Spark ignition timing control system for internal combustion engine adapted to mixture fuel of more than one individual fuels having mutually different combustion characteristics

摘要

In order to accomplish aforementioned and other objects, a spark ignition timing control system, according to the present invention, is adapted to perform spark ignition timing control for an internal combustion engine combustioning a blended fuel, such as gasoline/alcohol mixture fuel. The control system performs MBT control by adjusting spark advance angle toward a maximum pressure point in feedback manner. The spark advance angle derived in MBT control is modified with a correction value derived on the combustion propagation speed which is variable depending upon blending ratio of one of the fuels in the blended fuel.