Fuel Injector

A fuel injector for use in an injector arrangement including a pumping plunger (50), a pump chamber (52) and a spill valve arrangement (40) controlling communication between the pump chamber (52) and a low pressure fuel reservoir. The fuel injector comprises a valve needle (12) which is engageable with a seating to control fuel delivery through a fuel injector outlet opening, a first control chamber (25) being arranged such that the fuel pressure therein acts on a surface associated with the valve needle (12) and a second control chamber (44) being arranged such that fuel pressure therein acts on a surface associated with the spill valve arrangement (40). The injector further comprises a piezoelectric actuator arrangement including a piezoelectric element (32) having first and second ends, the first end being associated with the spill valve arrangement (40) and the second end being associated with the valve needle (12) such that, in use, operation of the spill valve arrangement (40) and movement of the valve needle (12) is controlled by controlling the energisation level of the piezoelectric element (32).