| 摘要 |
PURPOSE:To keep the catalytic action of a catalytic converter favourable, by providing a means for increasing the supplied quantity of fuel for a prescribed time from a predetermined point in time, and a clutch changeover means for putting an automatic transmission in neutral. CONSTITUTION:When an engine rotational frequency detection circuit 21 has found out that the rotational frequency of an engine has dropped below a set level near the idling level, the circuit generates an output signal to cause a timer 25 to start counting, to keep a transistor 12 on for a prescribed time. As a result, the supplied quantity of fuel is increased through a fuel passage 9 by a vacuum switch 11 and a thickening valve 10. At the same time, the output signal of an AND circuit 22 is applied to a clutch changeover solenoid 24 to shift a clutch into a neutral position. According to this constitution, the temperature of a catalytic converter is prevented from abnormally rising, so that the catalytic action of the converter is kept favourable. |
