1993 CHEVROLET DYNASTY maintenance

switch connector and motor assembly. If wiring
checks good replace motor assembly.(4) To check the rear motor, connect a jumper wire
between cavity number 3 and cavity number 4. Con-
nect a second jumper wire between cavity number 6
and cavity number 13. If the motor does not operate,
reverse the jumpers, 3 to 13 and 6 to 4. If the motor
still does not operate check the wiring between
switch connector and motor assembly. If wiring
checks good replace motor assembly. (5) If all motors and the seat operate properly, per-
form Switch Test.
SWITCH TEST
To check the switch, remove the switch from its
mounting position. Using an ohmmeter, perform
switch continuity test (Fig. 5, 6 and 7). If there is no
continuity at any one of the switch positions, replace
the switch.
SEAT ASSEMBLY
REMOVAL
(1) Remove plastic covers.
(2) Remove adjuster attaching bolts and nuts from
floor pan. Move adjuster as required for access. (3) Disconnect battery negative cable.
(4) Disconnect wiring harness power lead at car-
pet. (5) Remove seat assembly from vehicle.
INSTALLATION
(1) Position seat assembly in vehicle.
(2) Connect wiring harness.
(3) Install and tighten mounting bolts and nuts to
28 N Im (250 in. lbs.) torque.
(4) Connect battery negative cable and check seat
operation. (5) Install plastic covers.
HORIZONTAL AND VERTICAL TRANSMISSIONS
Transmissions are not removable and no mainte-
nance is required. If transmission fails replace entire
seat adjuster assembly.
ADJUSTER
REMOVAL
(1) Remove seat assembly from vehicle following
procedure outlined under Seat Assembly Removal. (2) Lay seat on its back on some clean surface.
(3) Remove bolts attaching adjuster to seat assem-
bly (Fig. 8 Through 11). (4) Disconnect wiring harness at switch if seat
mounted switch is used. (5) Remove tie straps holding cable housing to seat
for power bench seat adjuster only.
INSTALLATION
(1) Lay seat on its back on a clean surface.
(2) Position adjuster to seat assembly and install
attaching bolts. (3) Connect wiring harness at switch and replace
tie straps where removed. (4) Install seat following procedure outlined under
Seat Assembly Installation.
MOTOR
REMOVAL
Anytime the motor, cable and housing assemblies,
or vertical and horizontal transmission assemblies,
require maintenance, the assemblies must be syn-
chronized to insure easy and proper operation. (1) Remove seat assembly from vehicle following
procedure outlined under Seat Assembly Removal
(Fig. 8 through 11). (2) Lay seat assembly on its back on a clean sur-
face.
Fig. 3 Left Power Seat SwitchÐAC & AY Bodies
Fig. 4 Right Power Seat SwitchÐAC & AY Bodies
Ä POWER SEATS 8R - 3

The MOPAR Silicone Rubber Adhesive Sealant
gasket material or equivalent should be applied in a
continuous bead approximately 3mm (0.120 inch) in
diameter. All mounting holes must be circled. For
corner sealing, a 3.17 or 6.35 mm (1/8 or 1/4 inch.)
drop is placed in the center of the gasket contact
area. Uncured sealant may be removed with a shop
towels. Components should be torqued in place while
the sealant is still wet to the touch (within 10 min-
utes). The usage of a locating dowel is recommended
during assembly to prevent smearing of material off
location.
CRANKSHAFT SPROCKET BOLT ACCESS PLUG
An Access plug is located in the right inner fender
shield. Remove the plug and insert proper size
socket, extension and rachet, when crankshaft rota-
tion is necessary.
