ignition timing

Light To prepare for the adjustment, ensure that all other systems on your vehicle (airflow, fuel pressure, idle rpm, etc.) are operating properly. Though not necessary to set ignition timing, this would be an ideal point to replace your spark plug wires, distributor cap, rotor and spark plugs. Connect the timing light (and tachometer, if used) to your vehicle's battery and No. 1 spark plug wire per the manufacturer's instructions. Check the vehicle specifications to determine the proper timing advance (often noted on a sticker on the underside of the hood), read in "degrees before top dead center" at a particular rpm. In this case the recommended advance is five degrees at a 750-rpm idle. Being very careful to avoid entanglement with moving belts and pulleys, start the engine and bring to normal operating temperature and specified rpm. Direct the timing light to the main crank pulley, and observe where the timing mark on the pulley falls compared to the degree tab on the front of the engine. If the marks line up properly, the ignition timing is correct and no adjustment is necessary. If not, your engine's power and mileage have likely suffered and adjustment is required.