Abstract: Methods and systems are provided for tracking a fuel puddle mass in the intake port of a deactivated engine cylinder. The difference in fuel evaporation rate in the deactivated cylinder intake is accounted for by applying distinct time constant and gain values to a transient fuel compensation model. A fuel vapor content is clipped once the intake vapor pressure in the intake port of the deactivated cylinder reaches a saturation pressure limit.

Abstract: Methods and systems are provided for tracking a fuel puddle mass in the intake port of a deactivated engine cylinder. The difference in fuel evaporation rate in the deactivated cylinder intake is accounted for by applying distinct time constant and gain values to a transient fuel compensation model. A fuel vapor content is clipped once the intake vapor pressure in the intake port of the deactivated cylinder reaches a saturation pressure limit.

Abstract: Methods and systems are provided for tracking a fuel puddle mass in the intake port of a deactivated engine cylinder. The difference in fuel evaporation rate in the deactivated cylinder intake is accounted for by applying distinct time constant and gain values to a transient fuel compensation model. A fuel vapor content is clipped once the intake vapor pressure in the intake port of the deactivated cylinder reaches a saturation pressure limit.

Abstract: Methods and systems are provided for tracking a fuel puddle mass in the intake port of a deactivated engine cylinder. The difference in fuel evaporation rate in the deactivated cylinder intake is accounted for by applying distinct time constant and gain values to a transient fuel compensation model. A fuel vapor content is clipped once the intake vapor pressure in the intake port of the deactivated cylinder reaches a saturation pressure limit.

Abstract: A method for starting an internal combustion engine having direct fuel injection, comprising of adjusting a number of direct injections per combustion cycle based on a cylinder event number from a first cylinder event.

Abstract: A method for starting an internal combustion engine having direct fuel injection, comprising of adjusting a number of direct injections per combustion cycle based on a cylinder event number from a first cylinder event.

Abstract: A method for starting an internal combustion engine having direct fuel injection, comprising of adjusting a number of direct injections per combustion cycle based on a cylinder event number from a first cylinder event.

Abstract: A method for starting an internal combustion engine having direct fuel injection, comprising of adjusting a number of direct injections per combustion cycle based on a cylinder event number from a first cylinder event.

Abstract: A method for starting an internal combustion engine having direct fuel injection, comprising of adjusting a number of direct injections per combustion cycle based on a cylinder event number from a first cylinder event.

Abstract: A method for starting an internal combustion engine having direct fuel injection into a cylinder, comprising of only for a first combustion event under selected conditions during an engine start, directly injecting fuel to the cylinder at least twice, where each of said two injections at least partially occur during a compression stroke.

Abstract: A method for starting an internal combustion engine having direct fuel injection, comprising of adjusting a number of direct injections per combustion cycle based on a cylinder event number from a first cylinder event.

Abstract: A method for starting an internal combustion engine having direct fuel injection, comprising of adjusting a number of direct injections per combustion cycle based on a cylinder event number from a first cylinder event.

Abstract: An emissions control system for a vehicle configured to travel on a road is provided. In one example, a forced modulation of a UEGO is provided when output of a HEGO sensor is unavailable.

Abstract: A method for starting an internal combustion engine having direct fuel injection, comprising of adjusting a number of direct injections per combustion cycle based on a cylinder event number from a first cylinder event.

Abstract: A method for starting an internal combustion engine having direct fuel injection, comprising of adjusting a number of direct injections per combustion cycle based on a cylinder event number from a first cylinder event.

Abstract: A method for starting an internal combustion engine having direct fuel injection, comprising of adjusting a number of direct injections per combustion cycle based on a cylinder event number from a first cylinder event.

Abstract: A method for starting an internal combustion engine having direct fuel injection into a cylinder, comprising of only for a first combustion event under selected conditions during an engine start, directly injecting fuel to the cylinder at least twice, where each of said two injections at least partially occur during a compression stroke.

Abstract: An emissions control system for a vehicle configured to travel on a road is provided. The system typically includes a catalyst coupled to the exhaust gas path, a linear universal exhaust gas oxygen (UEGO) sensor coupled to the exhaust gas path upstream of the catalyst and configured to measure oxygen content in exhaust gas from the engine upstream of the catalyst, and a heated exhaust gas oxygen (HEGO) sensor positioned adjacent the catalyst and configured to measure oxygen content in exhaust gas from the engine. The system further typically includes a controller coupled to the engine and configured to, during a warm up period of the catalyst during which input from the HEGO sensor is unavailable, adjust an engine air-fuel ratio of the engine in response to the input from the linear exhaust gas oxygen sensor, and further configured to provide modulation of said air-fuel ratio during the warm up period so that the air-fuel ratio of the engine oscillates about a selected target ratio.

Abstract: An emissions control system for a vehicle configured to travel on a road is provided. The system typically includes a catalyst coupled to the exhaust gas path; a linear universal exhaust gas oxygen (UEGO) sensor coupled to the exhaust gas path upstream of the catalyst and configured to measure oxygen content in exhaust gas from the engine upstream of the catalyst; a heated exhaust gas oxygen (HEGO) sensor positioned adjacent the catalyst and configured to measure oxygen content in exhaust gas from the engine; a temperature sensor coupled to the engine; and a controller coupled to the engine and configured to receive an input signal from the HEGO sensor that is indicative of oxygen content in the exhaust gas, to receive an input signal from the temperature sensor that is indicative of engine temperature, to adjust the HEGO sensor input signal based on the input signal from the temperature sensor, and to control the air-fuel ratio based on the adjusted HEGO sensor input during engine warm up.