ENGINE PERFORMANCE
If a loss of performance is noticed, ignition timing
should be checked. If ignition timing is retarded by
9, 18 or 27É indicating 1, 2 or 3 (timing belt or chain)
teeth may have skipped, then, camshaft and acces-
sory shaft timing with the crankshaft should be
checked. Refer to Engine Timing Sprockets and Oil
Seals of the Engine Section. To provide best vehicle performance and lowest ve-
hicle emissions, it is most important that the tune-up
be done accurately. Use the specifications listed on
the Vehicle Emission Control Information label
found in the engine compartment. (1) Test cranking amperage draw. See Starting
Motor Cranking Amperage Draw Electrical Section
of this manual. (2) Tighten the intake manifold bolts to specifica-
tions. (3) Perform cylinder compression test.(a) Check engine oil level and add oil if neces-
sary. (b) Drive the vehicle until engine reaches normal
operating temperature. (c) Select a route free from traffic and other
forms of congestion, observe all traffic laws, and ac-
celerate through the gears several times briskly.
CAUTION: Do not overspeed the engine. The higher
engine speed may help clean out valve seat deposits
which can prevent accurate compression readings.
(d) Remove all spark plugs from engine. As
spark plugs are being removed, check electrodes for
abnormal firing indicators fouled, hot, oily, etc.
Record cylinder number of spark plug for future
reference. (e) Disconnect coil wire from distributor and se-
cure to good ground to prevent a spark from start- ing a fire (Conventional Ignition System). For Direct
Ignition System DIS disconnect the coil connector. (f) Be sure throttle blade is fully open during the
compression check. (g) Insert compression gage adaptor into the #1
spark plug hole in cylinder head. Crank engine until
maximum pressure is reached on gage. Record this
pressure as #1 cylinder pressure. (h) Repeat Step G for all remaining cylinders.
(i) Compression should not be less than (689kPa)
100 psi and not vary more than 25 percent from
cylinder to cylinder. (j) If one or more cylinders have abnormally low
compression pressures, repeat steps 3b through 3h. (k) If the same cylinder or cylinders repeat an
abnormally low reading on the second compression
test, it could indicate the existence of a problem in
the cylinder in question.
The recommended compression pressures are
to be used only as a guide to diagnosing engine
problems. An engine should not be disassembled
to determine the cause of low compression un-
less some malfunction is present. (4) Clean or replace spark plugs as necessary and
adjust gap as specified in Electrical Group 8. Tighten to
specifications. (5) Test resistance of spark plug cables. Refer to
Ignition System Secondary Circuit Inspection Electri-
cal Section Group 8. (6) Inspect the primary wire. Test coil output volt-
age, primary and secondary resistance. Replace parts
as necessary. Refer to Ignition System and make nec-
essary adjustment. (7) Ignition timing should be set to specifications.
(See Specification Label in engine compartment). (8) Test fuel pump for pressure and vacuum. Refer to
Fuel System Group 14, Specifications. (9) The air filter elements should be replaced as
specified in Lubrication and Maintenance, Group 0. (10) Inspect crankcase ventilation system as out
lined in Lubrication and Maintenance, Group 0. For
emission controls see Emission Controls Group 25 for
service procedures. (11) Inspect and adjust accessory belt drives refer-
ring to Accessory Belt Drive in Cooling System, Group
7 for proper adjustments. (12) Road test vehicle as a final test.
