radiator CHEVROLET DYNASTY 1993 Repair Manual

(e) Remove jumper wires.
(f) Continue fuel system service.
(4) Remove throttle cable and transaxle kickdown
linkage (Fig. 4). (5) Remove automatic idle speed (AIS) motor and
throttle position sensor (TPS) wiring connectors from
throttle body (Fig. 5). (6) Remove vacuum hose harness from throttle body
(Fig. 5). (7) Remove PCV and Brake booster hoses from Air
Intake Plenum. (8) Remove ignition coil from intake plenum (Fig. 6).
(9) Remove wiring connectors from coolant tempera-
ture sensor (Fig. 7). (10) Remove vacuum connections from air intake
plenum vacuum connector. (11) Remove fuel hoses from fuel rail (Fig. 7).
WARNING: WRAP SHOP TOWELS AROUND HOSES
TO CATCH ANY GASOLINE SPILLAGE. (12) Remove (8) Fasteners from Air Intake Plenum
to Intake Manifold (Fig. 8). (13) Remove air intake plenum (Fig. 9).
(14) Cover intake manifold with suitable cover when
servicing. (15) Remove vacuum hoses from fuel rail and fuel
pressure regulator (Fig. 10). (16) Disconnect Fuel Injector wiring harness from
engine wiring harness (Fig. 11). (17) Remove fuel pressure regulator attaching bolts
and remove regulator from rail (Fig. 12). Be careful
not to damage the rubber injector O-rings upon
removal from the ports. (18) Remove fuel rail attaching bolts and lift fuel rail
assembly from intake manifold. (19) Separate radiator hose from thermostat hous-
ing and heater hose from heater pipe. (20) Remove (8) nut and washer assemblies and
remove intake manifold (Fig. 2).
INSPECTION
Check for:
² Damage and cracks of each section (Fig. 13).
² Clogged water passages in end cross overs.
² Check for distortion of the cylinder head mounting
surface using a straightedge and thickness gauge (Fig.
14). Refer to (Fig. 15) for Specifications.
INSTALLATION
(1) Position new intake manifold gaskets on cylinder
head and install intake (cross) manifold. (2) Install (8) nuts and washers and tighten in
several steps in order shown in (Fig. 16) to 20 N Im
(174 in. lbs.). (3) Make sure the injector holes are clean and all
plugs have been removed. (4) Lube injector O-ring with a drop of clean en-
gine oil to ease installation. (5) Put the tip of each injector into their ports.
Push the assembly into place until the injectors are
seated in the ports. (6) Install the (3) fuel rail attaching bolts and
torque to 13 N Im (115 in. lbs.).
(7) Install fuel pressure regulator onto fuel rail. In-
stall attaching bolts to intake manifold. Torque reg-
ulator nuts and bracket bolts to 10 N Im (95 in. lbs.)
(Fig. 12). (8) Install fuel supply and return tube hold-down
bolt and the vacuum crossover tube hold-down bolt
and torque to 10 N Im (95 in. lbs.).
(9) Connect fuel injector wiring harness to engine
wiring harness (Fig. 11). (10) Connect vacuum harness to fuel pressure reg-
ulator and fuel rail assembly (Fig. 10). (11) Remove covering from lower intake manifold
and clean surface. (12) Place intake manifold gaskets with beaded
sealant side up on lower manifold. Put air intake in
Fig. 3 Throttle Body Assembly 3.0L
Fig. 4 Throttle Cable Attachment
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 15

place. Install attaching fasteners (8) and tighten in
several steps in sequence shown (Fig. 17) to 13 N Im
(115 in. lbs.). (13) Connect fuel line to fuel rail (Fig. 7). Torque
hose clamps to 1 N Im (10 in. lbs.).
