Fuel injectior

A fuel injector comprising a nozzle body (10) defining a bore (11) within which an outer valve member (12) is slidable, the outer valve member (12) being engageable with a first seating (14) to control fuel injection from a first outlet opening (18) provided in a nozzle body (10). The outer valve member (12) is provided with a through bore (19) within which an inner valve member (20) is slidable, the inner valve member (20) being engageable with a second seating (26) to control fuel injection through a second outlet opening (28) provided in the nozzle body (10). The fuel injector further comprises first and second control chambers (56, 80) for fuel whereby, in use, movement of the inner and outer valve members (20, 12) away from their respective seatings (26, 14) is controlled by controlling fuel pressure within the first and second control chambers (56, 80) so as to permit fuel delivery from a selected outlet opening.