light CHEVROLET CAMARO 1982 Repair Guide

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 639
In the HEI system, as in other electr
onic ignition systems, the breaker points
have been replaced wit h an electronic switch - a tr ansistor - which is located
within the ignition module. This switching transistor pe rforms the same function
the points did in a conventi onal ignition system; it simply turns the coil's primary
current on and off at the correct time. Essentially, electronic and conventional
ignition systems operate on t he same principle.
The module which houses the switching transistor is controlled (turned on and
off) by a magnetically gener ated impulse induced in the pickup coil. When the
teeth of the rotating timer align with t he teeth of the pole piece, the induced
voltage in the pickup coil signals the elec tronic module to open the coil primary
circuit. The primary current then decreases, and a high voltage is induced in the
ignition coil secondary windings, which is then directed through the rotor and
high voltage leads (spark plug wires) to fire the spark plugs.
In essence, the pickup coil module system simply replaces the conventional
breaker points and condenser. The condenser found within the distributor is for
radio suppression purposes only and has nothing to do with the ignition
process. The ignition module automatically controls the dwell period, increasing
it with increasing en gine speed. Since dwell is co ntrolled in this manner, it
cannot be adjusted. The module itse lf is non-adjustable/non-repairable and
must be replaced if found defective.
SYSTEM PRECAUTIONS
Before proceeding with troubleshooting, ta ke note of the following precautions:
TIMING LIGHT USE
Care should be exercised when connec ting a timing light or other pick-up
equipment. Do not force anything between the boots and wiring, or through the
silicone jacket. Connections should be made in parallel using an adapter.
Inductive pickup timing lights are the bes t kind to use with the ignition systems
covered by this information.
SPARK PLUG WIRES
The plug wires used with these systems are of a different construction than
conventional wires. When replacing them, make sure you get the correct wires,
since conventional wires will not carry the voltage. Also, handle the wires
carefully to avoid cracking or splitti ng them, and NEVER pierce the wires.
TACHOMETER USE
Not all tachometers will operate or indi cate correctly when used on an HEI or
C
3I system. While some tachometers ma y give a reading, this does not
necessarily mean the reading is correct. In addition, some tachometers hook up
differently from others. If you cannot fi gure out whether or not your tachometer
will work on your car, check with the tachometer manufacturer.

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If, however, there is no spark or a weak
spark, then further ignition system
testing will have to be done. Troubleshooting techniques fall into various
categories, depending on t he nature of the problem and the system being
tested. Categories will include symptom s such as the engine cranks, but will not
start or the engine runs rough.
HEI SYSTEM
When testing the HEI system, there are 2 major categories of problems, (1)
Engine cranks, but will not star t or (2) Engine runs, but runs rough or cuts out.
If the engine will not start, perform a spar k test as described earlier. This will
narrow the problem area down considerab ly. If no spark occurs, check for the
presence of normal battery voltage at the battery ( BAT) terminal on the ignition
coil. The ignition switch must be in the ON position for this test. Either a
voltmeter or a test light wire may be us ed for this test. Connect the test light
wire to ground and the probe end to the BAT terminal at the coil. If the light
comes on, you have voltage to the distribut or and/or spark plug wires. If the light
fails to come on, this indicates an open circuit in the ignition primary wiring
leading to the distributor. In this case , you will have to check wiring continuity
back to the ignition switch using a test li ght. If there is battery voltage at the BAT
terminal, but no spark at the plugs, t hen the problem probably lies within the
distributor assembly.
If, on the other hand, the engine starts, but runs roughly or cuts out, make sure
the plug wires are in good shape first. There should be no obvious cracks or
breaks. You can check the plug wires with an ohmmeter, but do not pierce the
wires with a probe. Check the chart for th e correct plug wire resistance. If the
plug wires are OK, remove the cap asse mbly and check for moisture, cracks,
chips, or carbon tracks, or any other hi gh voltage leads or failures. Replace the
cap if any defects are found. Make su re the timer wheel rotates when the
engine is cranked.
If the trouble has been narrowed down to t he units within the distributor, the
following tests can help pinpoint the defective component. An ohmmeter with
both high and low ranges shou ld be used. These tests are made with the cap
assembly removed and the battery wir e disconnected. If a tachometer is
connected to the TACH terminal, disconnect it before making these tests.
IGNITION COIL
EXTERNALLY MOUNTED 1. Disconnect the coil wires and se t the ohmmeter on the high scale.
2. Connect the ohmmeter to the ignition co il as illustrated in Step 1 of the
accompanying figure.
3. The ohmmeter should read near infinite or very high.

