fuel pressure CHEVROLET DYNASTY 1993 Service Manual

² SG service engine oil is a high quality crankcase
lubricant designed for use in all naturally aspirated
engines. If SG service engine oil is used in turbo-
charged engine, change engine oil at every 4 800
km (3,000 miles) or three months.
² SG/CD service engine oil is a high quality crank-
case lubricant designed for use in most naturally as-
pirated and turbocharged gasoline or diesel engines.
FLEXIBLE FUEL VEHICLES
Vehicles operated using Flexible Fuel (M85) re-
quire engine oil that meet or exceed Chrysler Stan-
dard MS-9214. Mopar Flexible Fuel engine oil or
equivalent should be used when adding or changing
crankcase lubricant. The API symbol (Fig. 1) on the
container indicates the viscosity grade, quality and
fuel economy ratings of the lubricant it contains. Use
ENERGY CONSERVING II motor oil with API SER-
VICE SG or SG/CD classification.
ENGINE OIL ADDITIVES
Chrysler Corporation recommends that Mopar En-
gine Oil Supplement or equivalent be used when fric-
tion and corrosion reducing materials added to the
crankcase lubricant is desired.
CRANKCASE OIL LEVEL INSPECTION
CAUTION: Do not overfill crankcase with engine oil,
oil foaming and oil pressure loss can result.
Inspect engine oil level approximately every 800
kilometers (500 miles). Position vehicle on level sur- face. With engine OFF, allow enough time for oil to
settle to bottom of crankcase, remove engine oil level
indicator (dipstick) and wipe clean. Install dipstick
and verify it is seated in the tube. Remove dipstick,
with handle above tip, take oil level reading (Fig. 2).
Add oil only if level is below MIN or ADD mark on
dipstick.
ENGINE OIL CHANGE
Change engine oil at mileage and time intervals
described in Lubrication and Maintenance Schedules.
Position the vehicle on a level surface. Hoist and
support vehicle on safety stands. Refer to Hoisting
and Jacking Recommendations in this group. Place a
suitable 3.8 liter (4 qt.) drain pan under crankcase
drain. Remove drain plug from crankcase. Inspect
drain plug threads for stretching or other damage.
Replace drain plug and gasket if damaged. Install
drain plug in crankcase. Lower vehicle and fill
crankcase with specified type and amount of engine
oil described in this section. Start engine and inspect
for leaks. Stop engine and inspect oil level.
ENGINE OIL FILTER
SELECTING OIL FILTER
Chrysler Corporation recommends a Mopar or
equivalent oil filter be used when replacement is re-
quired. A replacement filter must be designed to
withstand 1756 kPa (256 psi) of internal pressure.
OIL FILTER REPLACEMENT
Position a drain pan under the oil filter. Using a
suitable oil filter wrench (Fig. 3) loosen filter. When
filter separates from adapter nipple, tip gasket end
upward to minimize oil spill. Remove filter from ve-
hicle. With a wiping cloth, clean the gasket sealing
surface (Fig. 4) of oil and grime. Wipe off oil residue
from below oil filter adapter.
TO INSTALL NEW OIL FILTER: Lightly lubricate oil filter gasket with engine oil or
chassis grease. Thread filter onto adapter nipple.
When gasket makes contact with sealing surface,
tighten filter one full turn. If necessary use a filter
wrench, do not over tighten. Add oil, verify crank-
case oil level and start engine. Inspect for oil leaks.
RECOMMENDED VISCOSITY GRADES
Fig. 1 API Symbol
Fig. 2 Oil Level Indicator DipstickÐTypical
Ä LUBRICATION AND MAINTENANCE 0 - 9

tifreeze to achieve adequate protection. A mix table
on the coolant container indicates the amount of an-
tifreeze required to winterize the cooling system
based on the capacity, see Capacity Chart in General
Information section of this group.
