PURPOSE: To keep off any richness in an air-fuel ratio due to a percolation phenomenon as well as to improve the startability of an engine, by controlling the flow regulating valve installed in a suction secondary air feeding passage to the control opening conformed to engine temperature at time of engine's hot restarting.
CONSTITUTION: When an engine 5 is driven, a control circuit 20 controls a linear type solenoid valve (flow regulating valve) 9 installed in a suction secondary air feeding passage 8 to be interconnected to the inside of a suction pipe at the downstream of a throttle valve 3 and it also controls an air-fuel ratio of mixture on the basis of various engine running parameters. In this case, at the control circuit 20, the solenoid valve 9 is opened as much as the control opening conformed to engine temperature when this engine temperature is higher than hot discriminating temperature by a water temperature sensor 12, and car speed V by a car speed sensor 16 is lower than low car seed discriminating temperature, while engine speed by a crank angle sensor 11 is smaller than cranking speed. With this constitution, a proper amount of secondary air feeding is carried out, thus the air-fuel ratio is prevented from richness.
SHIMAMURA HARUO
SUZUKI KOZO
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