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.
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.
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.
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.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 692
IDLE AIR VALVE
A cover is in place over t
he idle air bleed valve. Also , the access holes to the
idle mixture needles are s ealed with hardened plugs. This is done to seal the
factory settings, during original equipment production. These items are NOT to
be removed unless required for cleaning, part replacement, improper dwell
readings or if the System Performance Check indicates the carburetor is the
cause of the trouble.
ROCHESTER E4ME AND E4MC
1. With engine OFF, cover the internal bowl vents and inlet to bleed valve
and the carburetor air intakes with maski ng tape. This is done to prevent
metal chips from entering.
2. Carefully drill rivet head of idle air bleed cover, with 0.110 in. (2.8mm) drill bit.
3. Remove rivet head and all pieces of rivet.
4. Lift cover off air bleed valve and bl ow out any metal shavings, or use a
magnet to remove excess metal.
CAUTION - Always wear eye protection when using compressed air.
5. Remove masking tape.
6. Start engine and allow it to reac h normal operating temperature.
7. Disconnect the vacuum hose from t he canister purge valve and plug it.
8. While idling in D for automatic transmission or N for manual
transmission, slowly turn the valve c ounterclockwise or clockwise, until
the dwell reading varies within the 25-35 degree range, attempting to be
as close to 30 degrees as possible.
Perform this step carefully. The air bleed valve is very sensitive and should be
turned in
1/8 turn increments only.
9. If the dwell reading d oes not vary and is not within the 25-35 degree
range, it will be necessary to remove the plugs and to adjust the idle
mixture needles.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 696
Fig. 28: Lean mixture and idle mixture screw adjustment
E4MC CARBURETOR (HOT AIR CHOKE) 1. Using tool J-29030-B, BT-7610-B, or equivalent, turn each idle mixture
needle clockwise until lightly seated, then turn each mixture needle
counterclockwise 3 turns.
2. Reinstall carburetor on engine, using a new flange mounting gasket, but
do not install air cleaner or gasket at this time.
3. Disconnect vacuum hose to c anister purge valve and plug it.
4. Connect the positive lead of a dwell me ter to the mixture control solenoid
test lead (green connector). Connect the other lead to ground. Set the
meter to the 6 cylinder position.
5. Start engine and allow it to reac h normal operating temperature.
6. While idling in D ( N for manual transmission), adjust both mixture
needles equally, in
1/8 turn increments, until dwell reading varies within
the 25-35 degree range, attempting to be as close to 30 degrees as
possible.
7. If reading is too low, turn mixtur e needles counterclockwise. If reading is
too high, turn mixture needl es clockwise. Allow time for dwell reading to
stabilize after each adjustment.
After adjustments are complete, seal t he idle mixture needle openings in the
throttle body, using silicone sealant, RTV rubber, or equivalent. The sealer is
required to discourage unnece ssary readjustment of the setting and prevent fuel
vapor loss in that area.
8. On vehicles without a carburetor -mounted Idle Load Compensator (ILC) ,
adjust curb idle speed if necessary.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 719
11. Lubricate the new large O-ring with cl
ean engine oil and install it directly
over the backup washer. Be sure t he O-ring is seated properly and is
flush with the top of the fuel meter body surface.
12. Lubricate the new small O-ring with clean engine oil and install it on the
nozzle end of the injector. Push t he O-ring on far enough to contact the
filter.
WARNING - Do not attempt to reverse this procedure and install the backup
washer and O-ring after the injector is located in the cavity. To do so will
prevent proper seating of the O-ring in th e cavity recess which could result in a
fuel leak and possible fire.
13. Install the injector by aligning the raised lug on the injector base with the
notch cast into the fuel meter body . Push down on the injector making
sure it is fully seated in the cavity. In jector installation is correct when the
lug is seated in the notch and the electrical terminals are parallel to the
throttle shaft.
14. Using new gaskets on the fuel mete r cover and a new dust seal, install
the cover to the fuel meter body. Use an appropriate thread locking
compound on the cover attaching screws.
15. Connect the injector electrical c onnector by pushing straight down until
seated firmly in place.
16. Connect the negative battery cable.
17. With the engine OFF and the igniti on ON, check for fuel leaks.
18. Install the air cleaner.
ADJUSTMENTS
MINIMUM IDLE SPEED
Minimum idle speed should only be adjus ted when installing a replacement
throttle body. The idle stop screw is used to regulate the minimum idle speed of
the engine. The throttle body is adjusted at the factory, then covered with a cap
or plug to discourage unnecessary readjustment.
2.5L ENGINES 1. Remove the air cleaner and pl ug the THERMAC vacuum port.
2. Disconnect the TV cable from the th rottle control bracket to allow access
to the idle adjustment screw.
3. Remove the throttle stop screw plug or cap.
4. Connect a tachometer to the engine.
5. Disconnect the Idle Air Control (IAC) valve connector.
6. Start the engine with the transmi ssion in PARK (auto transmission) or
NEUTRAL (manual transmission) and allow the engine speed to
stabilize. All accessories (A/C, rear defogger, etc.) should be OFF.
7. Install tool J-33047 in t he idle air passage of the throttle body. Be certain
that the tool seats fully in t he passage and no air leaks exist.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 720
8. Using a number 20 Torx® bit, turn
the throttle stop screw until the engine
speed is 475-525 rpm in PARK (aut o transmission) or 450-500 rpm in
NEUTRAL (manual transmission).
9. Stop the engine and remove tool J-33047 from the throttle body.
10. Reconnect the TV cable to the throttle control bracket.
11. Reconnect the IAC valve connector.
12. Use silicone sealant to co ver the throttle stop screw.
13. Reinstall the air cleaner.
Fig. 6: Installing tool J-33047
5.0L ENGINES 1. Remove the idle stop screw plug or cap.
2. Ground the diagnostic connector (ALDL).
3. Turn the ignition ON and wait 45 seconds, DO NOT start the engine.
4. Disconnect the idle air control connector with the ignition ON.
5. Remove the ground from the di agnostic connector and disconnect the
distributor set-timing connector.
6. Connect a tachometer to the engine.
7. Place the transmission in PARK (auto transmission) or NEUTRAL
(manual transmission). Start and run the engine until it reaches normal
operating temperature.
It is important that the distributor set- timing connector be disconnected to fix the
spark advance at base timing. This elim inates the possibility of changes in
engine speed due to variations in timing.