Toyota Corolla 1970-1987 Repair Guide

Air Gap



See Figures 1 and 2

  1. Disconnect the negative battery cable.
  3. Unsnap the distributor cap retaining clips and lift the cap straight up. Leave the leads connected to the cap and position it out of the way. If it is necessary to disconnect any of the spark plug wiring leads ALWAYS tag them before removal.
  5. 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.
  7. Pull the ignition rotor (not the signal rotor) straight up and remove it. Replace it if the contacts are worn, burned or pitted. Do not file the contacts.
  9. 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.
  11. Obtain a non-ferrous (paper, brass, or plastic) feeler gauge of 0.012 in. (0.30mm), and insert it into the pick-up air gap. DO NOT USE AN ORDINARY METAL FEELER GAUGE! The gauge should just touch either side of the gap. The permissible range is 0.008-0.016 in. (0.20-0.40mm).

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Fig. Fig. 1: Checking the air gap on all engines except the 1983 and later A-series engines

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Fig. Fig. 2: Checking the air gap on 1983 and later 4A-C engine

The air gap on 283 and later 4A-C and most A-series engines is NOT adjustable. If the gap is not within specifications, the pick-up coil (igniter) must be replaced

  1. If the gap is either too wide or too narrow, loosen the Phillips screws (usually 2) mounting the pickup coil onto the distributor base plate. Then, wedge a screwdriver between the notch in the pickup coil assembly and the two dimples on the base plate, and turn the screwdriver back and forth until the pickup gap is correct.
  3. Tighten the screws and recheck gap, readjusting if necessary.
  5. After adjustment, install the distributor cap and connect the negative battery cable.