Abstract: An apparatus and method for adjusting a quantity of fuel delivered to an engine when an engine operating state transitions is provided. The apparatus and method includes determining a current steady-state quantity of fuel to be delivered to the engine and add a transitory quantity of fuel, based on a difference between a previous steady-state quantity of fuel delivered and the current steady-state quantity of fuel to be delivered, to the current steady-state quantity of fuel for a period of time following initiation of the transition. The invention also provides an apparatus and method by which an operator may adjust the amount of fuel delivered during an engine operating state transition.