SELECTING ANTIFREEZE
Chrysler Corporation recommends Mopar Anti-
freeze/Summer Coolant, or equivalent be used to win-
terize and protect cooling system.
RADIATOR CAP
The radiator cap must be secure to provide proper
pressure release and coolant recovery. Inspect and
test radiator cap when cooling system service is per-
formed or when problem is suspected.
COOLING SYSTEM SERVICE
The cooling system should be drained, flushed and
filled with the proper coolant mixture at the inter-
vals described in the Lubrication and Maintenance
Schedules. Refer to General Information section of
this group. For proper service instructions see Group
7, Cooling System.
ENGINE AIR CLEANER
The engine air cleaner should be serviced at the in-
tervals described in the Lubrication and Mainte-
nance Schedules. Refer to General Information
section of this group. Additional information can be
found in Group 14, Fuel System and Group 25, Emis-
sion System. Inspect all air cleaner hoses or tubes for
damage or leaks when other engine compartment
service is performed. Replace faulty components.
AIR CLEANER SERVICE
CAUTION: The air cleaner cover must be installed
properly for the emissions system and engine con-
troller to function correctly. Do not immerse paper air filter element or temper-
ature sensor in cleaning solvents, damage can re-
sult.
TO SERVICE AIR CLEANER ASSEMBLY: (1) Raise hood of vehicle and inspect all air cleaner
components for damage or improper attachment. (2) Remove air cleaner cover (Fig. 6, 7, 8, 9, or 10).
(3) Remove paper air filter element from air
cleaner body. Hold a shop light on throttle body side
of element. Inspect air intake side of element. If light
is visible through element, blow dust from element
(Fig. 11) and reuse. If element is saturated with oil
or light is not visible, replace filter. If element is sat-
urated with oil, perform crankcase ventilation sys-
tem tests. (4) Remove fiber crankcase filter (Fig. 6, 7, 8, 9, or
10) and clean with solvent, squeeze filter dry and ap- ply small amount of engine oil. If a metallic mesh is
used to retain fiber filter, clean mesh with solvent
and reuse.
(5) Clean inside of air cleaner cover and body with
vacuum or compressed air. If oily, wash with solvent. To Install, reverse the preceding operation.
Fig. 6 Air CleanerÐ3.0L Engine
Fig. 7 Air CleanerÐFlexible Fuel Engine
Fig. 8 Air CleanerÐ16 Valve Engine
Ä LUBRICATION AND MAINTENANCE 0 - 11

CRANKCASE VENTILATION SYSTEM
Engine crankcase pressure and emissions are
vented into combustion chambers through the posi-
tive crankcase ventilation (PCV) system. The PCV
system consists of a crankcase filter (Fig. 6, 7, 8, 9,
or 10), PCV valve (Fig. 12, 13, 14 or 15) and hoses to
complete a vacuum circuit. The PCV system should
have enough volume to overcome crankcase pressure
created by piston backwash. If a PCV system be-
comes plugged, the crankcase pressure will increase
and force engine oil past the piston rings creating oil
consumption. Blockage of PCV system can occur at
the vacuum source coupling, PCV valve, crankcase
filter or a collapsed hose. Chrysler Corporation recommends that a PCV
valve not be cleaned. A new Mopar or equivalent
PCV valve should be installed when servicing is re-
quired. Over a period of time, depending on the en-
vironment where vehicle is used, deposits build up in
the PCV vacuum circuit. PCV system should be in-
spected at every oil change. Service PCV system if
engine oil is discharged into air cleaner.
Fig. 11 Cleaning Air Filter Element
Fig. 12 PCV SystemÐ3.0L Engine
Fig. 13 PCV SystemÐFlexible Fuel Engine
Fig. 14 PCV SystemÐ3.3L or 3.8L Engine
Fig. 15 PCV SystemÐ2.2L or 2.5L EFI Engine
Ä LUBRICATION AND MAINTENANCE 0 - 13

BRAKE RESERVOIR LEVEL INSPECTION
WARNING: DO NOT ALLOW PETROLEUM OR WATER
BASE LIQUIDS TO CONTAMINATE BRAKE FLUID,
SEAL DAMAGE AND BRAKE FAILURE CAN RESULT.
