Abstract: Fuel delivery system for an internal combustion engine comprising a method and apparatus for generating and delivering a homogeneous charge with a variable fuel/air ratio which relies on fuel-absorbent, air-permeable evaporative wick membranes in a primary mixing region to which a portion of thermally-regulated air from an air dividing region has come. A single moving control element is used to control the quantity of in-rushing air in the primary mixing region, and therefore the amount of fuel rich air produced in this primary mixing region, and at the same time this single moving control element modulates both the quantity of fuel rich air and the quantity of regular fuel-free combustion air which are brought together in a secondary mixing region where they combine in the desired ratio to form a homogeneous charge with a variable fuel/air ratio. The use of a single moving control element allows extremely economical construction.