(14) Connect vacuum harness to air intake ple-
num. (15) Connect coolant temperature sensor electrical
connector to sensor (Fig. 7). (16) Connect PCV and brake booster supply hose
to intake plenum. (17) Connect automatic idle speed (AIS) motor and
throttle position sensor (TPS) electrical connectors
(Fig. 5). (18) Connect vacuum vapor harness to throttle
body (Fig. 5). (19) Install throttle cable and transaxle kickdown
linkage (Fig. 4). (20) Install air inlet hose assembly (Fig. 3).
(21) Install radiator to thermostat housing hose
and heater hose to heater pipe nipple. (22) Fill cooling system, see Refilling System in
Cooling, Group 7. (23) Connect negative battery cable.
(24) With the DRBII Scan Tool use ASD Fuel Sys-
tem Test to pressurize system to check for leaks.
Fig. 5 Electrical and Vacuum Connections to Throttle Body
Fig. 6 Ignition Coil Removal
Fig. 7 Coolant Temperature Sensor Electrical Connections
Fig. 8 Air Intake Plenum to Intake ManifoldAttaching Bolts
Fig. 9 Removing Air Intake Plenum
11 - 16 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

EXHAUST MANIFOLDS
REMOVAL (1) Raise vehicle and disconnect exhaust pipe from
rear (cowl side) exhaust manifold at articulated joint. (2) Disconnect Oxygen Sensor lead wire at the rear
exhaust manifold (Fig. 18). (3) Remove bolts attaching cross-over pipe to man-
ifold (Figs. 2 and 19). (4) Remove nuts attaching rear manifold to cylin-
der head and remove manifold.
(5) Lower vehicle and remove screws attaching
front heat shield to front manifold (Fig. 2). (6) Remove bolts fastening crossover pipe to front
exhaust manifold and nuts fastening manifold to cyl-
inder head. Remove assemblies.
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. 20).
INSTALLATION Install the gaskets with the numbers 1-3-5 em-
bossed on the top on the rear bank and those with
numbers 2-4-6 on the front (Radiator side) bank (Fig.
21). (1) Install rear exhaust manifold and tighten at-
taching nuts to 20 N Im (175 in. lbs.).
Fig. 15 Intake Plenum and Cylinder Head Mounting
Surface Specifications
Fig. 16 Nut Tightening Sequence for Intake (Cross) Manifold
Fig. 17 Intake Plenum Tightening Sequence
Fig. 18 Separate Articulated Joint, DisconnectOxygen Sensor Wire
Fig. 19 Crossover Pipe
11 - 18 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

(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

FRAME AND BUMPERS
CONTENTS
page page
BUMPER AND FASCIA .................... 1 FRAME................................ 9
BUMPER AND FASCIA INDEX
page page
AA-Vehicle Front Bumper ................... 1
AA-Vehicle Rear Bumper ................... 5
AC-Vehicle Front Bumper ................... 2
AC-Vehicle Rear Bumper ................... 6
AG-Vehicle Front Bumper ................... 3
AG-Vehicle Rear Bumper ................... 7
AJ-Vehicle Front Bumper and Fascia .......... 4 AJ-Vehicle Rear Bumper
.................... 7
AP-Vehicle Front Bumper ................... 4
AP-Vehicle Rear Bumper ................... 7
AY-Vehicle Front Bumper ................... 5
AY-Vehicle Rear Bumper ................... 8
Safety Precautions and Warnings ............. 1
SAFETY PRECAUTIONS AND WARNINGS
WARNING: BUMPER ENERGY ABSORBER UNITS
CONTAIN PRESSURIZE GAS. DO NOT PUNCTURE
OR HEAT ABSORBER UNIT FOR ANY REASON.
PERSONAL INJURY CAN RESULT.
DO NOT VENTURE UNDER A HOISTED VEHICLE
THAT IS NOT SUPPORTED ON SAFETY STANDS.
PERSONAL INJURY CAN RESULT.
CAUTION: To avoid damaging a bright metal or
painted finish bumper or fascia, use a padded work
surface.
