Fuel injector designed to optimize pattern of fuel spray

A fuel injector (18) for an internal combustion engine (11) which has a spray hole (25) designed geometrically to produce a spray of fuel so that substantially 70% or more of an amount of the spray hits a preselected area of a head (15) of an intake valve (150) of the engine when the intake valve (150) is closed. The preselected area is one of a first and a second area of the intake valve head (15) which are defined by a reference boundary line extending through a base end of a stem (26) of the intake valve (150). The preselected area is the first area closer to an intake manifold (17), while the second area is closer to an exhaust valve (160). This avoids rich misfire and reduces HC emissions from the engine (11) regardless of the intake valve (150) is in a closed state or in an open state.