The fuel delivery control system monitors engine speed and load parameters to develop a wall wetting history that is indicative of the physical state of the fuel within the intake port or intake manifold. The wall wetting history is used along with engine speed, temperature and pressure measurements to determine the pulse width of the fuel injector signal. Fuel to air ratio is thereby optimized. Transient conditions due to changes in engine load or due to acceleration and deceleration are used to generate a pulse width correction signal to optimize performance on a cycle by cycle basis. Each engine cylinder injector may be independently controlled.