AA-VEHICLE FRONT BUMPER
REMOVAL (FIG. 1)
(1) Remove socket and bulb from park and turn
lamp. (2) Disconnect horn and fog lamp connectors (if
equipped). (3) Remove push-in fasteners holding sight shield
to vertical support in front of radiator. (4) Remove nuts holding fascia to fender, from be-
hind forward flange of fender. (5) Support front bumper assembly on suitable lift-
ing device and remove bolts holding bumper rein-
forcement to energy absorber units.
INSTALLATION
Reverse the preceding operation. Align bumper
height to approximately 3 mm (1/8 in.) gap to bottom
of head lamp assemblies and flush to front fenders
below the side marker lamps.
Fig. 1 Standard Front BumperÐAA-Vehicle
Ä FRAME AND BUMPERS 13 - 1

BUMPER AND WRAP-AROUND FASCIA REMOVAL (FIG. 2)
(1) Remove socket and bulb from park and turn
lamp. (2) Disconnect horn and fog lamp connectors (if
equipped). (3) Remove push-in plastic fasteners at forward
edge of front wheel opening. (4) Remove pal-nut fasteners from behind front
fenders rearward of the side marker lamp. (5) Remove push-in, fasteners holding sight shield
to vertical support in front of radiator. (6) Remove nuts holding fascia to fender, from be-
hind forward flange of fender. (7) Support front bumper on suitable lifting device
and remove bolts holding bumper reinforcement to
energy absorber units.
INSTALLATION
Reverse the preceding operation. Align bumper
height to approximately 3 mm (1/8 in.) gap to bottom
of head lamp assemblies and flush to front fenders
below the side marker lamps.
BUMPER OVERHAUL (FIG. 3)
(1) Position bumper assembly on a suitable padded
work surface to avoid damage to painted fascia. (2) Remove sight shield push-in, fasteners and sep-
arate shield from assembly. (3) Remove air dam screws and push-in fasteners
and lift dam out of retaining channels at ends of fas-
cia. Remove dam retaining channels and reinforce-
ments from fascia (if equipped). (4) Remove park and turn signal lamp assemblies,
see Group 8L, Lamps (5) Remove fog lamp bracket from bottom of
bumper reinforcement (if equipped). (6) Remove horns from back of bumper reinforce-
ment. (7) Remove lower air intake louver screws and
push-in fastener and separate louver from fascia. (8) Remove upper reinforcement to fascia attaching
bolts and separate reinforcement from fascia. (9) Straighten toy-tab fasteners holding horizontal
moulding to fascia and separate moulding from two
sided adhesive tape behind moulding. Remove moul-
ding from fascia.
BUMPER ASSEMBLY
Reverse the preceding operation.
AC-VEHICLE FRONT BUMPER
FRONT BUMPER AND STANDARD FASCIA REMOVALÐAC/D OR AC/C-H- BODY (FIG. 4)
(1) Remove nuts holding fascia to fender, from be-
hind forward flange of fender. (2) Support front bumper assembly on suitable lift-
ing device and remove bolts holding bumper rein-
forcement to energy absorber units. (3) Separate bumper from vehicle.
INSTALLATION
Reverse the preceding operation. Align bumper
height to fit flush to bottom of head lamp assemblies
and grille.
FRONT BUMPER OVERHAULÐAC\ OR AC/C-H- BODY (FIG. 4)
(1) Position bumper assembly on a suitable padded
work surface to avoid damage to painted fascia. (2) Remove push-in fasteners holding fascia to re-
inforcement. (3) Remove upper reinforcement to fascia attaching
bolts and separate reinforcement from fascia.
Fig. 2 Wrap-around Front BumperÐAA-Vehicle
Fig. 3 Front Bumper OverhaulÐAA-Vehicle
13 - 2 FRAME AND BUMPERS Ä

FRONT BUMPER ASSEMBLY
Reverse the preceding operation.