HONING CYLINDER BORES
Before honing, stuff plenty of clean shop towels
under the bores, over the crankshaft to keep abrasive
materials from entering crankcase area. (1) Used carefully, the cylinder bore resizing hone
C-823 equipped with 220 grit stones, is the best tool for
this job. In addition to deglazing, it will reduce taper
and out-of-round as well as removing light
9 - 2 ENGINE Ä

shaft end play. A sintered iron (TBI engine and steel
billet Turbo III engines) timing belt sprocket is
mounted on the cam nose, and a hydrodynamic oil
seal is used for oil control at the front of the cam-
shaft. ACCESSORY SHAFT: The iron accessory shaft
has two bearing journals and is housed in the for-
ward facing side of the block. A hydrodynamic seal,
installed in an aluminum housing attached to the
block, provides retention, shaft thrust, and oil con-
trol. The accessory shaft is driven by the timing belt
through a sintered iron (TBI engine and steel billet
Turbo III engines) sprocket mounted on the nose of
the accessory shaft. The accessory shaft in turn
drives the oil pump and distributor on 2.2/2.5L and
2.5L FFV and the oil pump only on Turbo III. VALVES: The valves are actuated by roller cam
followers which pivot on stationary hydraulic lash
adjusters. The valve train with 40.6 mm (1.60 inch)
diameter intake valves and 35.4 mm (1.39 inch) di-
ameter exhaust valves employ viton rubber valve
stem seals except 2.5L FFv . the 2.5L FFV valve
stem seals are made of special rubber compound
which resist the deteriorating effects of methanol
fuel by-products that enter the oil during combus-
tion. Valve springs, spring retainers, and locks are
conventional. For Turbo III engines the valves are
actuated by roller tipped rocker arms with hydraulic
lash adjusters which pivot on a shaft. The valve train
with 33.88 mm (1.33 in.) diameter intake valves are
arranged in line opposite of the 29.26 mm (1.15 in.)
diameter exhaust valves employ locking valve stem
seals. Valve springs, spring retainers, and locks are
not interchangeable with other engines. BALANCE SHAFTS: 2.2 Turbo III and 2.5L en-
gines are equipped with two counter rotating balance
shafts installed in a carrier attached to the lower
crankcase. The shafts are interconnect through
gears. These gears are driven by a short chain from
the crankshaft, to rotate at two times crankshaft
speed. This counterbalances certain engine recipro-
cating forces. INTAKE MANIFOLDS:
All intake manifolds are
aluminum castings, attached to the cylinder head
with eight bolts. N.A. engines use a four branch de-
sign. This long branch fan design enhances low and
midspeed torque. It also features an integrally cast
water crossover passage to warm incoming fuel/air
mixture, plus an EGR mounting boss and PCV inlet. The Turbo III engine intake manifold is a log type
with tuned runners. The manifold is machined to ac-
cept fuel injectors near the ports of each cylinder. EXHAUST MANIFOLDS: The exhaust manifolds
are made of nodular cast iron for strength and high
temperatures. All naturally aspirated (N.A.) and tur-
bocharged engines exit exhaust gasses through a ma-
chined, articulated joint connection to the exhaust
pipe. 2.2/2.5L and 2.5L FFV manifolds intermesh
with the intake manifold at the cylinder head. N.A. engines use a four branch design with cylin-
ders one and four joined and cylinder two and three
joined to exit at the outlet. The Turbo III engine exhaust manifold also carries
the turbocharger. This manifold has a modified log
type collector with exhaust gasses directed to and
through the turbocharger to exit the conical (articu-
lated joint) outlet machined into the turbocharger ex-
haust elbow. ENGINE LUBRICATION: Refer to Group 0 Lu-
brication and Maintenance for recommended oil to be
used in various engine application. System is full
flow filtration, pressure feed type. The oil pump is
mounted within the crankcase and driven by the ac-
cessory shaft. Pressurized oil is then routed through
the main oil gallery, running the length of the cylin-
der block, supplying main and rod bearings with fur-
ther routing (for 2.2L turbo III and 2.5L engines) to
the lower balance shaft assemblies. Pistons are lubri-
cated from directed holes in the connecting rod as-
semblies. Camshaft and valve mechanisms are
lubricated from a full-length cylinder head oil gallery
supplied from the crankcase main oil gallery.
9 - 10 2.2/2.5L ENGINE Ä

EXHAUST SYSTEM AND INTAKE MANIFOLD
CONTENTS
page page
GENERAL INFORMATION .................. 1
SERVICE PROCEDURES ................... 4 TORQUE SPECIFICATION
................. 25
GENERAL INFORMATION
Throughout this group, references may be made to
a particular vehicle by letter or number designation.
A chart showing the breakdown of these designations
is included in the Introduction Section at the front of
this service manual.