RELIEVE PRESSURE IN ANTI-LOCK BRAKE SYS-
TEM BEFORE ADDING BRAKE FLUID TO RESER-
VOIR. IF NOT, BRAKE FLUID COULD DISCHARGED
FROM THE RESERVOIR POSSIBLY CAUSING PER-
SONAL INJURY.
The brake reservoir level should be inspected when
other under hood service is performed. It is normal
for the reservoir level to drop as disc brake pads
wear. When fluid must be added, use Mopar, Brake
Fluid or equivalent. Use only brake fluid conforming
to DOT 3, Federal, Department of Transportation
specification. To avoid brake fluid contamination, use
fluid from a properly sealed container. On vehicles with anti-lock brakes, depressurize the
system before inspecting fluid level. Turn OFF the
ignition and remove the key. Pump the brake pedal
at least 50 times to relieve the pressure in the sys-
tem.
On all vehicles, if fluid should become low after sev-
eral thousand kilometers (miles), fill the reservoir to
level marks on the side of the reservoir (Fig. 8 or 9).
HEADLAMPS
The headlamps should be inspected for intensity
and aim whenever a problem is suspected. When lug-
gage compartment is heavily loaded, the headlamp
aim should be adjusted to compensate for vehicle
height change. For proper service procedures, refer to
Group 8L, Lamps. DRIVER SUPPLEMENTAL AIRBAG SYSTEM
If the AIRBAG indicator lamp does not light at all,
stays lit or lights momentarily or continuously while
driving, a malfunction may have occurred. Prompt service is required. Refer to Group 8M, Restraint
Systems for proper diagnostic procedures.
BODY LUBRICATION
Body mechanisms and linkages should be inspected,
cleaned and lubricated as required to maintain ease of
operation and to prevent corrosion and wear. Before a component is lubricated, oil, grease and dirt
should be wiped off. If necessary, use solvent to clean
component to be lubricated. After lubrication is com-
plete, wipe off excess grease or oil. During winter season, external lock cylinders should
be lubricated with Mopar, Lock Lubricant or equiva-
lent to ensure proper operation when exposed to water
and ice. To assure proper hood latching component operation,
use engine oil to lubricate the lock, safety catch and
hood hinges when other under hood service is per-
formed. Mopar, Multi-purpose Grease or equivalent
should be applied sparingly to all pivot and slide
contact areas.
USE ENGINE OIL ON:
² Door hingesÐHinge pin and pivot points.
² Hood hingesÐPivot points.
² Luggage compartment lid hingesÐPivot points.
USE MOPAR LUBRIPLATE OR EQUIVALENT ON:
² Door check straps.
² Hood counterbalance springs.
² Luggage compartment lid latches.
² Luggage compartment lid prop rod pivots.
² Ash tray slides.
² Fuel Fill Door latch mechanism.
² Park brake mechanism.
² Front seat tracks.
Fig. 8 Anti-lock Brake Reservoir
Fig. 9 Master Cylinder Brake ReservoirÐExcept
Anti-lock
0 - 22 LUBRICATION AND MAINTENANCE Ä

FRONT SUSPENSION SERVICE PROCEDURES INDEX
page page
Ball Joints .............................. 13
Hub and Bearing Assembly ................. 20
Knuckle (Front Suspension) ................. 16
Lower Control Arm ....................... 10
Lower Control Arm Pivot Bushings ........... 11 Shock Absorbers (Strut Damper)
............. 10
Strut Damper Assembly ..................... 7
Suspension Coil Springs .................... 9
Sway Bar .............................. 14
Wheel Alignment .......................... 5
WHEEL ALIGNMENT
Front wheel alignment is the proper adjustment of
all interrelated front suspension angles. These angles
are what affects the running and steering of the
front wheels of the vehicle. The method of checking front alignment will vary
depending on the type of equipment being used. The
instructions furnished by the manufacturer of the
equipment should always be followed. With the ex-
ception that the alignment specifications recom-
mended by Chrysler Corporation be used. There are six basic factors which are the founda-
tion to front wheel alignment. These are height,
caster, camber, toe-in, steering axis inclination and
toe-out on turns. Of the six basic factors only camber
and toe in are mechanically adjustable (Fig. 1)
CAUTION: Do not attempt to modify any suspen-
sion or steering components by heating or bending
of the component.
