PURPOSE: To properly take a measure to counter acceleration shock also considering the operating condition of an engine before accelerating by stopping an accelerating-time ignition timing control or reducing a correcting quantity at the time of accelerating from a medium or high load zones.

CONSTITUTION: In a control unit 20, as the start of acceleration is detected based on the opening of a throttle valve 7 detected by a throttle sensor 8, ignition timing is corrected to a delay side until a defined time elapsed form the start of the acceleration under the control of a time measuring means, thereby, making the rise in torque relatively gentle to prevent an acceleration shock. Here, if the last-time value of a fundamental fuel injection quantity is above a defined value while the load before starting acceleration is above a defined value, i.e., at the time acceleration from medium or high load zones, the correcting quantity by the accelerating-time ignition timing control is reduced or the correction is stopped. Thereby, a sufficient acceleration feeling can be obtained at the time of acceleration from the medium and high load zones in which an acceleration shock is insignificant, improving accelerating performance.