1993 CHEVROLET DYNASTY sensor

(12) Remove the fuel hose quick connect fittings
from the fuel rail using an open end wrench to push
in on the plastic ring located on the end of the fit-
tings. Gently pull the fittings from the fuel rail (Fig.
7).
WARNING: WRAP A SHOP TOWEL AROUND
HOSES TO CATCH ANY GASOLINE SPILLAGE.
(13) Remove direct ignition system (DIS) coils and
generator bracket to intake manifold bolt (Fig. 8). (14) Remove intake manifold bolts and rotate man-
ifold back over rear valve cover (Fig. 9). (15) Cover intake manifold with suitable cover
when servicing (Fig. 10). (16) Remove vacuum harness connector from Fuel
Pressure Regulator. (17) Remove fuel tube retainer bracket screw and
fuel rail attaching bolts (Fig. 10). Spread the retainer
bracket to allow fuel tube removal clearance. (18) Remove fuel rail injector wiring clip from the
generator bracket (Fig. 11). (19) Disconnect cam sensor, coolant temperature
sensor, and engine temperature sensors. (20) Remove fuel injector wiring clip from intake
manifold water tube. (21) Remove fuel rail. Be careful not to damage
the rubber injector O-rings upon removal from their
ports (Fig. 12). (22) Remove upper radiator hose, bypass hose and
rear intake manifold hose (Fig. 13). (23) Remove intake manifold bolts. Remove intake
manifold. (24) Remove intake manifold seal retainers screws
(Fig. 14). Remove intake manifold gasket.
INSPECTION
Check for:
² Damage and cracks of each section.
Fig. 7 Quick Connect Fuel Fittings to Fuel Rail
Fig. 8 Ignition Coils
Fig. 9 Intake Manifold Bolts
Fig. 10 Fuel Rail Attaching Bolts
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 21

(7) Put the tip of each injector into their ports.
Push the assembly into place until the injectors are
seated in the ports (Fig. 12). (8) Install the (4) fuel rail attaching bolts and
tighten to 22 N Im (200 in. lbs.) torque (Fig. 10).
(9) Install fuel tube retaining bracket screw and
tighten to 4 N Im (35 in. lbs.) torque (Fig. 10).
(10) Reconnect cam sensor, coolant temperature
sensor and engine temperature sensors (Fig. 11). (11) Install fuel injector harness wiring clips on
the generator bracket and intake manifold water
tube (Fig. 11). (12) Connect fuel pressure regulator vacuum line.
(13) Remove covering on lower intake manifold
and clean surface. (14) Place intake manifold gasket on lower mani-
fold. Put upper manifold into place and install bolts
finger tight. (15) Install the generator bracket to intake mani-
fold bolt and the cylinder head to intake manifold
strut bolts. Do not torque.
(16) Tighten intake manifold bolts to 28 N Im (250
in. lbs.) torque in the sequence shown in (Fig. 9). (17) Tighten generator bracket to intake manifold
bolt to 54 N Im (40 ft. lbs.) torque (Fig. 8).
(18) Tighten the cylinder head to intake manifold
strut bolts to 54 N Im (40 ft. lbs.) torque (Fig. 5).
(19) Connect ground strap, MAP and heated oxy-
gen sensor electrical connectors (Fig. 6). (20) Connect charge temperature sensor electrical
connector (Fig. 5). (21) Connect vacuum harness to intake plenum
(Fig. 5). (22) Using a new gasket, connect the EGR tube
flange to the intake manifold and tighten to 22 N Im
(200 in. lbs.) torque. (23) Clip wiring harness into the hole in the throt-
tle cable bracket. (24) Connect the wiring connectors to the throttle
position sensor TPS and automatic idle speed AIS
motor (Fig. 4). (25) Connect vacuum harness to throttle body (Fig.
4). (26) Install the direct ignition system DIS coils.
Tighten fasteners to 12 N Im (105 in. lbs.) torque
(Fig. 8). (27) Lubricate the ends of the chassis fuel tubes
with 30 wt oil. Connect fuel supply and return hoses
to chassis fuel tube assembly. pull back on the quick
connect fitting to ensure complete insertion (Fig. 7).
