Fuel vapor handling system

A fueling control system for an internal combustion engine having a dual fluid fuel injection system, the fuelling controlling system including:

• a fuel supply means for supplying liquid fuel to at least one delivery injector of the dual fluid fuel injection system, and a gas supply means for supplying gas and fuel vapour to the at least one delivery injector, the fuel supply means including a fuel pump;
• a vapour control passage interconnecting the fuel supply means downstream of the fuel pump with the gas supply means to transfer fuel vapour from the fuel supply means to the gas supply means, wherein liquid fuel is delivered to the at least one delivery injector by the supply fuel means and fuel is delivered to the at least one delivery injector by the gas supply means;
• and
• a fuel level sensor means arranged to sense the level of fuel within the vapour control passage wherein the fuel pump is controlled as a function of the level of fuel within the vapour control passage.