| 摘要 |
PURPOSE:To prevent an engine speed from decreasing, by setting the lower limit of opening of a control valve to a value calculated on the basis of a study value and the running condition of an automobile during feedback control of the idle speed control valve. CONSTITUTION:An electronic control device 31, performing feedback control by the control routine of an idle speed control (ISC) valve, decides an engine for whether or not it is in a hot idle period. If it is in the hot idle period, duty ratio D is limited to a value above the lower limit Dmina in the hot idle period. Then a study value Dg is updated. If not in the hot idle period, the duty ratio D is limited so as to become a value above the lower limit Dminb by calculating the lower limit Dminb of the duty ratio D in a non-hot idle period on the basis of the study value Dg. In such way, a speed of the engine immediately before completion of its deceleration can be prevented from decreasing. |