FRONT BUMPER AND FASCIA REMOVALÐAC/ C-BODY (FIG. 5)
(1) Raise vehicle and support on safety stands.
(2) Remove push-in fasteners holding bumper fas-
cia to front wheel opening lip. (3) Support bumper on a suitable lifting device.
(4) Remove nuts holding bumper reinforcement to
energy absorbers. (5) Separate bumper from vehicle.
INSTALLATION
Reverse the preceding operation.
BUMPER OVERHAULÐAC/C-BODY
(1) Position bumper assembly on a suitable padded
work surface to avoid damage to painted fascia. (2) Remove bolts holding bumper face bar to rein-
forcement. (3) Remove push-in fasteners holding fascia to re-
inforcement. (4) Separate reinforcement from fascia.
BUMPER ASSEMBLY
Reverse the preceding operation.
AG-VEHICLE FRONT BUMPER
FRONT BUMPER FASCIA REMOVAL (FIG. 6)
(1) Remove headlamp and fog lamp (if equipped)
assemblies, refer to Group 8L, Lamps. (2) Raise vehicle and support on safety stands.
(3) Remove radiator closure panel sight shield.
(4) Remove push-in fasteners holding fascia to
front fender wheel opening flange. (5) Remove nuts holding fascia to fender from
above side marker reflectors. Remove fender splash
shields if necessary. (6) Remove nuts holding front fascia headlamp
mounting panel to forward edge of fenders. (7) Remove bolts holding fascia headlamp mount-
ing panel to radiator closure panel brace. (8) Remove push-in fasteners holding fascia to bot-
tom of bumper reinforcement. (9) Separate front bumper fascia and headlamp
mounting panel from vehicle.
INSTALLATION
Reverse the preceding operation. If headlamps re-
quire aiming, refer to Group 8L, Lamps.
HEADLAMP MOUNTING PANEL REMOVALÐAG-VEHICLE (FIG. 7)
(1) Remove all lamp assemblies, refer to group 8L,
Lamps. (2) Remove front bumper fascia.
(3) Remove bolts holding fascia to headlamp
mounting panel ends. (4) Remove push-in fasteners holding fascia to
headlamp mounting panel. (5) Separate headlamp mounting panel from fascia.
INSTALLATION
Reverse the preceding operation
Fig. 4 Front BumperÐAC\ or AC/C-H-Body
Fig. 5 Front BumperÐAC/C-Body
Fig. 6 Front Bumper FasciaÐAG-Vehicle
Ä FRAME AND BUMPERS 13 - 3

2.2L/2.5L SINGLE POINT FUEL INJECTIONÐSYSTEM OPERATION INDEX
page page
Air Conditioning (A/C) Clutch RelayÐPCM Output.28
Air Conditioning Switch SenseÐPCM Input ..... 26
Auto Shutdown (ASD) Relay and Fuel Pump RelayÐPCM Output ..................... 29
Battery VoltageÐPCM Input ................ 26
Brake SwitchÐPCM Input .................. 26
EVAP Canister Purge SolenoidÐPCM Output . . . 29
CCD Bus .............................. 25
Coolant Temperature SensorÐPCM Input ...... 26
Data Link ConnectorÐPCM Output ........... 30
Distributor (Hall Effect) Pick-UpÐPCM Input .... 26
Electric Electronic Gas RecirculationÐPCM Output.30
Fuel InjectorÐPCM Output ................. 31
Fuel Pressure Regulator ................... 33
General Information ....................... 24
Generator FieldÐPCM Output ............... 31
Heated Oxygen Sensor (O
2Sensor)ÐPCM Input . 27
Idle Air Control MotorÐPCM Output .......... 29 Ignition CoilÐPCM Output
.................. 31
Malfunction Indicator Lamp (Check Engine)ÐPCM Output ............................... 30
Manifold Absolute Pressure (MAP) SensorÐPCM Input ................................ 27
Modes of Operation ....................... 32
Part Throttle Unlock SolenoidÐPCM Output .... 31
Powertrain Control Module ................. 25
Radiator Fan RelayÐPCM Output ............ 31
Speed Control SolenoidsÐPCM Output ........ 31
Speed ControlÐPCM Input ................. 27
System Diagnosis ........................ 25
TachometerÐPCM Output .................. 32
Throttle Body ............................ 33
Throttle Position Sensor (TPS)ÐPCM Input ..... 28
Transaxle Park/Neutral SwitchÐPCM Input ..... 28
Vehicle Speed SensorÐPCM Input ........... 28
GENERAL INFORMATION
The computer regulated, Electronic Fuel Injection
System (Fig. 1) provides a precise air/fuel ratio for
all driving conditions. The fuel injection system is
controlled by the powertrain control module (PCM).