(Refer to Fuel Hoses, Clamps and Quick Connect Fit-
tings in Group 14 Fuel Systems). (28) Install throttle cable (Fig. 3).
(29) Connect fuel injector wiring harness.
(30) Install air cleaner and hose assembly (Fig. 2).
(31) Connect negative battery cable. Fill Cooling
System. See Cooling System, Group 7. (32) With the DRBII Scan Tool use ASD Fuel Sys-
tem Test to pressurize system to check for leaks.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) relay will remain ener-
gized for 7 minutes or until the ignition switch is
turned to the OFF position, or Stop All Test is se-
lected.
EXHAUST MANIFOLDS
REMOVAL
(1) Raise vehicle and disconnect exhaust pipe from
rear cowl side exhaust manifold at articulated joint. (2) Separate EGR tube from rear manifold and dis-
connect Heated Oxygen Sensor lead wire (Fig. 16). (3) Remove Generator/Power Steering Support
Strut (Fig. 16). (4) Remove bolts attaching cross-over pipe to man-
ifold (Fig. 16).
Fig. 15 Intake Manifold Gasket Sealing
Fig. 16 EGR Tube, Heated Oxygen Sensor and Generator/Power Steering Strut
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 23

(5) Remove bolts attaching rear manifold to cylin-
der head and remove manifold. (6) Lower vehicle and remove screws attaching
front heat shield to front manifold (Fig. 17). (7) Remove bolts fastening crossover pipe to front
exhaust manifold and nuts fastening manifold to cyl-
inder head. Remove assemblies (Fig. 18).
INSPECTION
Inspect exhaust manifolds for damage or cracks
and check distortion of the cylinder head mounting
surface and exhaust crossover mounting surface with
a straightedge and thickness gauge (Fig. 19).
EXHAUST MANIFOLD
INSTALLATION
(1) Install rear exhaust manifold and tighten at-
taching bolts to 23 N Im (200 in. lbs.) torque.
(2) Attach exhaust pipe to exhaust manifold and
tighten shoulder bolt to 28 N Im (250 in. lbs.) torque.
(3) Attach crossover pipe to exhaust manifold and
tighten bolt to 33 N Im (25 ft. lbs.) torque and connect
heated oxygen sensor lead (Fig. 16). (4) Install EGR Tube and Generator/Power Steer-
ing Strut (Fig. 16). (5) Install front exhaust manifold and attach ex-
haust crossover (Fig. 18). (6) Install front manifold heat shield and tighten
attaching screws to 23 N Im (200 in. lbs.) torque (Fig.
17).
Fig. 17 Heat Shield
Fig. 18 Crossover Pipe
Fig. 19 Check Exhaust Manifold Mounting Surface
11 - 24 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

FUEL DELIVERY SYSTEM INDEX
page page
Chassis Fuel Tubes ...................... 11
Flexible Fuel Components ................... 3
Fuel FilterÐAll Vehicles .................... 9
Fuel Hoses, Clamps, and Quick Connect Fittings . 10
Fuel Pump Assembly ...................... 5
Fuel Pump Module Installation ............... 9
Fuel Pump Module Removal ................. 8
Fuel Pump Pressure TestÐ2.2L/2.5L TBI and 3.0L MPI Engines ........................... 7
Fuel Pump Pressure TestÐAll Except 2.2L/2.5L TBI and 3.0L MPI ....................... 6
Fuel Pump Strainer Service .................. 9 Fuel System Pressure
...................... 6
Fuel System Pressure Release ProcedureÐ 2.2L/2.5L TBI ........................... 4
Fuel System Pressure Release ProcedureÐ3.0L . . 5
Fuel System Pressure Release ProcedureÐExcept 2.2L/2.5L TBI and 3.0L ................... 4
General Information ........................ 3
Identifying Flexible Fuel Components .......... 3
Mechanical Malfunctions .................... 8
Methanol Concentration SensorÐFlexible Fuel AA-Body .............................. 4
Service Precautions for Flexible Fuel Vehicles .... 3
GENERAL INFORMATION
Beginning this model year, Chrysler began produc-
ing AA-Body vehicles designed to operate on a mix-
ture of gasoline and methanol. These automobiles are
referred to as Flexible Fuel vehicles. Flexible fuel vehicles can operate on a mixture of
up to 85 percent methanol, 15 percent unleaded gas-
oline. These vehicles also operate on mixtures con-
taining a lower percentage of methanol or just pure
unleaded gasoline. In many cases, the procedures for servicing flexible
fuel components is identical to gasoline only compo-
nents. Refer to the particular Service Procedure in
this section. If the service procedure for flexible fuel
component differs from a gasoline only component,
the title of each service procedure identifies the ap-
plication.
