Abstract: The present invention provides an apparatus for controlling air flow within an internal combustion engine comprising a secondary air passage. The secondary air passage system includes an air inlet channel directing air flow to the air assist valve and an air outlet channel directing air flow from the air assist valve. The air outlet channel communicates with a plurality of fuel injector tips which are disposed within the engine. An air bypass circuit is interposed between the air inlet channel and the air outlet channel to provide an alternate air channel which is independent of the air assist valve. An engine controller electronically communicates with the air assist valve for causing the air assist valve to vary between its open and closed modes.

Abstract: According to the present invention, a system for controlling a runner system in an internal combustion engine is provided which optimizes the available torque output over a broad range of engine speeds. The system generally includes opening or closing a short runner bypass valve system according to changes in engine speed. More particularly, the method comprises sensing a speed of an engine, determining a current open/closed mode of a short runner bypass valve system, calculating a time to a short runner bypass valve system switch point, including compensating for a time period required to switch between open and closed modes, and switching the short runner bypass valve open/closed mode at a given time if the current open/closed mode is not equal to a desired mode.

Abstract: A system and method of monitoring the purge flow in an evaporative emission control purge system of a motor vehicle. Signals indicative of engine speed, fuel control and automatic idle speed position are measured and used to determine whether the purge flow system is operating properly. With purge flow activated, the amount of purge flow is increased in accordance with a ramping rate and the measured signals are monitored to determine whether or not a change occurs in any one of the engine speed, fuel control and AIS position signals.

Abstract: A method of throttle fuel lean-out for an internal combustion engine including the steps of sensing a throttle position of a throttle for the engine with a throttle position sensor, calculating a delta throttle value based on the sensed throttle position, determining whether the engine is in a throttle deceleration condition based on the calculated delta throttle value, linearizing the change in throttle position with respect to absolute throttle position and engine speed if the engine is in a throttle deceleration condition, calculating a throttle deceleration fuel lean-out multiplier value based on the linearized change in throttle position, and applying the calculated throttle deceleration fuel lean-out multiplier value to a fuel pulsewidth value of fuel injectors for the engine and reducing the amount of fuel injected into the engine by the fuel injectors.

Abstract: A method is provided for controlling knock on an internal combustion engine. The method includes the steps of determining a maximum value of knock and determining whether conditions are right for updating the maximum value of knock. The method also includes using an unmodified spark advance if conditions are not right for updating the maximum value of knock and modifying the spark advance if conditions are right for updating the maximum value of knock.

Abstract: A method of controlling an intake manifold tuning valve (MTV) for an internal combustion engine includes the steps of sensing the position of the throttle, determining whether the throttle position is greater than or equal to wide open throttle (WOT), and opening the intake MTV if the throttle position is not greater than or equal to WOT. The method also includes the steps of sensing the speed of the engine if the throttle position is greater than or equal to WOT, determining whether the engine speed is outside a first and second predetermined speeds, closing the intake MTV if the engine speed is outside the range between first and second predetermined speeds and opening the intake MTV if the engine speed is not outside the range between first and second predetermined speeds.