A fuel cell for use with a combustion tool for delivery of a predetermined amount of fuel with each stem actuation is provided and includes a housing defining an open end enclosed by a closure. A main valve stem has an outlet, disposed in operational relationship to the open end and reciprocating relative to the housing at least between a closed position wherein the stem is relatively extended, and an open position wherein the stem is relatively retracted. A fuel metering valve is located within the housing, associated with the main valve stem, including a fuel metering chamber disposed in close proximity to the closure and configured so that when the stem is in the open position, only a measured amount of fuel is dispensed through the outlet. In a preferred embodiment, the fuel cell housing includes a separate fuel container, and the fuel metering valve includes a valve body having a second end opposite the fuel metering chamber located within the container.