Abstract: An outwardly opening fuel injector comprises a valve needle movable within a bore provided in a nozzle body and engageable with a seating to control the supply of fuel from the bore. The valve needle is biased towards its seating and is moveable outwardly of the bore to move the valve needle away from its seating. The fuel injector comprises a sleeve member which is moveable with the valve needle, the valve needle and the sleeve member together defining a chamber for fuel such that, in use, fuel pressure within the chamber serves to dilate the sleeve member to reduce fuel leakage from the injector. A surface associated with the valve needle may be engageable with an additional seating defined by the bore to limit outward movement of the valve needle within the bore.