHAUST PIPE
2 - TURBOCHARGER EXHAUST PIPE
BR/BEENGINE 5.9L DIESEL 9 - 185
INTAKE MANIFOLD (Continued)

SPECIFICATIONS
TORQUE
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Adjusting StrapÐBolt 23 Ð 200
Air Heater Power SupplyÐ
Nuts14 Ð 124
Air Inlet HousingÐBolts 24 18 Ð
Cab Heater Supply/Return
LineÐNuts24 18 Ð
Exhaust ClampÐNuts 48 35 Ð
Exhaust Manifold to Cylinder
HeadÐBolts
(Diesel Engine) 43 32 Ð
Exhaust Manifold to Cylinder
HeadÐBolts
(5.9L) 31 23 Ð
Exhaust Manifold to Cylinder
HeadÐBolts
(8.0L) 22 Ð 195
Exhaust Pipe to ManifoldÐ
Bolts31 23 Ð
Generator MountingÐBolts 41 30 Ð
Charge Air Cooler
MountingÐBolts2Ð17
Charge Air Cooler DuctÐ
Nuts8Ð72
Heat ShieldÐNuts and Bolts 11 Ð 100
Turbocharger MountingÐ
Nuts32 24 Ð
Turbocharger Oil Drain
TubeÐBolts24 18 Ð
Turbocharger Oil Supply
LineÐFitting15 Ð 133
Turbocharger V-Band
ClampÐNut9Ð75
CATALYTIC CONVERTER -
3.9L/5.2L/5.9L
DESCRIPTION
The stainless steel catalytic converter is located
under the vehicle, integral to the exhaust pipe(s).
OPERATION
The catalytic converter captures and burns any
unburned fuel mixture exiting the combustion cham-
bers during the exhaust stroke of the engine. This
process aids in reducing emissions output.
REMOVAL
(1) Raise and support vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove clamps and nuts (Fig. 3) (Fig. 4).
(4) Remove the catalytic converter.
Fig. 3 Catalytic Converter and Exhaust Pipe 3.9L,
5.2L and 5.9L Light Duty ( Federal )
1 - BOLT
2 - EXHAUST PIPE W/CONVERTER
3 - NUT
4 - RETAINER
BR/BEEXHAUST SYSTEM 11 - 5
EXHAUST SYSTEM (Continued)

(4) Connect the DRBIIItto the pressure trans-
ducer following the instructions supplied with the
DRB IIIt.
(5) Enter DRBIIItinto pressure reading mode and
test drive vehicle.
(6) The turbocharger boost pressure must be
between 110 - 138 kpa (16 - 20 psi.). If pressure read-
ings are lower than 110 kpa (16 psi.) 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
²Turbocharger damaged (Refer to 11 - EXHAUST
SYSTEM/TURBOCHARGER SYSTEM/TURBO-
CHARGER - INSPECTION)
TURBOCHARGER
DESCRIPTION
The turbocharger is an exhaust-driven super-
charger 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 cylinders, which creates more power during com-
bustion.
The turbocharger assembly consists of four (4)
major component systems (Fig. 19) (Fig. 20) :
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
²Improved operating economy
²Altitude compensation
²Noise reduction.
The turbocharger also uses a wastegate (Fig. 21) ,
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 opensthe valve, diverting some of the exhaust gases away
from the turbine wheel. This limits turbine shaft
speed and air output from the impeller.
Fig. 19 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
Fig. 20 Turbocharger Wastegate Actuator
1 - TURBOCHARGER
2 - DIAPHRAGM
3 - WASTE GATE ACTUATOR
11 - 14 EXHAUST SYSTEMBR/BE
TURBOCHARGER SYSTEM (Continued)

