service schedule CHEVROLET DYNASTY 1993 User Guide

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

The camshaft position sensor senses when a notch in
the camshaft gear passes beneath it (Fig. 4). When
metal aligns with the sensor, voltage goes low (less
than 0.3 volts). When a notch aligns with the sensor,
voltage spikes high (5.0 volts). As a group of notches
pass under the sensor, the voltage switches from low
(metal) to high (notch) then back to low. The number of
notches determine the amount of pulses. If available,
an oscilloscope can display the square wave patterns of
each timing events. Top dead center (TDC) does not occur when notches
on the camshaft sprocket pass below the cylinder. TDC
occurs after the camshaft pulse (or pulses) and after
the 4 crankshaft pulses associated with the particular
cylinder.
The camshaft position sensor is mounted on the top
of the cylinder head (Fig. 5). The bottom of the sensor
is positioned above the camshaft sprocket. The dis-
tance between the bottom of sensor and the
camshaft sprocket is critical to the operation of
the system. When servicing the camshaft posi-
tion sensor, refer to the 2.2L Turbo III Multi-Port
Fuel InjectionÐService Procedures section in
this Group.
CHARGE AIR TEMPERATURE SENSORÐPCM IN-
PUT
The charge air temperature sensor is mounted to
intake manifold. The sensor measures the temperature
of the air-fuel mixture (Fig. 6). This information is used
by the PCM to modify air/fuel mixture and turbo-
charger boost level.
ENGINE COOLANT TEMPERATURE SENSORÐPCM
INPUT
The coolant temperature sensor is a variable resis-
tor with a range of -40ÉC to 128ÉF (-40ÉF to 265ÉF).
The sensor is installed into the thermostat housing
(Fig. 7). The PCM supplies 5.0 volts to the coolant temper-
ature sensor. The sensor provides an input voltage to
the PCM. The PCM determines engine operating
temperature from this input. As coolant temperature
varies, the sensor resistance changes resulting in a
different input voltage to the PCM. Based on the coolant sensor and charge air temper-
ature sensor inputs the PCM changes certain operat-
ing schedules until the engine reaches operating
temperature. While the engine warms up, the PCM
demands slightly richer air-fuel mixtures, lower
boost levels, revised spark advance and higher idle
speeds.
Fig. 5 Camshaft Position Sensor Location
Fig. 6 Charge Air Temperature Sensor
Fig. 4 Camshaft Gear
14 - 86 FUEL SYSTEMS Ä

CRANKSHAFT POSITION SENSORÐPCM INPUT
The crankshaft position sensor (Fig. 8) senses slots
cut into the flywheel. There ar e a 2 sets of slots.
Each set contains 4 slots, for a total of 8 slots (Fig.
9). Basic timing is set by the position of the last slot
in each group. Once the PCM senses the last slot, it
determines crankshaft position (which piston will
next be at TDC) from the camshaft position sensor
input. The 4 pulses generated by the crankshaft po-
sition sensor represent the 69É, 49É, 29É, and 9É BTDC
marks. It may take the PCM one engine revolution
to determine crankshaft position. The Turbo III en-
gine uses a fixed ignition system. Base timing is not
adjustable.
The PCM uses the crankshaft position sensor input
to determine injector sequence and ignition timing.
Once crankshaft position has been determined, the
PCM begins energizing the injectors in sequence. The crankshaft position sensor is located in the
transaxle housing, below the throttle body (Fig. 10).
The bottom of the sensor is positioned next to the
drive plate. The distance between the bottom of sensor and the drive plate is critical to the oper-
ation of the system. When servicing the crank-
shaft position sensor, refer to the 2.2L Turbo III
Multi-Port Fuel InjectionÐService Procedures
section in this Group.
KNOCK SENSORÐPCM INPUT
The knock sensor generates a signal when spark
knock occurs in the combustion chambers. The sensor
can detect detonation in the cylinders. The sensor
provides information used by the PCM to modify
spark advance and boost schedules in order to elimi-
nate detonation. The knock sensor is installed into the engine, be-
hind the PCV breather/separator (Fig. 11).
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSORÐPCM INPUT
The PCM supplies 5 volts to the MAP sensor. The
Map sensor converts intake manifold pressure into
voltage. The PCM monitors the MAP sensor output
voltage. As vacuum increases, MAP sensor voltage
decreases proportionately. Also, as vacuum decreases,
MAP sensor voltage increases proportionately.
Fig. 7 Coolant Temperature Sensor
Fig. 8 Crankshaft Position Sensor
Fig. 9 Timing Slots
Fig. 10 Crankshaft Position Sensor Location
Ä FUEL SYSTEMS 14 - 87