The PCM is a pre-programmed digital computer. The
PCM regulates ignition timing, air-fuel ratio, emission
control devices, cooling fan, charging system, speed con-
trol, and idle speed. The PCM can adapt its requirement
to meet changing operating conditions.
Fig. 1 Electronic Fuel Injection Components
14 - 24 FUEL SYSTEMS Ä

Various sensors provide the inputs necessary for
the PCM to correctly regulate fuel flow at the fuel
injector. These include the manifold absolute pres-
sure, throttle position, oxygen sensor, coolant tem-
perature, and vehicle speed sensors. In addition to
the sensors, various switches and relays provide im-
portant information and system control. The inputs
include the park/neutral switch and air conditioning
clutch switch. The outputs include the auto shutdown
relay and fuel pump relay. All inputs to the PCM are converted into signals.
Based on these inputs the PCM adjusts air-fuel ratio,
ignition timing and other controlled outputs. The
PCM adjusts the air-fuel ratio by changing the injec-
tor pulse width. Injector pulse width is the period of
time the injector is energized.
SYSTEM DIAGNOSIS
The PCM tests many of its own input and output
circuits. If a fault is found in a major system, the in-
formation is stored in memory. Technicians can dis-
play fault information through the instrument panel
Malfunction Indicator lamp (instrument panel Check
Engine lamp) or by connecting the DRBII scan tool.
For diagnostic trouble code information, refer to On
Board Diagnostics in 2.2L/2.5L Single Point Fuel In-
jectionÐGeneral Diagnosis section of this group.
CCD BUS
Various modules exchange information through a
communications port called the CCD Bus. The pow-
ertrain control module (PCM) transmits vehicle load
data on the CCD Bus.
POWERTRAIN CONTROL MODULE
The powertrain control module (PCM) is a digital
computer containing a microprocessor (Fig. 2). The
PCM receives input signals from various switches
and sensors that are referred to as PCM Inputs.
Based on these inputs, the PCM adjusts various en-
gine and vehicle operations through devices that are
referred to as PCM Outputs. PCM Inputs:
² Air Conditioning Controls
² Battery Voltage
² Brake Switch
² Coolant Temperature Sensor
² Distributor (Hall Effect) Pick-up
² Manifold Absolute Pressure (MAP) Sensor
² Oxygen Sensor
² SCI Receive
² Speed Control System Controls
² Throttle Position Sensor
² Park/Neutral Switch (automatic transaxle)
² Vehicle Speed Sensor
PCM Outputs:
² Air Conditioning Clutch Relay
² Generator Field ²
Idle Air Control Motor
² Auto Shutdown (ASD) Relay
² Canister Purge Solenoid
² Malfunction Indicator (Check Engine) Lamp
² Data Link Connector (Diagnostic Connector)
² Electronic EGR Transducer
² Fuel Injector
² Ignition Coil
² Part Throttle Unlock Solenoid (Automatic Tran-
saxle)
² Radiator Fan Relay
² Speed Control Solenoids
² Tachometer Output
Based on inputs it receives, the PCM adjusts fuel
injector pulse width, idle speed, ignition spark ad-
vance, ignition coil dwell and canister purge opera-
tion. The PCM regulates operation of the EGR,
cooling fan, A/C and speed control systems. The PCM
changes generator charge rate by adjusting the gen-
erator field. The PCM adjusts injector pulse width (air-fuel ra-
tio) based on the following inputs.
