
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.