SERVICE PRECAUTIONS FOR FLEXIBLE FUEL
VEHICLES
Methanol is more toxic than gasoline. Always re-
lease fuel system pressure before servicing fuel sys-
tem components and wear methanol resistant gloves
and eye protection. Avoid breathing methanol vapors or ingesting
methanol. Headaches, dizziness and even uncon-
sciousness could result from breathing these vapors.
Serious injury, blindness and even death could result
from ingesting methanol. Methanol vapors are extremely flammable and can
travel along the ground. Service vehicles in well ven-
tilated areas and avoid ignition sources. Never
smoke while servicing the vehicle. Do not allow methanol to contact skin. Prolonged
contact with methanol can cause dry skin or an al-
lergic skin reaction. Also, prolonged contact could re-
sult in absorption through the skin.
IDENTIFYING FLEXIBLE FUEL COMPONENTS
Flexible Fuel vehicles have unique methanol com-
patible fuel system components. Chrysler identifies
methanol compatible components that could be phys-
ically interchanged with gasoline only parts by color-
ing them green or applying a green label or tag to
them. Even though they may appear physically iden-
tical, components for gasoline only vehicles must not
be used on flexible fuel vehicles.
FLEXIBLE FUEL COMPONENTS
Flexible fuel AA-body vehicles uses many unique
fuel system components. The unique parts are green
in appearance or have a green tag or label attached
to them. While components used on gasoline only ve-
hicles may look similar or identical, they cannot be
used on flexible fuel vehicles. When servicing a com-
ponent, always use an original equipment or equiva-
lent flexible fuel replacement. The fuel system of flexible fuel AA-body vehicles
have the following unique components.
² Fuel pump module
² Fuel level sensor
² Fuel gauge (gauge cluster).
² Fuel tank
² Fuel pressure regulator (including O-rings)
² Fuel rail
² Fuel injectors (including O-rings)
² Fuel tubes
² Fuel filter
² EVAP canister
² Fuel filler cap
² Fuel filler tube
² Pressure relief/Rollover valve
² All fuel system and emission system hoses and
tubes
Ä FUEL SYSTEMS 14 - 3

INSTRUMENT PANEL CLUSTER IDENTIFICATIONÐFLEXIBLE FUEL AA-BODY
Flexible fuel A-Body vehicles use a unique gauge
cluster. To identify the cluster, remove it from the
instrument panel and check the number on the tag
on the top. If the part number matches the number
in the parts book for flexible fuel A-bodies, the vehi-
cle was built with the correct cluster. Refer to Group
8E, Instrument Panel and Gauges, for cluster re-
moval and installation.
METHANOL CONCENTRATION SENSORÐFLEXIBLE
FUEL AA-BODY
The methanol concentration sensor contains a mi-
croprocessor that determines the percentage of gaso-
line and methanol in the fuel system. From the
methanol concentration sensor input, the powertrain
control module (PCM) determines the amount of
methanol in the fuel. The vehicle can operate on a
mixtures up to 85 percent methanol, 15 percent gas-
oline. The methanol concentration sensor output voltages
varies with the percent of methanol in the fuel sys-
tem. The sensor output voltage (input for PCM)
ranges from 0.5 volts for pure gasoline to 4.75 volts
for 85 percent methanol. For two seconds at key ON
when the operator starts the vehicle, the sensor cal-
ibrates the PCM. During the calibration period the
sensor sends 4.45 volts to the PCM as a correction
factor. The methanol concentration sensor has a built-in
shutdown capability. If the sensor shuts down, it de-
faults to the previous learned value (output voltage
based on methanol percentage of fuel). The methanol concentration sensor attaches to a
bracket at the rear of the fuel tank, next to the fuel
filler tube (Fig. 1).