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spark plug must fire 5° before each pist
on reaches TDC. This only holds true,
however, when the engine is at idle speed.
As the engine speed increases, the pist ons go faster. The spark plugs have to
ignite the fuel even sooner if it is to be completely ignited when the piston
reaches TDC.
If the ignition is set too far advanced (B TDC), the ignition and expansion of the
fuel in the cylinder will occu r too soon and try to force the piston down while it is
still traveling up. This causes engine ping. If the ignition spark is set too far
retarded, after TDC (ATDC), the pi ston will have already passed TDC and
started on its way down when the fuel is igni ted. This will cause the piston to be
forced down for only a portion of its trav el, resulting in poor engine performance
and lack of power.
When timing the engine, the Number 1 pl ug wire should be used to trigger the
timing light. On engines where timing is adjustable, the notch for the No. 1
cylinder is usually scribed across all th ree edges of the double sheaf pulley.
Another notch located 180° away from t he No. 1 cylinder notch is scribed only
across the center section of the pulley to make it distinguishable from the No. 1
cylinder notch.
There are two basic types of timing light s available. The first type of light
operates from the car's battery. Two al ligator clips connect to the battery
terminals, while a third wire connects to the spark plug with an adapter or to the
spark plug wire with an inductive pickup. This type of light is more expensive,
but the xenon bulb provides a nice bright flash which can even be seen in
sunlight. The second type replaces the battery source with 110-volt house
current. Some timing lights have other func tions built into them, such as dwell
meters, tachometers, or re mote starting switches. These are convenient, in that
they reduce the tangle of wires under t he hood, but may duplicate the functions
of tools you already have.
Because this car uses electronic ignition, you should use a timing light with an
inductive pickup. This pickup simply cl amps around the Number 1 spark plug
wire (in this case, the coil wire), elimin ating the adapter. It is not susceptible to
crossfiring or false triggering, which ma y occur with a conventional light due to
the greater voltages produc ed by these systems.
ADJUSTMENT
When adjusting the timing, refer to the instructions on the emission control
sticker inside the engine compartment. If th e instructions on the label disagree
with the procedure listed below, follo w the instructions on the label.
1982-87 VEHICLES 1. Locate the timing marks on the cran kshaft pulley and the front of the
engine.

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2. Clean off the marks and coat them wit
h white paint or chalk, if necessary,
so that they may be seen.
3. Run the engine until it reaches no rmal operating temperature, then shut
off the engine.
4. With the ignition OFF, connect a ta chometer to the distributor, and a
timing light with an inductive pickup lead to the No. 1 spark plug wire.
WARNING - Never pierce a secondary ignition wire in order to connect a timing
light. A pierced wire may lead to engine misfiring and driveability problems.
5. To properly set the ignition timing , the EST must be placed in the bypass
mode. a. On the 2.5L engine, refer to t he emission control label for the
procedure.
If the label is missing or unreadable, c ontact your Chevrolet dealer for a
replacement.
b. On 2.8L and 5.0L ca rbureted engines, disconnect the 4-wire EST
connector at the distributor. (Fault code 42 may be set in ECM memory,
and must be cleared once the procedur e is completed). Proceed to Step
7.
c. On 2.8L, 5.0L and 5.7L fuel inje cted engines, with the engine RUNNING
and all accessories off, use a jumper wire to connect diagnostic terminal
B and ground terminal A of the 12-terminal Assembly Line Diagnostic
Link (ALDL) usually located under t he left side of the instrument panel.
DO NOT disconnect the 4-wir e EST connector at the distributor. Aim the
timing light at the timing mark; the li ne on the balancer or pulley will line
up with the timing mark. Increase engine speed and check for timing
advance. If the timing still advances with engine speed, perform Step 6. If
timing does not advance with engi ne speed, proceed to Step 7.
If timing advances with engine speed, it will be necessary to disconnect the
single-wire Set Timing connector. (Faul t code 42 may be set in ECM memory,
and must be cleared once the procedure is completed).
6. Remove the jumper wire from t he ALDL, and shut off the ignition.
Disconnect the Set Timing connector, usually located under the plastic
cover above the heater unit, in the engi ne compartment. (The wire in this
connector is normally Tan/Black.)
7. With the engine running and all accessories off, aim the light at the timing
mark. The line on the balancer or pulle y will line up with the timing mark.
If a change in timing is necessary, loosen the hold-down clamp bolt at
the base of the distributor . While observing the timing mark, rotate the
distributor slightly unt il the line indicates the correct timing. Use the
timing specification on the emi ssion control label in the engine
compartment. If this label is missi ng or damaged, refer to the Tune-Up
Specifications chart in this Section.

