A fuel injector assembly is provided which operates to effectively creating a low injection flow rate followed by a high injection flow rate during all engine operating conditions, including idle and low engine speed conditions, to produce a high quality fuel spray with proper atomization and thus improved fuel air mixing resulting in improved emissions abatement and fuel economy. The assembly includes two biased valve elements designed to sequentially open and close to initially open a limited number of orifices followed by the opening of a remainder of the orifices thereby effectively varying the available cross sectional flow area from the nozzle cavity into the combustion chamber of the engine during the injection event. The nozzle valve elements may be spring biased or fluid pressure biased and include biasing surfaces sized to cause the sequential opening and closing of the elements.