If the combustion status detected in a steady state is partial combustion, the setting of a combustion status control parameter for the next cycle is adjusted so as to provide an increased degree of partial combustion. If, on the other hand, the detected combustion status is fast combustion, the setting of the control parameter for the next cycle is adjusted so as to provide an increased degree of fast combustion. The combustion status can be detected in accordance with an output parameter that correlates with the engine torque.