² battery voltage
² coolant temperature
² exhaust gas content
² engine speed (distributor pick-up)
² manifold absolute pressure
² throttle position
The PCM adjusts ignition timing based on the fol-
lowing inputs.
² coolant temperature
² engine speed (distributor pick-up)
² manifold absolute pressure
² throttle position
The Auto Shutdown (ASD) and Fuel Pump relays
are mounted externally, but turned on and off by the
PCM through the same circuit. The distributor pick-up signal is sent to the PCM.
If the PCM does not receive a distributor signal
within approximately one second of engine cranking,
Fig. 2 PCM
Ä FUEL SYSTEMS 14 - 25

TRANSAXLE PARK/NEUTRAL SWITCHÐPCM
INPUT
The park/neutral switch is located on the auto-
matic transaxle housing (Fig. 7). Manual transaxles
do not use park neutral switches. The switch pro-
vides an input to the PCM. The input indicates
whether the automatic transaxle is in Park, Neutral,
or a drive gear selection. This input is used to deter-
mine idle speed (varying with gear selection), fuel in-
jector pulse width, and ignition timing advance. The
park neutral switch is sometimes referred to as the
neutral safety switch.
THROTTLE POSITION SENSOR (TPS)ÐPCM INPUT
The Throttle Position Sensor (TPS) is mounted on
the throttle body and connected to the throttle blade
shaft (Fig. 8). The TPS is a variable resistor. The
sensor provides an input signal (voltage) to the PCM
representing throttle blade position. As the position
of the throttle blade changes, the resistance of the
TPS changes.
The PCM supplies approximately 5 volts to the
TPS. The TPS output voltage (input signal to the
PCM) represents the throttle blade position. The
PCM receives an input signal voltage from the TPS
varying in an approximate range of from 1 volt at
minimum throttle opening (idle) to 4 volts at wide open throttle. Along with inputs from other sensors,
the PCM uses the TPS input to determine current
engine operating conditions. The PCM adjusts fuel
injector pulse width and ignition timing based on
these inputs.
VEHICLE SPEED SENSORÐPCM INPUT
The vehicle speed sensor is located in the transaxle
extension housing (Fig. 9). The sensor input is used
by the PCM to determine vehicle speed and distance
traveled.
The speed sensor generates 8 pulses per sensor rev-
olution. These signals, along with a closed throttle
signal from the TPS, determine if a closed throttle
deceleration or normal idle condition (vehicle
stopped) exists. Under deceleration conditions, the
PCM adjusts the idle air control motor to maintain a
desired MAP value. Under idle conditions, the PCM
adjusts the idle air control motor to maintain a de-
sired engine speed.
AIR CONDITIONING (A/C) CLUTCH RELAYÐPCM
OUTPUT
The PCM operates the air conditioning clutch relay
ground circuit. The radiator fan relay supplies bat-
tery power to the solenoid side of the A/C clutch re-
lay. The air conditioning clutch relay will not
energize unless the radiator fan relay energizes. The
PCM energizes the radiator fan relay when the air
conditioning or defrost switch is put in the ON posi-
tion and the low pressure and high pressure switches
close. With the engine operating, the PCM cycles the air
conditioning clutch on and off when the A/C switch
closes with the blower motor switch in the on posi-
tion. When the PCM senses low idle speeds or wide
open throttle through the throttle position sensor, it
de-energizes the A/C clutch relay. The relay contacts
open, preventing air conditioning clutch engagement.
Fig. 7 Park/Neutral Switch
Fig. 8 Throttle Position Sensor
Fig. 9 Vehicle Distance (Speed) SensorÐTypical
14 - 28 FUEL SYSTEMS Ä