Engine phase determination and control

Abstract

In at least some implementations, a method of controlling spark events in an engine includes determining for at least two engine revolutions in a four-stroke engine at least one characteristic of the primary coil voltage for a spark event, determining, based upon the characteristic of the primary coil voltage, which of the spark events is associated with a compression phase and which of the spark events is associated with an exhaust phase of engine operation, and providing spark events in subsequent engine revolutions that are associated with the compression phase of engine operation but not in revolutions associated with the exhaust phase of engine operation. In at least some implementations, the characteristic is the duration of the spark event as determined by changes in the primary coil voltage, and the characteristic may be that the duration that the primary coil voltage is above a threshold voltage.

Dependencies are inferred from the claim text.