REMOVAL
WARNING: RELEASE FUEL SYSTEM PRESSURE
BEFORE SERVICING FUEL SYSTEM COMPONENTS.
WHEN SERVICING FLEXIBLE FUEL VEHICLES,
WEAR METHANOL RESISTANT GLOVES AND EYE
PROTECTION AND AVOID BREATHING FUMES. DO
NOT ALLOW METHANOL/GASOLINE MIXTURES TO
CONTACT SKIN. SERVICE VEHICLES IN WELL VEN-
TILATED AREAS AND AVOID IGNITION SOURCES.
NEVER SMOKE WHILE SERVICING THE VEHICLE.
Quick connect fittings attach the fuel tubes to the
methanol concentration sensor (Fig. 1) (1) Release fuel system pressure. Refer to the Fuel
System Pressure Release Procedure. (2) Disconnect the fuel tubes from sensor. Refer to
Quick Connect Fittings in this section. (3) Disconnect electrical connector from sensor.
(4) Remove mounting nuts.
INSTALLATION
(1) Place sensor on bracket. Tighten mounting nut.
(2) Attach electrical connector to sensor.
(3) Connect fuel tubes to sensor. Refer to Quick
Connect Fittings in this section.
FUEL SYSTEM PRESSURE RELEASE
PROCEDUREÐEXCEPT 2.2L/2.5L TBI AND 3.0L
WARNING: RELEASE FUEL SYSTEM PRESSURE
BEFORE SERVICING FUEL SYSTEM COMPONENTS.
WHEN SERVICING FLEXIBLE FUEL VEHICLES,
WEAR METHANOL RESISTANT GLOVES AND EYE
PROTECTION AND AVOID BREATHING FUMES. DO
NOT ALLOW METHANOL/GASOLINE MIXTURES TO
CONTACT SKIN. SERVICE VEHICLES IN WELL VEN-
TILATED AREAS AND AVOID IGNITION SOURCES.
NEVER SMOKE WHILE SERVICING THE VEHICLE.
(1) Disconnect negative cable from battery.
(2) Remove fuel filler cap.
(3) Remove the protective cap from the fuel pres-
sure test port on the fuel rail (Fig. 2). (4) Place the open end of fuel pressure release
hose, tool number C-4799-1, into an approved gaso-
line container or a container approved for gasoline/
methanol mixtures. Connect the other end of hose
C-4799-1 to the fuel pressure test port (Fig. 3). Fuel
pressure will bleed off through the hose into the gas-
oline container. Fuel gauge C-4799-A contains hose
C-4799-1.
FUEL SYSTEM PRESSURE RELEASE
PROCEDUREÐ2.2L/2.5L TBI
CAUTION: Before servicing the fuel pump, fuel
lines, fuel filter, throttle body, or fuel injector, re-
lease fuel system pressure.Fig. 1 Methanol Concentration Sensor
14 - 4 FUEL SYSTEMS Ä

FUEL TANKS INDEX
page page
Flexible Fuel Vehicles ..................... 14
Fuel Pump Module ....................... 18
Fuel Reservoir ........................... 18
Fuel System Pressure Release ProcedureÐ 2.2L/2.5L TBI .......................... 15
Fuel System Pressure Release ProcedureÐ3.0L . 15
Fuel System Pressure Release ProcedureÐ Except 2.2L/2.5L TBI and 3.0L ............. 15 Fuel Tank
.............................. 16
Fuel Tank Level Sensor ................... 18
Fuel Tank Pressure Relief and Roll-Over Valve . . 20
General Information ....................... 14
Identifying Flexible Fuel Components .......... 14
Methanol Concentration Sensor .............. 18
Pressure Vacuum Fuel Filler Tube Cap ........ 14
Service Precautions for Flexible Fuel Vehicles . . . 14
GENERAL INFORMATION
The fuel tanks of Chrysler Corporation built vehi-
cles are equipped with fuel and vapor controls that
allow the vehicle to pass a full 360É rollover. The fuel delivery system used on front wheel drive
vehicles contains a fuel tank pressure relief/rollover
valve. The valve mounts on the top of the fuel tank.
