How to Use the Actron Timing Light

by Dan Ferrell
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Your Actron timing light allows you to synchronize your car's spark to base timing for better engine operation. If the ignition timing is too advanced, the engine's cylinders will operate under abnormal combustion, causing knocks or pings. If ignition timing is too retarded, you will notice an increase in fuel consumption or lack of engine power. In severe cases, retarded timing can cause engine overheating and damage. Adjust the base timing in your vehicle yourself to save on fuel and expensive repairs down the road.

Step 1

Warm up the engine by idling it for about 20 minutes and then turn it off.

Step 2

Locate the timing marks on the crankshaft pulley, which is located at the front and bottom of the engine. Above this pulley, you will see a small plate with numbers indicating timing degrees. On the pulley, you will find a groove mark, which is used to indicate engine base timing using your Actron light. Wipe clean these marks with a shop rag and trace the marks with a white marker or chalk for better visibility.

Step 3

Remove the ignition key from the ignition lock to make sure the switch is in the Off position.

Step 4

Disconnect the vacuum line from the distributor (if your car is so equipped) and plug this line with a small Phillips screwdriver. Alternatively, disconnect the plastic cap from the wire connector next to the distributor. The distributor is the component where the spark plug wires connect.

Step 5

Get your Actron light out of your toolbox and hook the light clamp to the spark plug wire on cylinder number one, as close to the spark plug as possible. If you stand in front of the engine, facing the drive belt, the cylinder closest to the front end of the engine is number one.

Step 6

Connect the black cable clip on the light to the terminal on the ground (black) battery cable and the red cable clip on the light to the terminal on the positive (red) battery cable.

Step 7

Start and idle the engine. Push the button on the back of your timing light with your thumb and aim the light at the crankshaft pulley. Check that the mark on the pulley points to the correct number on the degree scale, according to the timing information in the Emissions Control label on the engine compartment or your car owner's manual.

Step 8

Adjust the timing, if necessary, by loosening the distributor hold-down bolt with a wrench. Rotate the distributor slowly left or right, to bring the mark on the crankshaft pulley to the correct degree number on the scale. Tighten the distributor hold-down bolt with the wrench and double check that the mark is still pointing to the correct number.

Step 9

Turn off the engine, disconnect your Actron timing light and reconnect the vacuum line to the distributor or the cap to the wire connector next to the distributor.

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