Compensation method and apparatus for fuel injection amount during engine warm-up

摘要

In a method and apparatus which compensates a fuel injection amount by a first fuel enrichment coefficient dependent on an engine coolant temperature during engine warm-up period after engine starting, the fuel injection amount is compensated further by a second fuel enrichment coefficient from a time an engine revolution speed falls until a time a predetermined interval lapses. The second fuel enrichment coefficient may be changed by a throttle valve opening condition and/or an engine intake air pressure. The fuel injection amount may be further compensated further by a third fuel enrichment coefficient until a time another predetermined interval shorter than the predetermined interval lapses, when a fall of the engine revolution speed is large.