Method and system for pre-ignition control

摘要

Methods and systems are provided for reducing late burn induced cylinder pre-ignition events. Forced entry of residuals from a late burning cylinder into a neighboring cylinder may be detected based on engine block vibrations sensed in a window during an open exhaust valve of the late burning cylinder. In response to the entry of residuals, a pre-ignition mitigating action, such as fuel enrichment or deactivation, is performed in the neighboring cylinder.

主权项

1. An engine method comprising:
delaying combustion timing in a first cylinder; sensing engine block vibrations in a first window during an open exhaust valve of the first cylinder; and performing a pre-ignition mitigating action in a second cylinder based on an amplitude of the sensed engine block vibrations at a first frequency range in the first window being higher than a first threshold.