| 摘要 |
PURPOSE:To improve follow-up performance of air-fuel ratio when loads change rapidly in a spark-ignition engine by estimating a throttle valve opening ratio when loads change rapidly and by reading out a basic injection pulse width from a map using the estimated value. CONSTITUTION:When engine revolutions learned from a revolution sensor 21 and throttle opening ratios are changing, a fuel feed control device 1 obtains change rates of the said quantities calculated in a CPU and a period of time from the time the information is read in to the time of an intake stroke. Using such results, opening ratios of the throttle valve 19 during the intake stroke are estimated, and using the estimates a basic injection pulse width is read out from a map stored in a ROM 8 and others to drive an injector 23 via a counter timer 4 and a driver 5. Thus, it is possible to maintain air-fuel ratios with good follow-up performance and high accuracy when loads change rapidly.
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