The valve functions as a pressure relief valve while
the vehicle is upright. The valve also contains a
check valve that prevents fuel from escaping the fuel
tank if the vehicle turns over. The fuel filler cap also acts as a pressure/vacuum
valve. When pressure inside the fuel tank gets too
high or too low, the fuel filler cap opens to relieve
the difference in air pressure. An evaporation control system restricts fuel evapo-
ration into the atmosphere and reduces unburned hy-
drocarbons. Vapors from the fuel tank are collected
in a charcoal filled canister. The vapors are held in
the canister until the engine is operating. When the
engine operates, vapors are drawn through the in-
take manifold into the combustion chambers.
FLEXIBLE FUEL VEHICLES
Beginning this model year, Chrysler began produc-
ing AA-Body vehicles designed to operate on a mix-
ture of gasoline and methanol. These automobiles are
referred to as Flexible Fuel Vehicles. Flexible fuel vehicles can operate on a mixture of
up to 85 percent methanol, 15 percent unleaded gas-
oline. These vehicles also operate on mixtures con-
taining a lower percentage of methanol or just pure
unleaded gasoline. In many cases, the procedures for servicing flexible
fuel components is identical to gasoline only compo-
nents. Refer to the particular Service Procedure in
this section. If the service procedure for flexible fuel
component differs from a gasoline only component,
the title of each service procedure identifies the ap-
plication.
IDENTIFYING FLEXIBLE FUEL COMPONENTS
Flexible Fuel vehicles have unique methanol com-
patible fuel system components. Chrysler identifies
methanol compatible components that could be phys-
ically interchanged with gasoline only parts by color-
ing them green or applying a green label or tag to
them. Even though they may appear physically iden-
tical, components for gasoline only AA-body vehicles
must not be used on flexible fuel vehicles.
SERVICE PRECAUTIONS FOR FLEXIBLE FUEL
VEHICLES
Methanol is more toxic than gasoline. Always re-
lease fuel system pressure before servicing fuel sys-
tem components and wear methanol resistant gloves
and eye protection. Avoid breathing methanol vapors or ingesting
methanol. Headaches, dizziness and even uncon-
sciousness could result from breathing these vapors.
Serious injury, blindness and even death could result
from ingesting methanol. Methanol vapors are extremely flammable and can
travel along the ground. Service vehicles in well ven-
tilated areas and avoid ignition sources. Never
smoke while servicing the vehicle. Do not allow methanol to contact skin. Prolonged
contact with methanol can cause dry skin or an al-
lergic skin reaction. Also, prolonged contact could re-
sult in absorption through the skin.
PRESSURE VACUUM FUEL FILLER TUBE CAP
WARNING: REMOVE FUEL FILLER TUBE CAP TO
RELIEVE TANK PRESSURE BEFORE REMOVING
OR REPAIRING FUEL SYSTEM COMPONENTS.
The loss of any fuel or vapor out of the filler tube
neck is prevented by the use of a safety filler cap.
The cap releases only under significant pressure 10.9
to 13.45 kPa (1.58 to 1.95 psi). The vacuum release
for all gas caps is between .97 and 2.0 kPa (.14 and
.29 psi). The cap must be replaced by a similar unit
in order for the system to remain effective.
14 - 14 FUEL SYSTEMS Ä

INSTALLATION
WARNING: FUEL TANKS DESIGNED FOR GASO-
LINE ONLY VEHICLES CANNOT BE USED ON
FLEXIBLE FUEL AA-BODY VEHICLES. WHEN SER-
VICING THE FUEL SYSTEM OF A FLEXIBLE FUEL
VEHICLE, ONLY USE ORIGINAL EQUIPMENT OR
EQUIVALENT REPLACEMENT COMPONENTS. (1) Position fuel tank on transmission jack. Con-
nect vapor separator/rollover valve hose and position
insulator pad on fuel tank. Position vapor vent so
that it is not pinched between tank and floor pan
during installation. (2) Raise tank and fuel filler tube carefully into
position. Use a light coating of power steering fluid
to ease fuel filler tube installation. Ensure filler tube
grommet is not damaged. Verify that the tube is in-
stalled correctly. (3) Tighten fuel tank strap nuts to 23 N Im (250 in.
lbs.) torque. Remove transmission jack. Ensure
straps are not twisted or bent. (4) Lubricate the metal tubes on the fuel pump
with clean 30 weight engine oil. Install the quick
connect fuel fittings. Refer to Quick Connect Fittings
in the Fuel Delivery section of this Group. (5) Attach electrical connector to fuel pump mod-
ule and level sensor unit. (6) Lower the vehicle.
