Abstract: Apparatus for metering fuel and air for an engine, which apparatus comprises air flow measuring means which measures at least a part of the flow of air for the engine and which generates an electrical output that is proportional to the measured air flow, control means which receives the output from the air flow measuring means and which generates electrical output signals which vary in dependence upon the received signals, and an injector which injects fuel in response to the signals from the control means. Preferably the apparatus of the invention includes fuel dissipating means, such as a heat pipe or a sonic nozzle, for finely atomizing the injected fuel.