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8. Once the timing is set to specific
ation, tighten the distributor hold-down
clamp. Recheck the timing to make su re it did not change while the bolt
was being tightened.
9. Remove the jumper wire from the ALDL connector, if applicable, with the
engine still running. (Usually, if this is performed before the engine is
shut off, no trouble codes will be stored.)
10. Turn the engine OFF, then remove the timing light and tachometer.
Reconnect the number 1 spark plug wire, if disconnected.
11. Attach the 4-wire EST connector at the distributor, or reconnect the Set
Timing connector, if applicable.
12. Check for fault code 42, and clear, if necessary, by disconnecting the
negative battery cable for at least 30 seconds.
To prevent ECM damage, the key must be in the OFF position when
disconnecting or reconnecting battery cables.
1988-90 VEHICLES
When adjusting the timing, refer to the instructions on the emission control
sticker inside the engine compartment. If th e instructions on the label disagree
with the procedure listed below, follo w the instructions on the label.
1. Locate the timing marks on the cran kshaft pulley and the front of the
engine.
2. Clean off the marks and coat them with white paint or chalk, so that they
may be easily seen.
3. Run the engine until it reaches no rmal operating temperature, then shut
off the engine.
4. With the ignition OFF, connect a ta chometer to the distributor, and a
timing light with an inductive pickup lead to the No. 1 spark plug wire.
WARNING - Never pierce a secondary ignition wire in order to connect a timing
light. A pierced wire may lead to engine misfiring and driveability problems.
5. Start the engine. With the engine running and all accessories off, use a
jumper wire to connect diagnostic terminal B and ground terminal A of
the 12-terminal Assembly Line Diagnostic Link (ALDL), located under the
instrument panel.
If jumping the ALDL terminals does not prevent timing advance, the EST
bypass wire will have to be disconnected instead.
6. Aim the timing light at the timing mark. The line on the balancer or pulley
will line up with the timing mark. If a change in timing is necessary,
loosen the hold-down clamp bolt at t he base of the distributor. While
observing the timing mark, rotate the distributor slightly until the line
indicates the correct timing. Use t he timing specification on the emission
control label in the engine compartm ent. If this label is missing or
damaged, refer to the Tune- Up Specifications chart in this Section.

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7. Once the timing is set to specific
ation, tighten the distributor hold-down
clamp. Recheck the timing to make su re it did not change while the bolt
was being tightened.
8. With the engine still running, unground the diagnostic terminal.
(Ungrounding the diagnostic terminal while the engine is still running will
usually prevent trouble c odes from being stored.)
9. Turn the engine OFF and remove the timing light and tachometer.
Reconnect the number 1 spark plug wire, if disconnected.

Fig. 1: Grounding the diagnostic termi nal in order to set ignition timing
1991-92 VEHICLES
When adjusting the timing, refer to the instructions on the emission control
sticker inside the engine compartment. If th e instructions on the label disagree
with the procedure listed below, follo w the instructions on the label.
1. Locate the timing marks on the cran kshaft pulley and the front of the
engine.
2. Clean off the marks and coat them wit h white paint or chalk, if necessary,
so that they may be seen.
3. Run the engine until it reaches no rmal operating temperature, then shut
off the engine.
4. With the ignition OFF, connect a tachometer to the distributor, and the
pickup lead of an inductive timing li ght to the No. 1 spark plug wire.

