Abstract: An electronic control unit compulsorily stops supply of a fuel injection quantity, which is calculated based on various parameters including a throttle opening degree, performed by an injector in accordance with a crank angle signal if a series of operations, of rapidly opening a throttle valve from a certain throttle opening degree and then rapidly closing the throttle valve, occurs within a predetermined time in one combustion cycle of an internal combustion engine after completion of stroke determination. The electronic control unit removes the compulsory stoppage of the supply of the fuel injection quantity if drawing of an air intake quantity overlaps with at least one-third of an intake stroke in one combustion cycle of the engine.

Abstract: An ignition control system for an internal combustion engine includes a throttle opening detector, a crank angle detector, a stroke determiner, and an ignition timing corrector. The throttle opening detector detects a throttle opening of a throttle valve disposed in an intake passage of the internal combustion engine. The crank angle detector detects a crank angle signal associated with the rotation of a crankshaft of the internal combustion engine. The stroke determiner determines a stroke based on the crank angle signal. The ignition timing corrector corrects ignition timing in a retardation direction by a predetermined retardation angle when the throttle valve is rapidly opened to a predetermined throttle opening and then rapidly closed within a predetermined time period including one combustion cycle of the internal combustion engine. The stroke determiner defines the combustion cycle. The predetermined retardation angle is based on at least the throttle opening.

Abstract: An electronic control unit compulsorily stops supply of a fuel injection quantity, which is calculated based on various parameters including a throttle opening degree, performed by an injector in accordance with a crank angle signal if a series of operations, of rapidly opening a throttle valve from a certain throttle opening degree and then rapidly closing the throttle valve, occurs within a predetermined time in one combustion cycle of an internal combustion engine after completion of stroke determination. The electronic control unit removes the compulsory stoppage of the supply of the fuel injection quantity if drawing of an air intake quantity overlaps with at least one-third of an intake stroke in one combustion cycle of the engine.

Abstract: An ignition control system for an internal combustion engine includes a throttle opening detector, a crank angle detector, a stroke determiner, and an ignition timing corrector. The throttle opening detector detects a throttle opening of a throttle valve disposed in an intake passage of the internal combustion engine. The crank angle detector detects a crank angle signal associated with the rotation of a crankshaft of the internal combustion engine. The stroke determiner determines a stroke based on the crank angle signal. The ignition timing corrector corrects ignition timing in a retardation direction by a predetermined retardation angle when the throttle valve is rapidly opened to a predetermined throttle opening and then rapidly closed within a predetermined time period including one combustion cycle of the internal combustion engine. The stroke determiner defines the combustion cycle. The predetermined retardation angle is based on at least the throttle opening.