Fuel control apparatus

Claim 1

A fuel control-apparatus which comprises a fuel supplying means for supplying fuel to an internal combustion engine in response to the operation of a fuel control valve, an intake air quantity sensor disposed in an air intake passage of said internal combustion engine to detect a quantity of intake air, an air-fuel ratio sensor attached to the exhaust pipe of said engine to produce an output in response to an air-fuel ratio and a fuel control means which receives the output of said intake air quantity sensor to calculate a basic value corresponding to an amount of fuel required for said engine, and corrects said basic value by a negative feed-back control on the basis of the output of said air-fuel ratio sensor so as to obtain a desired air-fuel ratio to thereby supply the fuel to said engine by controlling said fuel control valve, wherein said fuel control means comprises a writing means for writing in a memory a value of negative feed-back correction or a value related thereto when the output of said intake air quantity sensor is in the vicinity of a representative point, a correcting means for correcting said basic value on the basis of data in said memory and a valve controlling means to close a control valve which controls feeding of vaporized fuel caught in a canister to the air intake system of said engine when said value of negative feed-back correction or the value related thereto is written in said memory.