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Connect the timing light power leads
according to the manufacturer's
instructions.
WARNING - Never pierce a secondary ignition wire in order to connect a timing
light. A pierced wire may lead to engine misfiring and driveability problems.
5. Start the engine. With the engine running at normal operating
temperature and all accessories OFF, disconnect the EST bypass
connector.
An ECM code will be set when the EST bypass connector is disconnected.
6. Aim the timing light at the timing mark. The line on the balancer or pulley
will line up with the timing mark. If a change in timing is necessary,
loosen the hold-down clamp bolt at t he base of the distributor. While
observing the timing mark, rotate the distributor slightly until the line
indicates the correct timing. Use t he timing specification on the emission
control label in the engine compartm ent. If this label is missing or
damaged, refer to the Tune- Up Specifications chart in this Section.
7. Tighten the distributor hold-down bolt and recheck the ignition timing to
make sure the distributor was not moved when the bolt was tightened.
8. Turn the engine OFF and remove the timing light and tachometer.
Reconnect the number 1 spark plug wire, if disconnected.
9. Connect the EST bypass connector , then check for and clear the ECM
code by disconnecting the negative battery cable for at least 30 seconds.
To prevent ECM damage, the key must be in the OFF position when
disconnecting or reconnecting battery cables.

Fig. 2: EST bypass connector

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VALVE LASH

All models utilize a hydraulic valve lifter system to obtain zero lash. No periodic
adjustment is necessary. An initial adjustm
ent is required anytime that the lifters
are removed or the valve tr ain is disturbed. This procedure is covered in Engine
& Engine Overhaul .

IDLE SPEED AND MIXTURE ADJUSTMENTS

Mixture adjustments are factory set and sealed; no adjustment attempt should
be made, except by an aut horized GM dealer or reputable shop equipped with
the necessary equipment.

IDLE SPEED
2-BBL CARBURETOR
WITHOUT AIR CONDITIONING
The engine must be running in "Closed Loop" mode (engine fully warmed) when
making all idle speed adjustments. In this mode, the oxygen sensor affects
control of the fuel delivery.
1. Refer to the emission label on the vehicle and prepare the engine for
adjustments (set the timing). Remove the air cleaner and set the parking
brake. Connect a tachometer to the distributor connector.
2. Place the transmission in DRIVE for automatic transmission, or
NEUTRAL for manual transmission; make sure that the solenoid is
energized.
3. Open the throttle slightly to allow the solenoid plunger to extend. Adjust
the curb idle speed to the specified rpm by turning the solenoid screw.
4. De-energize the solenoid by disconnecting the electrical lead.
5. Set the basic idle speed rpm by turning the idle speed screw. After
adjustment, reconnect the solenoid electrical lead.
6. Remove the tachometer and install the air cleaner.

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Fig. 1: Idle speed adjustm ents - 2-bbl carburetor (without air conditioning)
WITH AIR CONDITIONING
The engine must be running in "Closed Loop" mode (engine fully warmed) when
making all idle speed adjustments. In this mode, the oxygen sensor affects
control of the fuel delivery.
1. Refer to the emission label on the vehicle and prepare the engine for
adjustments (set the timing). Remove the air cleaner and set the parking
brake. Connect a tachometer to the distributor connector.
2. Place the transmission in DRIVE for automatic transmission, or
NEUTRAL for manual transmission. Tu rn the air conditioning OFF and
set the curb idle speed by turning the idle speed screw.
3. Disconnect the electrical lead at the A/C compressor, then turn the A/C
switch ON.
4. With the solenoid e nergized, open the throttle slightly to allow the
solenoid plunger to extend.
5. Turn the solenoid screw to adjust to the specified rpm. After adjustment,
reconnect the A/C compressor lead and turn the air conditioning OFF.
6. Remove the tachometer and install the air cleaner.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 670
the idle speed or mixture,
adjust the idle and mixture again when you are
finished.
Before you make any carburetor adjustment s make sure that the engine is in
tune. Many problems which are thought to be carburetor related can be traced
to an engine which is simply out-of-tune. Any trouble in these areas will have
symptoms like those of carburetor problems.
ADJUSTMENTS
FAST IDLE
ROCHESTER E2SE 1. Refer to the emission label and pr epare the vehicle for adjustment.
2. Place the fast idle screw on the highest step of the fast idle cam.
3. Turn the fast idle screw to obtain the fast idle speed.
ROCHESTER E4ME AND E4MC
The fast idle adjustment must be perform ed according to the directions of the
emissions label.
FLOAT AND FUEL LEVEL
ROCHESTER E2SE
1. Remove the air horn and gasket.
2. While holding the retainer in place, push the float down lightly against the
needle.
3. Place a measuring gauge on the float at the farthest point from the float
hinge.
4. To adjust, remove the float and bend the arm up or down. Also check the
float alignment.
5. Install the air horn and gasket.