1982 CHEVROLET CAMARO ignition

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 577
MALFUNCTION INDICATOR LAMP
The primary function of the MIL is to adv
ise the operator and the technician that
a fault is detected, and, in most cases, a code is stored. Under normal
conditions, the malfunction indicator la mp will illuminate when the ignition is
turned ON. Once the engine is started and running, the ECM will perform a
system check and extinguish the lamp if no fault is found.
Additionally, the lamp can be used to retrieve stored codes after the system is
placed in the Diagnostic Mode. Codes ar e transmitted as a series of flashes
with short or long pauses. When the syst em is placed in the Field Service
Mode, the dash lamp will indicate open loop or closed loop function to the
technician.
INTERMITTENTS
If a fault occurs intermittently, such as a loose connector pin breaking contact
as the vehicle hits a bump, the ECM will note the fault as it occurs and energize
the dash warning lamp. If the problem se lf-corrects, as with the terminal pin
again making contact, the dash lamp will extinguish after 10 seconds but\
a code
will remain stored in the ECM memory.
When an unexpected code appe ars during diagnostics, it may have been set
during an intermittent failure that self-c orrected; the codes are still useful in
diagnosis and should not be discounted.
OXYGEN SENSOR
OPERATION
An oxygen sensor is used on all models. The sensor protrudes into the exhaust
stream and monitors the oxygen content of the exhaust gases. The difference
between the oxygen content of the exhaust gases and that of the outside air
generates a voltage si gnal to the ECM. The ECM monitors this voltage and,
depending upon the value of the signal rece ived, issues a command to adjust
for a rich or a lean condition.
No attempt should ever be made to meas ure the voltage output of the sensor.
The current drain of any conventional vo ltmeter would be such that it would
permanently damage the sensor.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 582
REMOVAL & INSTALLATION
On some models it may be necessary
to remove the air inlet assembly.
1. Disconnect the negative battery cable. Disconnect the IAC valve
electrical wiring.
2. Remove the IAC valve by performing the following: a. On thread-mounted units, use a 1
1/4 inch (32mm) wrench.
b. On flange-mounted units, remove the mounting screw assemblies.
3. Remove the IAC valve ga sket or O-ring and discard.
To install: 4. Clean the mounting surfaces by performing the following:
a. If servicing a thread-mounted valve, remove the old gasket material from the surf ace of the throttle body to ensure proper
sealing of the new gasket.
b. If servicing a flange-mounted valve, clean the IAC valve surfaces on the throttle body to assure pr oper seal of the new O-ring and
contact of the IAC valve flange.
5. If installing a new IAC valve, meas ure the distance between the tip of the
IAC valve pintle and the mounting flange. If the distance is greater than
1.102 inch (28mm), use finger pressure to slowly retract the pintle. The
force required to retract the pintle of a new valve will not cause damage
to the valve. If reinstalling the origin al IAC valve, do not attempt to adjust
the pintle in this manner.
6. Install the IAC valve into the thro ttle body by performing the following:
a. With thread-mounted valves, in stall with a new gasket. Using a
1
1/4 inch (32mm) wrench, tighten to 13 ft. lbs. (18 Nm).
b. With flange-mounted valves, lubricate a new O-ring with
transmission fluid and install on the IAC valve. Install the IAC
valve to the throttle body. Inst all the mounting screws using a
suitable thread locking compound. Tight en to 28 inch lbs. (3 Nm).
7. Connect the IAC valve electrical wiring.
8. Connect the negative battery cable.
9. No physical adjustment of the IAC valve assembly is required after installation. Reset the IAC valve pintle position by performing the
following:
a. Depress the accelerator pedal slightly.
b. Start the engine and run for 5 seconds.
c. Turn the ignition switch to the OFF position for 10 seconds.
d. Restart the engine and check for proper idle operation.

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MANIFOLD ABSOLUTE PRESSURE SENSOR
OPERATION
The MAP sensor measures the changes in
intake manifold pressure, which
result from engine load/ speed changes and converts this information to a
voltage output. The MAP sensor reading is the opposite of a vacuum gauge
reading: when manifold pressu re is high, MAP sensor value is high and vacuum
is low. A MAP sensor will produce a low output on engine coast-down with a
closed throttle while a wide open throttle will produce a high output. The high
output is produced because the pressure inside the manifold is the same as
outside the manifold, so 100 percent of t he outside air pressure is measured.
The MAP sensor is also used to meas ure barometric pressure under certain
conditions, which allows the ECM to autom atically adjust for different altitudes.
The MAP sensor changes the 5 volt signal supplied by the ECM, which reads
the change and uses the information to cont rol fuel delivery and ignition timing.

Fig. 1: MAP sensor
REMOVAL & INSTALLATION 1. Disconnect the negative battery cable.
2. Disconnect the vacuum connection.
3. Release the electrical wiring lo cking tab and disconnect the connector.
4. Remove the bolts or release the MAP sensor locking tabs and remove
the sensor.
To install: 5. Install the bolts or snap sensor onto the bracket.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 592

Fig. 2: Mass Air Flow sensor mounting, all models similar
KNOCK SENSOR
OPERATION
The knock sensor is usually mounted to the right lower side of the engine block.
When spark knock or pinging is present, the sensor produces a voltage signal
which is sent to the ECM. The ECM will then retard the ignition timing based on
these signals.

