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) 626
ENGINE PERFORMANCE AND TUNE-UP
TUNE-UP PROCEDURES
In order to extract the full measure of performance and economy from your
engine it is essential that it is properly tuned at regul ar intervals. A regular tune-
up will keep your Camaro's engine running smoothly and will prevent the
annoying breakdowns and poor perform ance associated with an untuned
engine.
A complete tune-up should be performed every 30,000 miles (48,000 km). This
interval should be halved if the car is operated under severe conditions such as
trailer towing, prolonged idling, start-and- stop driving, or if starting or running
problems are noticed. It is assumed that the routine maintenance described in
General Information & Maintenance has been kept up, as this will have a
decided effect on the result s of a tune-up. All of the applicable steps of a tune-
up should be followed in order, as the result is a cumulative one.
If the specifications on the underhoo d tune-up sticker in the engine
compartment of your car disagree with th e "Tune-Up Specifications" chart in this
Section, the figures on the sticker must be used. The sticker often reflects
changes made during t he production run.
SPARK PLUGS
A typical spark plug consists of a metal shell surrounding a ceramic insulator. A
metal electrode extends downward through the center of the insulator and
protrudes a small distance. Located at the end of the plug and attached to the
side of the outer metal shell is the side el ectrode. The side electrode bends in at
a 90 angle so that its tip is just pas t and parallel to the tip of the center
electrode. The distance between these two electrodes (measured in
thousandths of an inch or hundredths of a millimeter) is called the spark plug
gap.
The spark plug does not pr oduce a spark, but instead provides a gap across
which the current can arc. The coil produces anywhere from 20,000 to 50,000
volts (depending on the type and application) which travels through the wires to
the spark plugs. The current passes along the center electrode and jumps the
gap to the side electrode, and in doing so, ignites the air/fuel mixture in the
combustion chamber.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 656
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.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 699
Fig. 30: Idle load compensator components
THROTTLE POSITION SENSOR (TPS)
Before the throttle position sensor voltage output setting can be accurately
checked or adjusted the idle rpm mu st be within specifications. The plug
covering the TPS adjustment screw is used to provide a tamper-resistant design
and retain the factory setting during vehicl e operation. Do not remove the plug
unless diagnosis indicates t he TPS is not adjusted correct ly, or it is necessary
to replace the air horn assembly, float bowl, TPS, or TPS adjustment screw.
This is a critical adjustment that must be performed accurately to ensure proper
vehicle performance and contro l of exhaust emissions. Remove TPS plug if not
already removed.
Adjustment is required only if voltage is above the following readings, as the
ECM automatically zeros below 0.70 Volts.
1. Using a
5/64 in. (2mm) drill bit, carefully drill a hole in the steel or
aluminum plug. Be sure to drill only far enough to start a self tapping
screw, the approximat e drilling depth is
1/16-1/8 in. (1.6-3mm).
Use care in drilling so as not to damage the TPS adjustment screw head.
2. Start a long self tapping screw (No. 8 x
1/2 in.) into the drilled pilot hole in
the plug. Turn the screw in only enough to ensure a good thread
engagement in the drilled hole.
3. Place a suitable tool between the screw head and the air horn casting.
Then pry against the screw head to remove the plug. A small slide
hammer may also be used in this proc edure. Be sure to discard the plug
when it has been removed.
4. Connect a suitable digital voltmete r (J-29125 or equivalent) from the TPS
connector center terminal (B) to the bottom terminal (C).
Jumper wires for access can be made using terminals 12014836 and 12014837
or equivalent. Make jumper wires up with 16 gauge (1.0mm), 18 gauge (0.8mm)
or 20 gauge (0.5mm) wire approximately 6 in. (152mm) long.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 721
8. The idle speed should be 450-500 rpm, adjust as necessary.
WARNING - Correct minimum idle speed adj ustment is critical to vehicle
performance and component durability. Incorrect minimum idle speed
adjustment (too high) will caus e the IAC valve pintle to constantly bottom in it's
seat and result in early valve failure. If minimum idle speed is adjusted too low,
the vehicle may not start in cold weather or may stall during warm-up.
Turn the ignition OFF and reconnect the IAC motor connector.
9. Reconnect the distributor set-timing connector.
10. Use silicone sealant to co ver the throttle stop screw.
THROTTLE POSITION SENSOR (TPS)
1982-1983 2.5L TBI engines ar e equipped with an adjustable throttle position
sensor. This procedure should only be performed after replacing the TPS or
diagnosis leads to incorrect TPS adjustment.
1. Remove the throttle position sensor connector and install three jumper wires between the connector and the s ensor. Connect a digital voltmeter
to terminals B and C.
2. Turn the ignition ON. It should display bet ween 0.45-0.60 volts.
3. Adjust the TPS, if necessary, by loosening the attaching screws and
rotating the TPS.
4. Tighten the screws, remove the jumper wires with the ignition OFF and
reconnect the harness connector.
5. Start the engine and check fo r proper idle operation.
Fig. 7: TPS adjustment
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 743
MINIMUM IDLE SPEED
The minimum idle speed should onl
y be adjusted under two conditions:
If the throttle body has been replaced.
After every other possible cause for the in correct idle speed has been explored.
