A fuel injector may include a housing, a pintle nozzle assembly and an actuation assembly. The housing may define a longitudinal bore, a high pressure fuel duct in communication with the longitudinal bore and a valve seat including a valve seat surface and an aperture. The pintle nozzle assembly may include a stem and a pintle and may be at least partially disposed within the longitudinal bore and be variably displaceable between a first position and a second position. In the first position, the pintle nozzle assembly may abut the valve seat to seal the aperture. In the second position, the pintle nozzle assembly may be displaced from the valve seat to open the aperture. The actuation assembly may be coupled with the pintle nozzle assembly and operate to move the pintle nozzle assembly to a plurality of positions between the first position and the second position.