CHARGE AIR COOLER AND
PLUMBING
DESCRIPTION
The charge air system (Fig. 29) 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
preformance can be caused by leaks in the charge air
cooler or it's plumbing. The following procedure out-
lines how to check for leaks in the charge air cooler
system.(1) Loosen clamp and remove turbocharger to air
inlet duct rubber sleeve from turbocharger (Fig. 30).
(2) Insert Special Tool 8442 Adapter into the rub-
ber sleeve. Tighten existing 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 regulated air supply to air fitting on
Special Tool 8442 Adapter. Set air pressure to a Max-
imum of 138 kpa (20 psi).
(4) Using soapy water check the air inlet ducts,
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.
(1) Disconnect the battery negative cables.
(2) Remove the front bumper (Refer to 13 -
FRAMES & BUMPERS/BUMPERS/FRONT
BUMPER - REMOVAL).
(3) Remove the front support bracket.
Fig. 29 Intake Air Circulation
1 - CHARGE AIR COOLER
2 - AIRFILTER
3 - TURBOCHARGER
Fig. 30 AIR INLET DUCT RUBBER SLEEVE
1 - CLAMP
2 - TURBOCHARGER
3 - AIR DUCT RUBBER SLEEVE
4 - AIR INLET DUCT
11 - 18 EXHAUST SYSTEMBR/BE

FUEL DELIVERY - GASOLINE
DESCRIPTION - FUEL DELIVERY SYSTEM
The fuel delivery system consists of:
²the fuel pump module containing the electric
fuel pump, fuel filter/fuel pressure regulator, rollover
valve (certain modules), fuel gauge sending unit (fuel
level sensor) and a separate fuel filter located at bot-
tom of pump module
²fuel tubes/lines/hoses
²quick-connect fittings
²fuel injector rail
²fuel injectors
²fuel tank
²fuel tank filler/vent tube assembly
²fuel tank filler tube cap
²accelerator pedal
²throttle cable
OPERATION - FUEL DELIVERY SYSTEM
Fuel is returned through the fuel pump module
and back into the fuel tank through the fuel filter/
fuel pressure regulator. A separate fuel return line
from the engine to the tank is not used with any gas-
oline powered engine.
The fuel tank assembly consists of: the fuel tank,
fuel pump module assembly, fuel pump module lock-
nut/gasket and fuel tank check valve(s) (refer to 25,
Emission Control System for Fuel Tank Check Valve
information).
A fuel filler/vent tube assembly using a pressure/
vacuum, 1/4 turn fuel filler cap is used. The fuel
filler tube contains a flap door located below the fuel
fill cap.
Also to be considered part of the fuel system is the
evaporation control system. This is designed to
reduce the emission of fuel vapors into the atmo-
sphere. The description and function of the Evapora-
tive Control System is found in 25, Emission Control
Systems.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.
DIAGNOSIS AND TESTING - FUEL PRESSURE
LEAK DOWN TEST
Use this test in conjunction with the Fuel Pump
Pressure Test and Fuel Pump Capacity Test.
Check Valve Operation:The electric fuel pump
outlet contains a one-way check valve to prevent fuel
flow back into the tank and to maintain fuel supply
line pressure (engine warm) when pump is not oper-
ational. It is also used to keep the fuel supply linefull of gasoline when pump is not operational. After
the vehicle has cooled down, fuel pressure may drop
to 0 psi (cold fluid contracts), but liquid gasoline will
remain in fuel supply line between the check valve
and fuel injectors.Fuel pressure that has
dropped to 0 psi on a cooled down vehicle
(engine off) is a normal condition.When the elec-
tric fuel pump is activated, fuel pressure should
immediately(1±2 seconds) rise to specification.
Abnormally long periods of cranking to restart a
hotengine that has been shut down for a short
period of time may be caused by:
²Fuel pressure bleeding past a fuel injector(s).
²Fuel pressure bleeding past the check valve in
the fuel pump module.
(1) Disconnect the fuel inlet line at fuel rail. Refer
to Fuel Tubes/Lines/Hoses and Clamps for proce-
dures. On some engines, air cleaner housing removal
may be necessary before fuel line disconnection.
(2) Obtain correct Fuel Line Pressure Test Adapter
Tool Hose. Tool number 6539 is used for 5/16º fuel
lines and tool number 6631 is used for 3/8º fuel lines.
(3) Connect correct Fuel Line Pressure Test
Adapter Tool Hose between disconnected fuel line
and fuel rail (Fig. 1).
Fig. 1 CONNECTING ADAPTER TOOLÐTYPICAL
1 - VEHICLE FUEL LINE
2 - TEST PORT ªTº
3 - SPECIAL TOOL 6923, 6631, 6541 OR 6539
4 - FUEL PRESSURE TEST GAUGE
5 - FUEL LINE CONNECTION AT RAIL
6 - FUEL RAIL
14 - 2 FUEL DELIVERY - GASOLINEBR/BE