PURPOSE: To prevent a reduction in engine speed, by generating an idle-up command when an engine temperature is greater than a predetermined value at starting of an engine, and a predetermined condition permitting a secondary intake air to be supplied to the downstream of a throttle valve is not satisfied.
CONSTITUTION: During operation of an engine, when an operational condition of the engine satisfies a predetermined condition, a control circuit 20 controls a linear type solenoid valve 6 according to an output signal from an oxygen sensor 14 and supplies a secondary intake air into an intake pipe 4 downstream of a throttle valve 3. On the other hand, when an engine temperature detected by a water temperature sensor 12 is greater than a predetermined value at starting of the engine, and the above predetermined condition is not satisfied, an idle-up command is generated, thereby exciting a three-way solenoid valve 9 to communicate a vacuum supply passage 8 and open the throttle valve 3 through a throttle opener 7. Further, when an engine speed reaches a predetermined speed after the generation of the idle-up command, an idle-up stop command is generated.
SATO NAOHIKO
SUZUKI KATSUHIKO
TOTSUNE ATSUSHI
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