| 摘要 |
<p>PURPOSE:To check variations in an air-fuel ratio, by delaying operation stoppage of a secondary air quantity detector, to be used for injection quantity control in time of driving when a secondary air flow control valve is controlled in a closing direction, as long as the specified time, in case of an engine provided with a secondary air passage branched off from a supercharging passage. CONSTITUTION:A supercharger 17, a surge tank 19, etc., are installed in supercharging passage 13 branched off from a main suction passage 12, while a secondary air passage 21, feeding an exhaust system with a part of supercharged air as secondary air, is branched off from the surge tank 19. In this secondary air passage 21, there are provided with a flow control valve 26 and a passage selector valve 27 interposingly. And, a fuel injection quantity is controlled by a control unit 40 according to the output made up of subtracting output of a secondary air detector 25 gtom that of a first air quantity detector 14. At this juncture, when the flow control valve 26 comes into such a driving state that feed of the secondary air is stopped or reduced in quantity, for the specified time from that point, detection of a secondary air quantity by the secondary air detector 25 is kept up, and afterward, the secondary air detection is controlled so as to be stopped.</p> |
