Fuel injection apparatus comprising a solenoid coil (40); an armature (41) coupled with a valve element (34) operable to open and close a fuel valve (32) when the solenoid coil (40) is selectively energized and de-energised. The valve element (34) is biased to the closed position by a biasing device (42). Magnetic force from the energized solenoid coil moves the armature (41) and valve element (34) to open the valve to an opening position to deliver fuel reached when a controller (170) calculates opening forces balance closing forces. Such opening position control is used to control fuel flow rate to a gas fuelled engine (20) and/or reduce noise vibration harshness in varied engine types. Balance of forces control, on closing of the valve, reduces or avoids impact of the valve element (34) with a physical stop (106), thus reducing engine noise, and can be used in fuel metering.