EXHAUST SYSTEMS
The exhaust systems are produced in several con-
figurations, depending on engine and car line (Fig.
1). One system has an underfloor catalytic converter,
other systems require front mounted catalytic con-
verters. The Turbo III engine requires, a underfloor
converter/resonator assembly. Tail pipes, mufflers,
and resonators are sized and tuned to each vehicle/
powertrain combination (Fig. 2).
EXHAUST BALL JOINT COUPLING
A exhaust ball joint coupling (Fig. 3) is used to se-
cure the exhaust pipe to the engine manifold. This
living joint actually moves back and forth as the en- gine moves, preventing breakage that could occur
from the back-and-forth motion of a transverse
mounted engine. The exhaust ball joint consists of two bolts, two
springs, and a ball joint seal ring which is a separate
part from the exhaust pipe.
CATALYTIC CONVERTER
There is no regularly scheduled maintenance on
any Chrysler catalytic converter. If damaged, the
converter must be replaced.
CAUTION: Due to exterior physical similarities of some
catalytic converters with pipe assemblies, extreme
care should be taken with replacement parts. There is
internal converter differences required in some parts
of the country (particularly California vehicles). The
2.2/2.5L engines equipped with a manual transmission will
have an adaptor for a air injection tube.
Fig. 1 Exhaust System
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 1

CROSSMEMBER
REMOVAL (FIG. 12)
(1) Hoist vehicle and support on safety stands. Re-
fer to Group 0, Lubrication and Maintenance for
proper procedures. (2) Remove front wheels.
(3) Disconnect lower ball joints from the knuckle
assembly. Refer to Group 2, Suspension for proper
procedures. (4) Disconnect power steering hose tie-down from
rear upper edge of crossmember, if equipped. (5) Remove bolts holding steering gear to cross-
member. Refer to Group 19, Steering for proper pro-
cedures. (6) Remove bolt holding engine damper strut to crossmember, if equipped with manual transaxle.
(7) Support crossmember on a suitable lifting de-
vice. (8) Remove nuts holding rear of crossmember to
the frame. (9) Remove bolts holding crossmember to frame
from above lower control arms. (10) Separate the crossmember from the vehicle.
(11) Transfer lower control arms and sway elimi-
nator shaft to new crossmember, if crossmember is
being replaced. Refer to Group 2, Suspension for
proper procedure.
CROSSMEMBER INSTALLATION
Reverse the preceding operation.
Fig. 12 Crossmember
Ä FRAME AND BUMPERS 13 - 17

BODY DIAGNOSTIC PROCEDURES INDEX
page page
Water Leaks ............................. 2 Wind Noise.............................. 3
WATER LEAKS
Water leaks can be caused by poor sealing, improper
body component alignment, body seam porosity, miss-
ing plugs, or blocked drain holes. Centrifugal and
gravitational force can cause water to drip from an
area somewhat distant from the actual leak point,
making leak detection difficult. All body sealing points
should be water tight in normal wet driving conditions.
Water flowing downward from the front of the vehicle
should not enter the passenger or luggage compart-
ment. Moving sealing surfaces will not always seal
water tight under all conditions. At times, side glass,
door, or convertible top seals will allow water to enter
the passenger compartment during high pressure
washing or hard driving rain (severe) conditions. Over
compensating on door, glass, or top adjustments to stop
a water leak that occurs under severe conditions, can
cause premature seal wear and excessive closing or
latching effort. After a repair procedure has been
performed, water test vehicle to verify leak has stopped
before returning vehicle to use.
VISUAL INSPECTION BEFORE WATER LEAK TESTS
Verify that floor and body plugs are in place, body
drains are clear and body components are aligned and
sealed. If component alignment or sealing is necessary,
refer to the appropriate section of this group for proper
procedures.
WATER LEAK TESTS
WARNING: DO NOT USE ELECTRIC SHOP LIGHTS
OR TOOLS IN WATER TEST AREA, PERSONAL IN-
JURY CAN RESULT.
