You searched for: “preignition
preignition, pre-ignition
1. The ignition of the fuel mixture in a gasoline engine cylinder before normal ignition by the spark plug, typically caused by overheated plug points.

This results in an inefficient, rough-running engine.

2. Ignition of fuel in an internal-combustion engine before the spark has been generated, causing inefficient operation.

Preignition may be caused by a hot spot in the cylinder.

This entry is located in the following unit: ign-, igni-, ignis- + (page 3)