摘要 |
There are provided a control system and method and an engine control unit for an internal combustion engine, which are capable of attaining a high combustion efficiency in both of a homogenous and a stratified combustion modes, thereby improving drivability and fuel economy, as well as a control system for an internal combustion engine which is capable of ensuring stable combustion in both the modes. In one form of the invention, the control system includes an ECU for controlling ignition timing IG of an in-cylinder fuel injection type engine which is operated while switching the combustion mode between the homogeneous and stratified combustion modes. The ECU determines which of the homogeneous and stratified combustion modes should be selected. The ECU sets a first ignition timing for the homogenous combustion mode and a second ignition timing for the stratified combustion mode to respective values different from each other, and at the same time sets the first ignition timing for the homogeneous combustion mode such that the first ignition timing for the homogeneous combustion mode is more retarded as the detected engine temperature is higher. In another form of the invention, the ECU determines combustion parameters for the homogeneous and stratified combustion modes based on detected load on the engine. The ECU determines an ignition timing for the homogenous combustion mode based on the detected load, and an ignition timing for the stratified combustion mode based on the fuel injection termination timing for the stratified combustion mode.
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