When a determination has been made on the condi-
tions that a water leak occurs, simulate the conditions
as closely as possible.
² If a leak occurs when the car is parked in a steady
light rain, flood the leak area with a open ended garden
hose.
² If a leak occurs at highway speeds in a steady rain,
test the leak area with a stream or fan spray of water
from a garden hose with an adjustable nozzle. Direct
the spray in the direction comparable to actual condi-
tions. ²
If a leak seems to occur only when the vehicle is
parked on an incline, hoist the end or side of the vehicle
to simulate this condition before water testing. This
method can also be used when the leak occurs when the
vehicle accelerates, stops, or turns. If the leak occurs
on acceleration, hoist the front of the vehicle. If the
leak occurs when braking, hoist the back of the vehicle.
If the leak occurs on left turns, hoist the left side of the
vehicle. If the leak occurs on right turns, hoist the right
side of the vehicle. For hoisting recommendations refer
to Group 0, Lubrication and Maintenance, General
Information section.
WATER LEAK DETECTION
To detect a water leak point of entry, perform a water
test and watch for water tracks or droplets forming on
the inside if the vehicle. If necessary remove interior
trim covers or panels to gain visual access to the leak
area. If the hose can not be positioned without being
held, have someone help perform the water test. Some water leaks must be tested for a considerable
length of time to become apparent. When a leak ap-
pears, determine the highest point of the water track or
drop. The highest point usually will indicate the point
of entry. After leak point has been determined, repair
the leak and water test to verify that leak has stopped. Locating the entry point of water that is leaking into
a cavity between panels can be difficult. The trapped
water splashes or runs from the cavity it is dammed up
in, often at a distance from the entry point. Most water
leaks of this type become apparent after accelerating,
stopping, turning, or when on a incline.
MIRROR INSPECTION METHOD
When a leak point area is visually obstructed, use a
suitable mirror to gain visual access. A mirror can also
be used to deflect light to a limited access area to assist
in locating a leak point.
BRIGHT LIGHT LEAK TEST METHOD
Some water leaks in the luggage compartment can be
detected without water testing. Position the vehicle in
a brightly light area. From inside the darkened lug-
gage compartment inspect around seals and body
seams. If necessary, have a helper direct a drop light
over the suspected leak areas around the lug-
23 - 2 BODY Ä

EVAPORATION CONTROL SYSTEM
The evaporation control system prevents the emis-
sion of fuel tank vapors into the atmosphere. When fuel
evaporates in the fuel tank, the vapors pass through
vent hoses or tubes to a charcoal canister. The canister
temporarily holds the vapors. The powertrain control
module (PCM) allows intake manifold vacuum to draw
vapors into the combustion chambers during certain
operating conditions. The PCM uses the canister purge
solenoid to regulate vapor flow. On 2.2L and 2.5L TBI, 3.3L, and 3.8L engines,
manifold vacuum purges the vapors at idle as well as
off idle. These engines use a bi-level purge system. The
system uses 2 sources of vacuum remove fuel vapors
from the canister. Turbo III engines use a tri-level canister purge sys-
tem. In this system, fuel vapors are drawn into the
engine through the throttle body and air cleaner. Fuel
vapors are drawn in at closed throttle, part throttle,
and wide open throttle (in boost). The 2.5L MPI (flexible fuel AA-Body) and 3.0L have
a duty cycle purge system. The powertrain control
module PCM controls vapor flow by operating the duty
cycle EVAP purge solenoid. Refer to Duty Cycle EVAP
Purge Solenoid in this section. The evaporative system uses specially manu-
factured hoses. If they need replacement, only
use fuel resistant hose.
PRESSURE RELIEF/ROLLOVER VALVE
All vehicles have a combination pressure relief and
rollover valve. The dual function valve relieves fuel
tank pressure. The valve also prevents fuel flow
through the fuel tank vent valve hoses if the vehicle
accidentally rolls over. All vehicles pass a 360É rollover. The pressure relief valve opens at a certain pressure.