Wheel alignment adjustments and checks should be
made in the following sequence. (1) Camber
(2) Toe
Camber is the number of degrees the top of the
wheel is tilted inward or outward from true vertical.
Inward tilt is negative camber. Outward tilt is posi-
tive camber. Excessive camber is a tire wear factor: negative
camber causes wear on the inside of the tire, while
positive camber causes wear to the outside. Toe
is measured in degrees or inches and is the
distance the front edges of the tires are closer (or far-
ther apart) than the rear edges. See Front Wheel
Drive Specifications for Toesettings.
PRE-ALIGNMENT
Before any attempt is made to change or correct
the wheel alignment factors. The following inspection
and necessary corrections must be made on those
parts which influence the steering of the vehicle. (1) Check and inflate tires to recommended pres-
sure. All tires should be the same size and in good
condition and have approximately the same wear.
Note type of tread wear which will aid in diagnosing,
see Wheels and Tires, Group 22. (2) Check front wheel and tire assembly for radial
runout. (3) Inspect lower ball joints and all steering link-
age for looseness. (4) Check for broken or sagged front and rear
springs. Front suspension must only be checked after the
vehicle has had the following checked or adjusted.
Tires set to recommended pressures, full tank of fuel,
no passenger or luggage compartment load and is on
a level floor or alignment rack. Just prior to each alignment reading. The vehicle
should be bounced (rear first, then front) by grasping
bumper at center and jouncing each end an equal
number of times. Always release bumpers at bottom
of down cycle.
Ä SUSPENSION AND DRIVESHAFTS 2 - 5

sends the message to the Engine Controller. The En-
gine Controller turns on the fan through the fan re-
lay. See Wiring Diagrams Manual for circuity and
diagnostics provided.Switching through the Engine Controller provides
fan control for the following conditions.
² The fan will not run during cranking until the en-
gine starts no matter what the coolant temperature
is.
² Fan will run when the air conditioning clutch is
engaged and low pressure cutout switch is closed.
² For 4 cylinder application the fan will run at ve-
hicle speeds above about 40 mph only if coolant tem-
perature reaches 110ÉC (230ÉF). It will turn off when
the temperature drops to 104ÉC (220ÉF). At speeds
below 40 mph the fan switches on at 102ÉC (215ÉF)
and off at 93ÉC (200ÉF).
² This is to help prevent steaming. The fan will run
only below 16ÉC (60ÉF) ambient. Between 38ÉC
(100ÉF) to 97ÉC (195ÉF) coolant temperature, at idle
and then only for three minutes.
RADIATOR FAN CONTROLÐAC/AY BODY V-6 ONLY
For this application, fan control is accomplished
based on coolant temperature, and on A/C head pres-
sure. These vehicles receive the variable displace-
ment compressor. The fan will go on when;
² Coolant temperature reaches 102ÉC (215ÉF) and off
at 93.4ÉC (200ÉF) regardless of vehicle speed.
² When the head pressure reaches 1516.9 kPa (220
psi) and turn off when the pressure reaches 1103 kPa
(160 psi).
TEMPERATURE GAUGE INDICATION
At idle the temperature gauge will rise slowly to
about 5/8 gauge travel. The fan will come on and the
gauge will drop to about 1/2 gauge travel, this is nor-
mal.