There are many possible causes for incorre ct idle speed, most of which require
a high level of diagnostic skill as well as expensive testing equipment. Check
the vehicle for vacuum leaks, incorrect valve or ignition timing, deposit
accumulation in the throttle bore or valve, sticking throttle linkage or bent throttle
valves. If the vehicle will still not idle pr operly after checking these areas, it
should be diagnosed by a professional.
1. Pierce the idle stop screw with an awl. Apply leverage to remove it.
2. Make sure the IAC valve is connect ed. Short the A and B terminals of the
ALDL connector together with a length of wire.
3. Turn the ignition to the ON positi on, but do not start the engine. Wait at
least 30 seconds before proceeding.
4. With the ignition ON, disconnect the IAC valve connector.
5. Separate the set-timing connector. Th is eliminates the possibility of
changes in engine speed due to variations of engine timing.
6. Start the engine and remove t he wire shorting the A and B terminals
together. It may be necessary to hold the throttle open slightly to prevent
the engine from stalling.
7. Allow the engine to reach no rmal operating temperature.
8. Adjust the idle speed to the following: a. 2.8L Engines - 450-550 rp m A/T or 550-650 rpm M/T
b. 3.1L Engines - Refer to the underhood emissions sticker
c. 5.0L and 5.7L TPI engines - 400-450 rpm.
If these figures differ from t hose on the underhood emissions
sticker, always follow the specifications on the emissions sticker.
9. Turn the ignition OFF and connect the IAC valve harness. On models up
to 1989, adjust the Throttle Position Sensor.
THROTTLE POSITION SENSOR (TPS) 1. Install three jumper wires betw een the TPS and the harness connector.
2. Use a digital voltmeter connected to terminals A and B of the TPS.
3. Turn the ignition switch ON , but do not start the engine.
4. Loosen the TPS attaching screws and adj ust the sensor to the following:
a. 2.8L Engines - 0.50-0.60 volts
b. 5.0L and 5.7L TPI Engines - 0.47-0.61 volts
5. Tighten the attaching screws, then check that the reading has not been
disturbed.
6. With the ignition OFF, remove the jumper wires. Reconnect the TPS
harness.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 810
Fig. 14: After the bearings are adjusted, install the dust cap by gently tapping on
the flange - DO NOT damage the c ap by hammering on the center
JUMP STARTING A DEAD BATTERY
Whenever a vehicle is jump started, pr ecautions must be followed in order to
prevent the possibility of personal inju ry. Remember that batteries contain a
small amount of explosive hydrogen gas which is a by-product of battery
charging. Sparks should always be av oided when working around batteries,
especially when attaching jumper cabl es. To minimize the possibility of
accidental sparks, follow the procedure carefully.
Fig. 1: Connect the jumper cables to the batteries and engine in the order
shown
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 811
CAUTION
- NEVER hook the batteries up in a series circuit or the entire
electrical system will go up in smoke, including the starter!
Vehicles equipped with a diesel engine may utilize two 12 volt batteries. If so,
the batteries are connected in a parallel circuit (positive terminal to positive
terminal, negative terminal to negative te rminal). Hooking the batteries up in
parallel circuit increases battery cranki ng power without increasing total battery
voltage output. Output remains at 12 vo lts. On the other hand, hooking two 12
volt batteries up in a series circuit (positive terminal to negative terminal,
positive terminal to negative terminal) incr eases total battery output to 24 volts
(12 volts plus 12 volts).
JUMP STARTING PRECAUTIONS
• Be sure that both batteries are of t he same voltage. Vehicles covered by
this information and most vehicles on the road today utilize a 12 volt
charging system.
• Be sure that both batteries are of the same polarity (have the same
terminal, in most cases NEGATIVE grounded).
• Be sure that the vehicles are not touching or a short could occur.
• On serviceable batteries, be sure the v ent cap holes are not obstructed.
• Do not smoke or allow sparks anywhere near the batteries.
• In cold weather, make sure the battery electrolyte is not frozen. This can
occur more readily in a battery that has been in a state of discharge.
• Do not allow electrolyte to c ontact your skin or clothing.
JUMP STARTING PROCEDURE 1. Make sure that the voltages of the 2 batteries are the same. Most
batteries and charging systems are of the 12 volt variety.
2. Pull the jumping vehicle (with t he good battery) into a position so the
jumper cables can reach the dead battery and that vehicle's engine.
Make sure that the ve hicles do NOT touch.
3. Place the transmissions of both vehicles in Neutral (MT) or P (AT), as
applicable, then firmly set their parking brakes.
If necessary for safety reasons, the hazard lights on both vehicles may be
operated throughout the entir e procedure without significantly increasing the
difficulty of jumping the dead battery.
4. Turn all lights and accessories OFF on both vehicles. Make sure the ignition switches on both vehicles are turned to the OFF position.
5. Cover the battery cell caps with a rag, but do not cover the terminals.
6. Make sure the terminals on both batte ries are clean and free of corrosion
or proper electrical connection wil l be impeded. If necessary, clean the
battery terminals before proceeding.
7. Identify the positive (+) and negat ive (-) terminals on both batteries.
8. Connect the first jumper cable to the positive (+) terminal of the dead
battery, then connect the other end of that cable to the positive (+)
terminal of the booster (good) battery.