Fig. 1: Knock sensor

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 594
REMOVAL & INSTALLATION
1. Disconnect the negative battery cable.
2. Raise and safely support the vehicle.
3. Disconnect the VSS electrical wiring.
4. Remove the retaining bolt.
5. Have a clean container to catch the transmission fluid and remove the
VSS.
6. Remove and discard the O-ring.
To install: 7. Lubricate a new O-ring with a thin f ilm of transmission fluid. Install the O-
ring and VSS.
8. Install the retaining bolt.
9. Connect the electrical wiring.
10. Lower the vehicle.
11. Connect the negative battery cable.
12. Refill transmission to proper level.
TROUBLE CODES

SELF DIAGNOSTICS
READING CODES
The following procedure applies to mode ls with the 12 pin diagnostic connector
only.
1. Turn the ignition switch OFF. Locate the Assembly Line Diagnostic Link
(ALDL), usually under the instrument panel. It may be within a plastic
cover or housing labeled DIAGNOSTIC CONNECTOR. This link is used
to communicate with the ECM.
2. Use a small jumper wire to connect Terminal B of the ALDL to Terminal
A. As the ALDL connector is viewed from the front, Terminal A is on the
extreme right of the upper row; Terminal B is second from the right on
the upper row.
3. After the terminals are connected, turn the ignition switch to the ON
position but do not start the engine. T he dash warning lamp should begin
to flash Code 12. The code will disp lay as one flash, a pause and two
flashes. Code 12 is not a fault code. It is used as a system
acknowledgment or handshake code; its presence indicates that the
ECM can communicate as requested. Code 12 is used to begin every
diagnostic sequence.
4. After Code 12 has been transmitted 3 times, the fault codes, if any, will
each be flashed in the same manner th ree times. The codes are stored
and transmitted in numeric order from lowest to highest.
The order of codes in the memory does not indicate the order of occurrence.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 595
5. If one or more codes are stored,
record them. At the end of the
procedure, perform a visual and physical check of each system.
6. Switch the ignition OFF when finished with code retrieval.

Fig. 1: Diagnostic connector lo cation shown with a 12 pin connector
VISUAL AND PHYSICAL UNDERHOOD INSPECTION
A detailed examinatio n of connectors, wiring and va cuum hoses can often lead
to a repair without further diagnosis. This step relies on the skill of the
technician performing it; a careful inspec tor will check the undersides of hoses
as well as the integrity of hard-to-reac h hoses blocked by the air cleaner or
other component. Wiring should be check ed carefully for any sign of strain,
burning, crimping, or terminal pull-out from a connector. Checking connectors at
components or in harnesses is required; usually, pushing them together will
reveal a loose fit. It is important to note that the fault code indicates a fault or
loss of signal within that system, not necessarily the specific component. Due to
the intricacy of the systems and the spec ial testing equipment required, it is

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 596
recommended to have a qualified technici
an perform any further testing, if
needed.
FIELD SERVICE MODE
On fuel injected models, if the ALDL terminal B is grounded to terminal A with
the engine running, the system enters the Field Service Mode. In this mode, the
MIL will indicate whether the system is operating in open loop or closed loop.
If working in open loop, t he MIL will flash rapidly 2
1/2 times per second. In
closed loop, the flash rate slows to once per second. Additionally, if the system
is running lean in closed loop, the lamp will be off most of the cycle. A rich
condition in closed loop will cause the lamp to remain lit for most of the one
second cycle.
When operating in the Field Service M ode, additional codes cannot be stored
by the ECM. The closed loop timer is bypassed in this mode.
CLEARING CODES
Stored fault codes may be erased from me mory at any time by removing power
from the ECM for at least 30 seconds. It may be necessary to clear stored
codes during diagnosis to check for any re currence during a test drive, but the
stored should be written dow n when retrieved. The codes may still be required
for subsequent troubleshooting. Whenever a repair is complete, the stored
codes must be erased and the vehicle te st driven to confirm correct operation
and repair.
The ignition switch must be OFF any ti me power is disconnected or restored to
the ECM. Severe damage may result if this precaution is not observed.
Depending on the electric di stribution of the particular vehicle, power to the
ECM may be disconnected by removing the ECM fuse in the fusebox or
disconnecting the inline EC M power lead at the positive battery terminal.
Disconnecting the negative battery cable to clear codes will achieve the desired
result, but this will also clear other me mory data in the vehicle such as radio
presets or seat memory.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 628
SPARK PLUG HEAT RANGE
Spark plug heat range is
the ability of the plug to dissipate heat. The longer the
insulator (or the farther it extends in to the engine), the hotter the plug will
operate; the shorter the insulator (the cl oser the electrode is to the block's
cooling passages) the cooler it will operate. A plug that absorbs little heat and
remains too cool will quickly accumulate deposits of oil and carbon since it is
not hot enough to burn them off. This leads to plug fouling and consequently to
misfiring. A plug that absorbs too much heat will have no deposits but, due to
the excessive heat, the electrodes will burn away quickly and might possibly
lead to preignition or other ignition probl ems. Preignition takes place when plug
tips get so hot that they gl ow sufficiently to ignite the air/fuel mixture before the
actual spark occurs. This early igniti on will usually cause a pinging during low
speeds and heavy loads.

Fig. 3: Spark plug heat range
The general rule of thumb for choosing the correct heat range when picking a
spark plug is: if most of your driving is long distanc e, high speed travel, use a
colder plug; if most of your driving is stop and go, use a hotter plug. Original
equipment plugs are general ly a good compromise between the 2 styles and
most people never have the need to change their plugs from the factory-
recommended heat range.
REMOVAL & INSTALLATION
A set of spark plugs usually requi res replacement after about 20,000-30,000
miles (32,000-48,000 km), depending on y our style of driving. In normal
operation plug gap increases about 0.001 in. (0.025mm) for every 2500 miles
(4000 km). As the gap increases, the plug' s voltage requirement also increases.
It requires a greater voltage to jump t he wider gap and about two to three times