ELECTRIC FAN MOTOR
To check out the electric fan motor, disconnect the
fan motor wire connector and connect it with #14
gauge wires to a good 12-volt battery observing cor-
rect polarity per (Fig. 14). If the fan runs normally,
the motor is functioning properly. If not, replace fan
module using the removal and installation instruc-
tions contained in the Fan Section. If the motor is
noticeably overheated (i.e.; wire insulation melted,
motor charred) the system voltage may be too high.
Check charging system, see Group 8A, Battery/Start-
ing/Charging System Diagnostics.
ELECTRIC FAN MOTOR TEST
Equipment required
² Diagnostic Tool DRB II or equivalent
² Volt/Ohm Meter
² Wiring Diagram Manual (1) Run the engine to normal operating tempera-
ture. (2) Check wiring connector in C25, C9, and C26 for
proper engagement, see Wiring Diagram Manual (3) Using a diagnostic tool, plugged into the diag-
nostic connector rearward of the battery, check the
On-Board Diagnostics (OBD) in the Engine Control-
ler for fault codes, see Group 14, Fuel Injection for
instructions. (4) If fault code 88-12-35-55 is detected, proceed to
Step 5. (5) With the ignition switch in the run position,
test for battery voltage (single pin connector) at the
fan relay. Voltage reading OK, proceed to Step 6a.
Voltage at 0-1 volt, proceed to Step 6b. 6(a) With the ignition off, disconnect the 60-way
connector from the Engine Controller (outboard of
battery) and return the ignition to the run position.
Test for battery voltage at cavity 31 of the 60-way
connector (Fig. 15). Voltage reading OK and female
terminal is not damaged, replace the Engine Control-
ler. Voltage reading 0, repair open or short in C27
circuit. (b) With the ignition off, disconnect the 60-way
connector from the Engine Controller (outboard of
battery) and return the ignition to the run position.
Test for battery voltage at the single pin connector
at the fan relay. Voltage reading OK, replace the
Engine Controller. Voltage reading 0-1 volt, pro-
ceed to Step 7.
(7) With ignition in the run position, test for bat-
tery voltage at the wire (C27) in the 3-way connector
of the fan relay. Voltage reading OK, replace the fan
relay. Voltage reading 0, repair open or short in C27
circuit. (8) Turn ignition off, connect the 60-way connector
at the Engine Controller and test the system.
Fig. 14 Electric Fan MotorÐTypical
7 - 22 COOLING SYSTEM Ä

VISUAL MESSAGES
Following are the visual messages and the condi-
tions under which, the messages will be given:
² Keys in ignition
² Exterior lamps on
These messages will appear if the conditions are
present and the driver's door is open while the igni-
tion switch is in the OFF, LOCK, or ACC positions.
A tone will sound until the condition is corrected or
the door is closed.
² Passenger door ajar
² Driver door ajar
² Trunk ajar
² Park brake engaged
² Right rear door ajar
² Left rear door ajar
These messages will appear if a condition is de-
tected after the vehicle is in motion. When the con-
dition is corrected, a short tone will sound to
acknowledge the action. LOW OIL PRESSURE
If this message is displayed while the vehicle is at
cruising speeds, immediate attention is required. If
this message appears at idle speed, increase the idle
speed and the message should go off. If the message
remains on, immediate attention is required. ENGINE TEMP CRITICAL
This message appears when a sensor has determined
that the engine coolant is overheating. If this message
comes on and stays on, immediate action is required.
COOLANT LEVEL LOW
LOW FUEL LEVEL
LOW BRAKE FLUID
WASHER FLUID LOW
These messages will appear if a continuous warn-
ing condition is detected while the engine is running.