(7) Attach filler tube to filler neck opening in
quarter panel. Tighten quarter panel screws to 2
N Im (17 in. lbs.) torque.
(8) Fill fuel tank, install filler cap, and connect
battery cable.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) Relay remains energized
for either 7 minutes, until the test is stopped, or un-
til the ignition switch is turned to the Off position.
(9) Use the DRBII scan tool ASD Fuel System Test
to pressurize the fuel system. Check for leaks.
FUEL PUMP MODULE
Refer to the Fuel Delivery section of this group.
METHANOL CONCENTRATION SENSOR
Refer to the Fuel Delivery section of this group.
FUEL RESERVOIR
The fuel reservoir is internal to the fuel pump as-
sembly (Fig. 6). The purpose is to provide fuel at the
fuel pump intake during all driving conditions, espe-
cially when low fuel levels are present.
FUEL TANK LEVEL SENSOR
DIAGNOSIS
This procedure test the resistance of the level sen-
sor itself. It does not test the level sensor circuit. Re-
fer to Group 8W, Wiring Diagrams for circuit
identification and Group 8E, Instrument Panel and
Gauges for fuel gauge information. The level sensor is a variable resistor. Its resis-
tance changes with the amount of fuel in the tank.
The float arm attached to the sensor moves as the
fuel level changes. To test the level sensor, connect
an ohmmeter across the sensor signal and sensor
ground terminals of the fuel level sensor connector
(Fig. 7 or Fig. 8). Move the float lever to the full stop
and empty stop positions shown in the resistance
chart (Fig. 7 or Fig. 8). Record the resistance at each
point. Replace the level sensor if the resistance is not
within specifications. The low fuel warning light specifications determine
if the level sensor portion of the warning light circuit
functions properly. It does not test the complete
warning light circuit. Refer to Group 8W, Wiring Diagrams for circuit
identification and Group 8E, Instrument Panel and
Gauges for fuel gauge information.
REMOVAL
WARNING: RELEASE FUEL SYSTEM PRESSURE
BEFORE SERVICING FUEL SYSTEM COMPONENTS.
WHEN SERVICING FLEXIBLE FUEL VEHICLES,
WEAR METHANOL RESISTANT GLOVES AND EYE
PROTECTION AND AVOID BREATHING FUMES. DO
NOT ALLOW METHANOL/GASOLINE MIXTURES TO
CONTACT SKIN. SERVICE VEHICLES IN WELL VEN-
TILATED AREAS AND AVOID IGNITION SOURCES.
NEVER SMOKE WHILE SERVICING THE VEHICLE.
Fig. 6 Fuel Reservoir
14 - 18 FUEL SYSTEMS Ä

The fuel tank must be removed to service the fuel
sending unit. Refer to Fuel Tank Removal in this
section. (1) Using a hammer and brass drift punch, care-
fully tap lock ring counterclockwise to release send-
ing unit (Fig. 9). (2) Lift level unit and O-ring away from tank (Fig.
10 or Fig. 11).
INSTALLATION
WARNING: FUEL LEVEL SENSORS DESIGNED FOR
GASOLINE ONLY VEHICLES CANNOT BE USED ON
FLEXIBLE FUEL AA-BODY VEHICLES. WHEN SER-
VICING THE FUEL SYSTEM OF A FLEXIBLE FUEL VEHICLE, ONLY USE ORIGINAL EQUIPMENT OR
EQUIVALENT REPLACEMENT COMPONENTS.
(1) Wipe seal area of tank clean and place a new
O-ring seal in position. (2) Place sending unit in tank. Position lock ring
in place. Using a brass drift and hammer, tap ring in
a clockwise direction. (3) Install tank.
Fig. 8 Level Sensor DiagnosisÐFlexible Fuel AA-Body
Fig. 7 Level Sensor DiagnosisÐExcept Flexible Fuel AA-Body
Ä FUEL SYSTEMS 14 - 19