Misfire prevention system during evaporated gas monitoring and control method thereof

摘要

The present invention relates to a misfire prevention system during evaporated gas monitoring and control method thereof by which an increased overall fuel quantity caused by the purge gas is considered and compensated thereto accordingly, so that occurrence of misfire resulted from changes of fuel-air ratio can be prevented. The system includes a fuel tank for storing fuel of a vehicle; a canister for temporarily collecting evaporated gas which is generated when the fuel stored in the fuel tank is evaporated; an engine for drawing up the evaporated gas collected in the canister by way of negative pressure and for burning the same with basic fuel to thereby operate a vehicle; a purge control valve being mounted between the engine and the canister to control pressure in the fuel tank; a shut-off valve being mounted at a discharge outlet of the canister to control the pressure in the fuel tank; a pressure sensor for detecting the pressure in the fuel tank; and an electronic control unit (ECU) for controlling operations of the purge control valve and the shut-off valve and for detecting leakage of the evaporated gas according to the pressure in the fuel tank detected by the pressure sensor and for compensating an increase of fuel quantity caused by purge gas during a racing to thereby maintain a fuel-air ratio at a constant level.