Inspection is required. To clear this message from
the display, after the condition is corrected, the igni-
tion switch must be turned OFF. CHECK TRANS
This message will appear if a continuous warning
condition is detected while the engine is running. Im-
mediate attention is recommended. To clear this mes-
sage from the display, after the condition has been
corrected, the ignition switch must be turned OFF. VOLTAGE IMPROPER
This message will appear if a continuous warning
condition is detected. Immediate attention is re-
quired. To clear this message from the display, after
the condition has been corrected, the ignition switch
must be turned OFF. TURN SIGNAL ON
This message will appear if the turn signal is left
on while vehicle speed is over 15 mph and the vehi-
cle has traveled over one-half mile. FASTEN SEAT BELTS An intermittent chime tone will sound for several
seconds if the seat belt is not fastened. CHK ENGINE OIL LEVEL
If this message is delivered, a check of the engine
oil dipstick is suggested. To clear this message, after
the condition is corrected, the ignition switch must
be turned OFF. HEADLAMP OUT
BRAKE LAMP OUT
TAIL LAMP OUT
These conditions are monitored only when the lamps
are on. The message will remain, even after the lamp is
replaced, until the lamp is turned on and operates.
SERVICE REMINDER
The maintenance reminder statement is programmed
to provide general information only. Refer to Group 0,
Lubrication & Maintenance for specific vehicle require-
ments.
The service reminder message is displayed at 7,500
miles or 12 months intervals, which ever comes first. MONITORED SYSTEMS OK
If there is no warning condition to report, the mes-
sage Monitored Systems OK is displayed (Fig. 2).
AUTOMATIC CALIBRATION SET PROCEDURE
The engine compartment node will continuously
and automatically recalibrate the compass under nor-
mal driving conditions. As long as the vehicle is
turning, the engine compartment node will record
new compass data. This new data will be used to
recalibrate the compass at a rate of at least once per
full (360 degree) turn of the vehicle. Automatic cali-
bration does not require operator interface.
MANUAL CALIBRATION SET PROCEDURE
Manual compass calibration has been replaced by
automatic calibration set procedure. The manual cal-
ibration set procedure is available, but no longer
serves any useful purpose.
EVIC SELF CHECK DIAGNOSTICS
Ignition switch ON, the EVIC not displaying any
message, may imply a system failure and not an
EVIC failure. Turn the ignition OFF, close all vehi-
cle doors and wait at least 60 seconds before begin-
ning test. Turn ignition switch to the ON position.
Pressing the TEMP, FUEL and INFO buttons at the
same time shall provide the visual message MOD-
ULE SELF CHECK for two seconds. Following at
two second interval there will be messages:
² E2-0 SELF CHECK
² E3-0 SELF CHECK
² END OF SELF CHECK
Showing the microcomputer is working properly.
When the self check mode and message shows:
² E2-1
² E3-2
This would show a fault exists in the EVIC's micro-
computer and the EVIC should be replaced (Fig. 3).
8C - 8 OVERHEAD CONSOLE Ä

VISUAL MESSAGES
Following are the visual messages and the condi-
tions under which, the messages will be given:
² Keys in ignition
² Exterior lamps on
These messages will appear if the conditions are
present and the driver's door is open while the igni-
tion switch is in the OFF, LOCK, or ACC positions.
A tone will sound until the condition is corrected or
the door is closed.
² Passenger door ajar
² Driver door ajar
² Trunk ajar
² Park brake engaged
² Right rear door ajar
² Left rear door ajar
These messages will appear if a condition is de-
tected after the vehicle is in motion. When the con-
dition is corrected, a short tone will sound to
acknowledge the action. LOW OIL PRESSURE
If this message is displayed while the vehicle is at
cruising speeds, immediate attention is required. If
this message appears at idle speed, increase the idle
speed and the message should go off. If the message
remains on, immediate attention is required. ENGINE TEMP CRITICAL
This message appears when a sensor has deter-
mined that the engine coolant is overheating. If this
message comes on and stays on, immediate action is
required. COOLANT LEVEL LOW
LOW FUEL LEVEL
LOW BRAKE FLUID WASHER FLUID LOW
These messages will appear if a continuous warn-
ing condition is detected while the engine is running.
