Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, a position of an engine air intake throttle is adjusted during cylinder deactivation to control intake manifold pressure for cylinder reactivation. Closing of the throttle may be timed based on an actual total number of cylinder induction events expected to provide a desired engine intake manifold pressure.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, a position of an engine air intake throttle is adjusted during cylinder deactivation to control intake manifold pressure for cylinder reactivation. Closing of the throttle may be timed based on an actual total number of cylinder induction events expected to provide a desired engine intake manifold pressure.

This disclosure is intended to suppress a noble metal supported by a three-way catalyst from being deteriorated by oxidation with the execution of fuel cut processing in a suitable manner. A control apparatus for a naturally aspirated gasoline engine is provided with a three-way catalyst, a first throttle valve, a second throttle valve arranged in the intake passage at the downstream side of the first throttle valve, an EGR valve, and a controller. When the controller carries out fuel cut processing and the temperature of the three-way catalyst is equal to or higher than a predetermined temperature, the controller introduces the EGR gas into a cylinder of the gasoline engine as intake air by fully closing the first throttle valve and by opening the EGR valve, and further controls an amount of the EGR gas by adjusting the degree of opening of the second throttle valve.

This disclosure is intended to suppress a noble metal supported by a three-way catalyst from being deteriorated by oxidation with the execution of fuel cut processing in a suitable manner. A control apparatus for a naturally aspirated gasoline engine is provided with a three-way catalyst, a first throttle valve, a second throttle valve arranged in the intake passage at the downstream side of the first throttle valve, an EGR valve, and a controller. When the controller carries out fuel cut processing and the temperature of the three-way catalyst is equal to or higher than a predetermined temperature, the controller introduces the EGR gas into a cylinder of the gasoline engine as intake air by fully closing the first throttle valve and by opening the EGR valve, and further controls an amount of the EGR gas by adjusting the degree of opening of the second throttle valve.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, valves of a cylinder are deactivated in a closed state in response to an indication of degradation of a valve of the cylinder. Further, fuel flow to the cylinder may be stopped via ceasing to inject fuel to the cylinder.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, valves of a cylinder are deactivated in a closed state in response to an indication of degradation of a valve of the cylinder. Further, fuel flow to the cylinder may be stopped via ceasing to inject fuel to the cylinder.

Systems and methods for detecting and controlling knock in an engine are presented. In one example, engine knock sensors are selected based on whether or not certain cylinders are activated and combusting air and fuel or deactivated and not combusting air and fuel. Output of selected knock sensors is the basis for adjusting engine spark timing.

Systems and methods for detecting and controlling knock in an engine are presented. In one example, engine knock sensors are selected based on whether or not certain cylinders are activated and combusting air and fuel or deactivated and not combusting air and fuel. Output of selected knock sensors is the basis for adjusting engine spark timing.

Methods and systems are provided for the integration of a fuel level sensor and a fuel pressure sensor in a fuel tank within a fuel system. In one example, an integrated fuel pressure and fuel level sensor for a fuel tank may include a float arm of the fuel sensor coupled to a floating body and a pressure sensor (e.g., a fuel tank pressure transducer) coupled to the floating body, the integrated fuel pressure and fuel level sensor adapted to simultaneously measure fuel level and fuel vapor pressure of the fuel tank.

Methods and systems are provided for the integration of a fuel level sensor and a fuel pressure sensor in a fuel tank within a fuel system. In one example, an integrated fuel pressure and fuel level sensor for a fuel tank may include a float arm of the fuel sensor coupled to a floating body and a pressure sensor (e.g., a fuel tank pressure transducer) coupled to the floating body, the integrated fuel pressure and fuel level sensor adapted to simultaneously measure fuel level and fuel vapor pressure of the fuel tank.