Abstract: An engine control apparatus is provided with a control unit in which a fuel supply quantity Q.sub.f or a ignition timing .theta..sub.i is corrected to maximize an evaluation parameter A=P.sub.i /(Q.sub.a /N) obtained on the basis of a suction air quantity Q.sub.a, an engine speed N and a mean effective pressure P.sub.i in a engine, or to maximize a parameter B=P.sub.i /P.sub.b obtained on the basis of a suction pipe pressure P.sub.b and the mean effective pressure P.sub.i, or to maximize a maximum pressure P.sub.max or a mean effective pressure P.sub.i for every combustion cycle, so that control is performed on the basis of the result of the above correction. The control unit also performs feedback control of the fuel supply quantity Q.sub.f and corrects the ignition timing. Further, the control unit performs feedback control in a predetermined load-operation range of the engine, and stops the feedback control and corrects the fuel supply quantity Q.sub.

Abstract: An engine control apparatus is provided with a control unit in which a fuel supply quantity Q.sub.f or a ignition timing .theta..sub.i is corrected to maximize an evaluation parameter A=P.sub.i /(Q.sub.a /N) obtained on the basis of a suction air quantity Q.sub.a, an engine speed N and a mean effective pressure P.sub.i in a engine, or to maximize a parameter B=P.sub.i /P.sub.b obtained on the basis of a suction pipe pressure P.sub.b and the mean effective pressure P.sub.i, or to maximize a maximum pressure P.sub.max or a mean effective pressure P.sub.i for every combustion cycle, so that control is performed on the basis of the result of the above correction. The control unit also performs the feedback control of the fuel supply quantity Q.sub.f and corrects the ignition timing by the above-mentioned correction means. Further, the control unit performs feedback control in a predetermined load-operation range of the engine, and stops the feedback control and corrects the fuel supply quantity Q.sub.