Inspection is required. To clear this message from
the display, after the condition is corrected, the igni-
tion switch must be turned OFF. CHECK TRANS
This message will appear if a continuous warning
condition is detected while the engine is running. Im-
mediate attention is recommended. To clear this mes-
sage from the display, after the condition has been
corrected, the ignition switch must be turned OFF. VOLTAGE IMPROPER
This message will appear if a continuous warning
condition is detected. Immediate attention is re-
quired. To clear this message from the display, after
the condition has been corrected, the ignition switch
must be turned OFF. TURN SIGNAL ON
This message will appear if the turn signal is left
on while vehicle speed is over 15 mph and the vehi-
cle has traveled over one-half mile. FASTEN SEAT BELTS
An intermittent chime tone will sound for several
seconds if the seat belt is not fastened. CHK ENGINE OIL LEVEL
If this message is delivered, a check of the engine
oil dipstick is suggested. To clear this message, after
the condition is corrected, the ignition switch must
be turned OFF. HEADLAMP OUT
BRAKE LAMP OUT
TAIL LAMP OUT
These conditions are monitored only when the
lamps are on. The message will remain, even after
the lamp is replaced, until the lamp is turned on and
operates. SERVICE REMINDER
The maintenance reminder statement is pro-
grammed to provide general information only. Refer
to Group 0, Lubrication & Maintenance for specific
vehicle requirements. The service reminder message is displayed at 7,500
miles or 12 months intervals, which ever comes first. MONITORED SYSTEMS OK
If there is no warning condition to report, the mes-
sage Monitored Systems OK is displayed (Fig. 3).
ENGINE COMPARTMENT NODE (ECN)
The Engine Compartment Node is a microcomputer
controlled unit which, informs the Electronic Vehicle
Information Center (EVIC) via the CCD bus of:
² Outside temperature
² Compass direction
and the following warning messages:
² Low Brake Fluid
² Low Coolant Level
² Low Engine Oil Level
Fig. 3 EVIC Messages and Sensors
Ä OVERHEAD CONSOLE 8C - 15

IGNITION SYSTEMS
CONTENTS
page page
2.2L TBI, 2.5L TBI, 2.5L MPI AND 3.0L IGNITION SYSTEMSÐDIAGNOSTIC PROCEDURES
..... 11
2.2L TBI, 2.5L TBI, 2.5L MPI AND 3.0L IGNI- TION SYSTEMSÐSERVICE PROCEDURES . 14
2.2L TBI, 2.5L TBI, 2.5L MPI AND 3.0L IGNI- TION SYSTEMSÐSYSTEM OPERATION .... 1
2.2L TURBO III, 3.3L AND 3.8L IGNITION SYSTEMÐDIAGNOSTIC PROCEDURES
.... 35
2.2L TURBO III, 3.3L AND 3.8L IGNITION SYSTEMÐSYSTEM OPERATION ......... 24
2.2L TURBO III, 3.3L AND 3.8L IGNITION SYSTEMSÐSERVICE PROCEDURES ...... 39
IGNITION SWITCH ...................... 45
SPECIFICATIONS ....................... 47
GENERAL INFORMATION
Throughout this group, references are made to par-
ticular vehicles by letter designation. A chart ex-
plaining the designations appears in the Introduction
Section of this manual.
2.2L TBI, 2.5L TBI, 2.5L MPI AND 3.0L IGNITION SYSTEMSÐSYSTEM OPERATION
INDEX
page page
Auto Shutdown (ASD) Relay and Fuel Pump Relay . 8
Coolant Temperature Sensor ................. 7
Distributor Cap ........................... 1
Distributor Pick-UpÐ3.0L Engine .............. 7
Distributor Pick-UpÐPCM Input ............... 6
General Information ........................ 1 Ignition Coil
.............................. 9
Manifold Absolute Pressure (MAP) Sensor ...... 8
Powertrain Control Module (PCM) ............. 6
Rotor .................................. 2
Spark Plug Cables ........................ 2
Spark Plugs ............................. 3
GENERAL INFORMATION
This section describes the ignition systems of the
2.2L TBI, 2.5L TBI, 2.5L MPI (flexible fuel AA-body)
and 3.0L engines. The Fuel Injection sections of Group 14 explain On
Board Diagnostics. Group 0, Lubrication and Maintenance, contains
general maintenance information for ignition related
items. The Owner's Manual also contains mainte-
nance information.
