Abstract: An electronic throttle control unit includes an air bypass channel having a removable obstruction that opens in response to receiving an electronic throttle control fault signal and thereby allowing the vehicle a limp home condition. The throttle plate defaults to a fully closed position upon engine-off to substantially prevent evaporation and escape of hydrocarbons from the intake manifold to the atmosphere.

Abstract: Unwanted high frequency sound caused by air passing over a pore in the air passageway of an IACV casting is reduced or eliminated by creating a stepped diameter adjacent the pore in the air passageway.

Abstract: A speed control apparatus for an internal combustion engine including a poppet valve seat and a poppet valve pintle assembly disposed coaxially for variably regulating the flow of air into the engine across the valve seat. The pintle is axially positioned by a stepper motor actuator responsive to an engine speed sensor and electronic controller. The controller varies the axial position of the pintle in accordance with a programmed algorithm to provide any desired engine speed, and especially a fixed engine speed, under a range of engine loads. The invention eliminates the need for a governor, rotary mechanical throttle, and cable or mechanical linkages, and is especially useful for small engine applications such as in powering a portable electric generator, yard equipment, or outboard motor.