In order to generate the most power, your 1991 Camaro's 5.7-liter engine's ignition system must fire the spark plugs at the right moment. It takes a few milliseconds from opening the coil primary circuit to the firing of the spark plug, so the original signal must come just before the piston reaches top dead center of the compression stroke. Ignition timing is measured in degrees before or after top dead center. The proper timing for your car is 6 degrees before top dead center.
Rotate the engine by briefly turning the key to "bump" the starter until the notch on the harmonic dampener -- the large pulley at the bottom front of the engine -- comes into view from the driver's side of the engine bay. Turn the key off and remove it from the ignition. Spray this pulley and the timing mark on the timing chain cover with the cleaner and wipe them clean with a rag. Mark the timing notch and the indicator with the chalk so the numbers are easier to read with the engine running.
Start and run the engine until it reaches normal temperature and shut it off. Connect the inductive pick-up (square-ish clamp) on the timing light to the No. 1 plug wire (driver's side front of the engine), and the red and black clips to the battery. Make sure all wires and cables are clear of moving parts.
Start the engine. Make sure all accessories are off. There is a wiring bundle near the firewall on the passenger side that has a single wire that runs to near the distributor. Disconnect the connector on this wire.
Aim the timing light at the crankshaft pulley from the driver's side and verify the location of the timing mark on the pulley in relation to the timing indicator on the engine. The optimal reading is 6 degrees before top dead center. If the reading is off, proceed to the next step.
Loosen the distributor hold-down clamp bolt by turning it counterclockwise with the distributor wrench. A 1/2-inch swivel socket on a 10-inch extension and ratchet will work also.
Rotate the distributor to advance or retard the timing. If the timing is 5 degrees or less before top dead center, rotate the distributor counterclockwise slowly to advance the timing. If the timing is more than 6 degrees before top dead center, rotate the distributor clockwise to retard it. Once the proper timing is set, tighten the hold-down clamp bolt. Check the timing again to make sure it wasn't moved during tightening.
Shut the engine off. Reconnect the wiring connector disconnected in Step 3. Disconnect and remove the timing light.
Disconnect the negative cable from the battery using the 5/16 inch wrench Wait 30 seconds and reconnect. This clears any fault codes stored by the computer.
