The air gap is NOT adjustable. If the gap is not within specifications, the distributor must be replaced.
- Remove the distributor cap. Inspect the cap for cracks, carbon tracks or a worn center contact. Replace it if necessary, transferring the wires one at a time from the old cap to the new one.
- Pull the ignition rotor (not the signal rotor) straight up and remove it. Replace it if the contact is worn, burned or pitted. Do not file the contacts.
- Turn the engine over (you may use a socket wrench on the front pulley bolt to do this) until the projection on the pickup coil is directly opposite the signal rotor tooth.
- Use only a non-ferrous (paper, brass, or plastic) feeler gauge set. This means that they are non-magnetic; if you have any doubt, check the feeler with a magnet. If the magnet sticks, don't use that feeler gauge.
- Select a non-ferrous feeler blade of 0.02 in. (0.30mm) thickness, and insert it into the pick-up air gap. The gauge should just touch either side of the gap. The permissible range is 0.008-0.016 in. (0.20-0.40mm) except for 1989-90 Land Cruisers. These vehicles require only that the gap be greater than 0.001 in. (0.2mm).