| 摘要 |
PURPOSE:To prevent minute variation of an idle rotational speed of an engine in controlling the idle rotational speed within a predetermined range by a feedback control by correctively controlling the ignition period, or the ignition timing on the basis of the variation of the rotational speed of the engine, within the above range. CONSTITUTION:While an engine is running, the differnece (variation rate TP of the present basic injection quantity TP and the previous basic ignition quantity LTP calculated in the process of controlling the injection quantity is obtained by a variation rate calculating means 3 provided in a control circuit. An actual idle rotational speed N is checked if it is within a predetermined range by an idling stability detective means 2, and when it is judged YES, the idling is considered to be stable and firstly the feedback correction value is clamped to the value as theretofore and the feedback control for the idle rotational speed is stopped. A corrective value C for the ignition advance angle is searched for by an ignition timing corrective means 4 based on the variation rate DELTATP and the ignition advance angle is corrected by the corrective value C to control an ignitor 5. |
