An engine assembly includes an intake manifold and a manifold absolute pressure sensor configured to generate a current measured manifold absolute pressure (MAP.sub.M) signal for the intake manifold. The assembly includes a throttle valve adjustable to control airflow to the intake manifold and a throttle position sensor configured to generate a current measured throttle position (TP.sub.M) signal. A controller is operatively connected to the throttle valve and the manifold absolute pressure sensor and has a processor and tangible, non-transitory memory on which is recorded instructions for executing a method for determining a predicted manifold absolute pressure (MAP.sub.P). Execution of the instructions by the processor causes the controller to determine the predicted manifold absolute pressure (MAP.sub.P) based at least partially on a predicted throttle flow (TF.sub.P) and the current measured manifold absolute pressure (MAP.sub.M) signal.

Methods and systems for operating an engine that includes an electrically operated throttle are disclosed. In one example, mitigating actions are taken in response to degradation of the electrically operated throttle so that the engine may be operated in a way that allows a driver to reach a service area.

In a control device of an internal combustion engine, an atmospheric pressure estimation portion includes an effective opening area calculation portion calculating an effective opening area corresponding to a throttle opening, a throttle opening learning value calculation portion calculating a learning value in a relation of the effective opening area and the throttle opening, an error variation calculation portion calculating an error variation from an error from the corrected learning value, a variation range determination portion determining whether the error variation is within a predetermined range, an atmospheric pressure estimated value update portion updating an atmospheric pressure estimated value, and a target throttle opening calculation portion calculating a target throttle opening using the updated atmospheric pressure estimated value. The throttle opening is controlled to be the target throttle opening. An exact atmospheric pressure can be thus estimated even in the presence of a variation in throttle machine difference.

A method for diagnosing a waste gate valve malfunction in a power generation system is presented. The method includes determining an actual pressure differential across a throttle valve. The method further includes determining an estimated pressure differential across the throttle valve based on one or more first operating parameters of the power generation system. Furthermore, the method includes determining an absolute difference between the actual pressure differential and the estimated pressure differential. Moreover, the method also includes comparing the absolute difference with a threshold value and if the absolute difference is greater than the threshold value, determining an operating condition of the throttle valve. Additionally, the method includes determining whether the waste gate valve has malfunctioned based on the determined operating condition of the throttle valve. An engine controller and a power generation system employing the method are also presented.

A control apparatus for an internal combustion engine comprises a throttle upstream pressure estimation unit which calculates, based on an AFS intake air amount from an AFS and an intake manifold pressure, an average density ave(n) in a region combining a supercharged portion from a downstream of a compressor to an upstream of a throttle valve and an intake manifold, and estimates a throttle upstream pressure based on the intake manifold pressure and the average density ave(n). Further, the throttle upstream pressure estimation unit learns a relationship between a throttle opening degree and an effective opening area to correct a throttle upstream pressure estimated value (estimated P2) based on a range of a throttle opening degree learning value, the throttle opening degree learning value, and a dispersion of the actual throttle opening degree error.

Methods and systems are provided for improving engine startability during cold-start conditions, when operating with gasoline fuels, alcohol fuels, or blended fuels. In one example, a method of engine cold-start control may include initiating fuel injection for cylinder combustion with manifold pressure lowered via intake throttle adjustments. The manifold pressure is lowered based on an optimization between cylinder charge reduction and improved fuel boiling at the lower pressure.

Methods and systems are provided for mitigating excessive exhaust pressures in an engine. In one example, a method may include adjusting an intake throttle responsive to exhaust pressure upstream of an exhaust turbine being higher than a threshold without reducing boost level. In this way, boost pressures may be maintained while reducing exhaust pressures.

An apparatus and a method for controlling intake surge noise of an engine of a vehicle are provided to suppress generation of noise due to an intake surge using an opening/closing location of a throttle valve and a time control when an intake surge pressure is generated. In particular, surge pressure and surge noise are removed by excluding an existing anti-surge valve or an existing intake purge valve, and determining whether intake surge generation conditions including a fuel supply state, intake pressures at front and rear ends of a throttle valve, a vehicle speed, and an engine speed to control an opening degree of the throttle valve for a predetermined time period.

A first control unit executes a valve stop inertial running including stopping an intake valve and an exhaust valve in a closed state during rotation of an output shaft, stopping supply of fuel to an engine, and setting a clutch in an engaged state to drive pistons of the engine by a rotational force from driving wheels. A second control unit executes a valve operation running including operating the intake valve and the exhaust valve during the rotation of the output shaft, and supplying the fuel to the engine based upon an intake conduit pressure. When a cancellation request is made during execution of the valve stop inertial running, a transient control unit operates the intake valve and the exhaust valve, and controls a throttle valve to an idling opening or less, thereby supplying a negative pressure to an intake passage.