Knock Sensor

The knock sensor consists of a piezoelectric crystal encased in a metal and plastic housing. Vibrations in the engine cause the crystal to generate small amounts of voltage. This voltage signal is used by the ICU to determine necessary timing retardation.

If knocking is detected, the ICU will retard the ignition 3.4 degrees. If the knocking stops, timing will advance in steps of .54 degrees until it reaches the pre-programmed value. If knocking continues, timing can be retarded as much as 12 degrees.

The knock sensor is located on the left side of the cylinder block, next to cylinder No. 3. The knock sensor connector is located on a bracket next to the distributor.