| 摘要 |
PURPOSE:To control an engine to the optimum ignition timing without causing the inflence due to an external factor, by performing prescribed arithmetic operation so as to obtain an engine speed in the increasing direction from combination of plurally set ignition timings and correcting the combination of the ignition timings. CONSTITUTION:In an ignition control circuit 26 controlling the operation of an ignition device 20, firstly the target ignition timing is calculated from outputs of an intake air amount sensor 16 and speed sensor 18. Then combination of ignition timings having a prescribed value for each cylinder in the vicinity of the target ignition timing is plurally selected to perform both operations for a prescribed period with enach of the combination and two times the operations in at least one ignition timing combination of said operations. Then from change of an operational condition at this operation, an operational condition signal in the other combination is corrected. And in accordance with a level of value showing a condition of deviation unevenness of the operational condition signal only by a combination difference between each ignition timing, whether the operational condition is in an optimum state or not is decided to control the ignition timing combination. |
