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GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 657
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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GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 658
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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GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 659
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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GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 660
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.
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GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 661
Fig. 2: Idle speed adjustm ents - 2-bbl carburetor (with air conditioning)
4-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). Se t the parking brake. Connect a
tachometer to the dist ributor connector.
2. Place the transmission in DRIVE for automatic transmission, or
NEUTRAL for manual transmission.
3. De-energize the idle speed solenoid by disconnecting the electrical lead.
4. Set the basic idle speed rpm by turning the idle speed screw.
5. Connect a jumper wire from a 12-vo lt power supply to the solenoid.
6. Open the throttle partially to ensure that the solenoid plunger is fully
extended, and allow the throttle lever to close on the plunger.
7. Turn the solenoid plunger to adj ust to the specified rpm. After
adjustment, disconnect the jumper wire and reconnect the solenoid
electrical lead.
8. Remove the tachometer and install the air cleaner.
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GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 662
Fig. 3: Idle speed adjustm ents - 4-bbl carburetor
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). Se t the parking brake. Connect a
tachometer to the dist ributor connector.
2. Place the transmission in DRIVE for automatic transmission, or
NEUTRAL for manual transmission. Tu rn the air conditioning OFF.
3. De-energize the idle speed solenoid by disconnecting the electrical lead.
4. Set the basic idle speed rpm by turning the idle speed screw. After
adjustment, reconnect the solenoid electrical lead.
5. Disconnect the electrical lead from the A/C compressor and turn the A/C
switch ON.
6. Open the throttle partially to ensure that the solenoid plunger is fully
extended, and allow the throttle lever to close on the plunger.
7. Turn the solenoid plunger to adj ust to the specified rpm. After
adjustment, reconnect the A/C co mpressor lead and turn the air
conditioning OFF.
8. Remove the tachometer and install the air cleaner.
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GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 663
SPECIFICATIONS CHARTS
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