DISTRIBUTOR CAP
Remove the distributor cap and inspect the inside
for flash over, cracking of carbon button, lack of
spring tension on carbon button, cracking of cap, and
burned, worn terminals (Fig. 1). Also check for bro-
ken distributor cap towers. If any of these conditions
are present the distributor cap and/or cables should
be replaced. When replacing the distributor cap, transfer cables
from the original cap to the new cap one at a time.
Ensure each cable is installed into the corresponding tower of the new cap. Fully seat the wires into the
towers. If necessary, refer to the appropriate engine
firing order diagram (Fig. 2 or Fig. 3).
Fig. 1 Distributor Cap Inspection
Ä
IGNITION SYSTEMS 8D - 1

to the thermostat housing (Fig. 20). The sensor pro-
vides an input voltage to the powertrain control mod-
ule (PCM). The sensor is a variable resistance
(thermistor) with a range of -40ÉF to 265ÉF. As cool-
ant temperature varies, the sensors resistance
changes, resulting in a different input voltage to the
PCM. The PCM contains different spark advance sched-
ules for cold and warm engine operation. The sched-
ules reduce engine emissions and improve
driveability. Because spark advance changes at dif-
ferent engine operating temperatures during warm-
up, all spark advance testing should be done with the
engine fully warmed. The PCM demands slightly richer air-fuel mixtures
and higher idle speeds until the engine reaches nor-
mal operating temperature. The coolant sensor input is also used for radiator
fan control.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
The MAP sensor reacts to absolute pressure in the
intake manifold and provides an input voltage to the
powertrain control module (PCM). As engine load
changes, manifold pressure varies. The changes in
engine load causes the MAP sensors output voltage
to change. The change in MAP sensor output voltage
results in a different input voltage to the PCM. The input voltage level supplies the PCM with in-
formation relating to ambient barometric pressure
during engine start-up (cranking) and engine load
while its operating. The PCM uses this input along
with inputs from other sensors to adjust air-fuel mix-
ture. On 2.2L TBI, 2.5L TBI and 2.5L MPI (flexible fuel
AA-body) engines, the MAP sensor is mounted to the
dash panel (Fig. 21 or Fig. 22). On 3.0L engines, the
sensor is mounted to a bracket across from the dis-
tributor (Fig. 23). The sensor is connected to the
throttle body or intake manifold with a vacuum hose
and to the PCM electrically.
AUTO SHUTDOWN (ASD) RELAY AND FUEL PUMP
RELAY
The powertrain control module (PCM) operates the
auto shutdown (ASD) relay and fuel pump relay
through one ground path. The PCM operates the re-
lays by switching the ground path on and off. Both
relays turn on and off at the same time. The ASD relay connects battery voltage to the fuel
injector and ignition coil. The fuel pump relay con-
nects battery voltage to the fuel pump and oxygen
sensor heating element. The PCM turns the ground path off when the igni-
tion switch is in the Off position. Both relays are off.
When the ignition switch is in the On or Crank po-
sition, the PCM monitors the distributor pick-up sig-
Fig. 19 Coolant Temperature SensorÐ2.2L TBI, 2.5L TBI and 2.5L MPI Engines
Fig. 20 Coolant Temperature SensorÐ3.0L Engines
Fig. 21 MAP SensorÐ2.2L and 2.5L TBI Engines
8D - 8 IGNITION SYSTEMS Ä