| 摘要 |
PURPOSE:To prevent the unstable control of ignition timing and improve the drivability, by stopping a feedback control of ignition timing when a maximum timing of a cylinder pressure is within a predetermined range. CONSTITUTION:In a control unit 100, a cylinder pressure as an output from an amplifier 4 is A/D converted by an A/D converter 104, which is repeated until a predetermined angle, and each value is stored. The maximum of the values stored is found, and the corresponding crank angle as detected is regarded as a maximum timing of the cylinder pressure. Then, a target range slice level of the maximum timing of the cylinder pressure according to an engine speed and a suction air quantity per rotation to be calculated according to signals from a crank angle sensor 2 and an air flow meter 3 is obtained from a table stored in ROM 102. If the maximum timing of the cylinder pressure is outside the target range, an ignition timing is feedback controlled to be retarded or advanced, while if the maximum timing is within the target range, the feedback control is stopped. |