When fuel tank pressure increases above the cali-
brated pressure, the valve opens to release fuel tank
vapors pressure. The evaporative (charcoal) canister
stores the vapors. For pressure relief/rollover valve
service, refer to the Fuel Tank section of Group 14.
EVAPORATIVE CANISTER
All vehicles use a sealed, maintenance free, evapora-
tive (charcoal) canister. The canister mounts to the
inner wheel well area of the engine compartment (Fig.
4 or Fig. 5). Fuel tank pressure vents into the canister. The
canister temporarily holds the fuel vapors until intake
manifold vacuum draws them into the combustion
chamber. The canister purge solenoid purges vapors
from the canister at predetermined intervals and en-
gine conditions.
CANISTER PURGE SOLENOIDÐEXCEPT 3.0L AND
2.5L MPI
The powertrain control module (PCM) operates the
canister purge solenoid (Fig. 6). During warm-up and
for a specified period after hot starts, the PCM
grounds the purge solenoid causing it to energize.
When the PCM grounds the solenoid, vacuum does
not reach the charcoal canister valve. When the engine reaches a specified operating tem-
perature and the time delay interval has occurred,
the PCM de-energizes the solenoid by turning off the
ground. When the PCM de-energizes the solenoid,
vacuum flows to the canister purge valve. Intake
manifold vacuum purges fuel vapors through the
throttle body. The PCM also energizes the purge so-
lenoid during certain idle conditions to update the
fuel delivery calibration.
DUTY CYCLE EVAP PURGE SOLENOID
Vehicles equipped with a 3.0L engine and the Flex-
ible Fuel AA-Body with the 2.5L MPI engine use a
duty cycle EVAP purge solenoid. The duty cycle
EVAP purge solenoid regulates the rate of vapor flow
from the EVAP canister to the throttle body. The
powertrain control module operates the solenoid.
Fig. 4 Evaporative CanisterÐExcept 3.0L and 2.5L MPI
Fig. 5 Evaporative CanisterÐ3.0L and 2.5L MPI
Ä EMISSION CONTROL SYSTEMS 25 - 13

TORQUE REFERENCES
Individual Torque Charts appear at the end of many
Groups. Refer to the Standard Torque Specifications
and Bolt Identification Chart in this Group for torques
not listed in the individual torque charts (Fig. 4).
Torque specifications on the Bolt Torque chart are
based on the use of clean and dry threads. Reduce the
torque by 10% when the threads are lubricated with
engine oil and by 20% if new plated bolts are used. Various sizes of Torx head fasteners are used to
secure numerous components to assemblies. Due
to ever changing usage of fasteners, Torx head
fasteners may not be identified in art or text .
METRIC THREAD AND GRADE IDENTIFICATION
Metric and SAE thread notations differ slightly. The
difference is illustrated in Figure 5. Common metric fastener strength classes are 9.8
and 12.9 with the class identification embossed on
the head of each bolt (Fig. 6). Some metric nuts will
be marked with a single digit strength number on
the nut face.
SAE strength classes range from grade 2 to 8 with
line identification embossed on each bolt head. Mark-
ings corresponding to two lines less than the actual
grade (Fig. 7). For Example: Grade 7 bolt will exhibit
5 embossed lines on the bolt head.
METRIC SYSTEM
Figure art, specifications, and tightening references
in this Service Manual are identified in the metric
system and in the SAE system. During any maintenance or repair procedures, it is
important to salvage metric fasteners (nuts, bolts,
etc.) for reassembly. If the fastener is not salvage-
able, a fastener of equivalent specification should be
used.
Fig. 6 Metric Bolt Identification
Fig. 7 SAE Bolt Identification
Fig. 4 Grade 5 and 8 Standard Torque Specifica- tions
Fig. 5 Thread Notation (Metric and SAE)
6 INTRODUCTION Ä