the dynamic fuel control strategy all lean misfires were eliminated for tipin rates of 500 u00b0 sec or less as indicated by the imep trace an improvement of 0 5 1 0 in the average air fuel ratio during the decels was observed on the uego in a mass air system airflow is measured through a meter mounted upstream of the throttle body and cylinder air charge is inferred at the port using a manifold filling model of the form m tb air charge from throttle flow equ1 ncyl number of cylinders n engine speed rpm see fig8 and 9 for a graphical illustration of the operation of this invention fig8 illustrating throttle opening and fig9 illustrating throttle closing to reduce the effect of the delays mentioned in the problem statement of air fuel excursions a scheme to anticipate cylinder air charge two events in the future uses a recursion of the manifold filling model this anticipation scheme is effective in reducing the air fuel excursions during decelerations and light tipins however during fast throttle movement substantial change in air charge can occur over one induction event thus producing a series of very lean mixture events to improve the tipin transient response an algorithm was developed which allows fuel to be delivered on an open intake valve under conditions when lean misfire is likely this algorithm will be summarized.