Abstract: Methods and systems are provided for pressure control in a boosted engine system. A variable geometry turbine (VGT) geometry, and/or wastegate (WG), and/or an exhaust gas recirculation (EGR) valve opening is adjusted at least based on a difference between the exhaust pressure and an intake pressure in order to reduce the difference between exhaust and intake manifold pressures, thereby reducing pumping work losses.

Abstract: Methods and systems for evaluating cylinder pressure profiles in cylinders of an engine are disclosed. In one example, fuel injection timing of engine cylinders is adjusted to improve engine combustion in response to output of one or more pressure sensors installed in engine cylinders. Combustion within a plurality of engine cylinders may be adjusted in response to pressure sensed in a single engine cylinder.

Abstract: Methods and systems are provided for pressure control in a boosted engine system. A variable geometry turbine (VGT) geometry, and/or wastegate (WG), and/or an exhaust gas recirculation (EGR) valve opening is adjusted based a difference between the exhaust pressure and an intake pressure, and optionally other signals (e.g., engine speed, exhaust pressure) in order to reduce the difference between exhaust and intake manifold pressures, thereby reducing pumping work losses.

Abstract: Methods for controlling a glow plug temperature in a diesel engine are herein described. In one example, a controller may adjust a first phase voltage coupled to the glow plug in relation to a parameter associated with engine start time, and couple a lower second phase voltage to the glow plug in order to control the cylinder temperature and thereby the engine start time. In one particular example, the reduced second phase voltage allows the operating cycle push phase to be extended, which increases glow plug durability and further allows for the useful life of the glow plug to be extended.

Abstract: A method for operating a turbocharged engine is disclosed. In one example, during a first condition an engine operation is adjusted in response to a turbocharger expansion ratio exceeding a first limit and during a second condition an engine operation is adjusted in response to the turbocharger expansion ratio exceeding a second limit that differs from the first limit. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: Various methods and systems are provided for adjusting a pilot injection during initial engine operation from vehicle manufacture. In one example, a method comprises delivering a first proportion of fuel as the pilot injection, and only decreasing the first proportion of fuel responsive to learning an injector flow characteristic.

Abstract: Methods and systems for evaluating cylinder pressure profiles in cylinders of an engine are disclosed. In one example, fuel injection timing of engine cylinders is adjusted to improve engine combustion in response to output of one or more pressure sensors installed in engine cylinders. Combustion within a plurality of engine cylinders may be adjusted in response to pressure sensed in a single engine cylinder.

Abstract: Methods and systems are provided for detecting hydrocarbon ingestion into an engine based on the simultaneous monitoring of cylinder imbalance and an elevated exhaust exotherm. Crankshaft acceleration data is monitored during steady-state and transient engine conditions while exhaust temperatures are estimated during non-regeneration conditions. Engine speed and load is limited to reduce further hydrocarbon ingestion.

Abstract: Methods and systems are provided for reducing turbo lag in a boosted engine. A boost reservoir coupled to the engine may be charged with compressed intake air and/or combusted exhaust gas. The pressurized charge may then be discharged during a tip-in to either the intake or the exhaust manifold.

Abstract: A method for an engine may comprise, in response to an EGR valve closing, determining an EGR oxygen content, and purging an EGR system when the EGR oxygen content is less than a threshold oxygen content.

Abstract: A method for operating a vehicle system is described herein. The method includes indicating a variable geometry turbine degradation based on a comparison of a modeled set of turbine pressure values and a sensed set of turbine pressure values, each set of turbine pressure values including a pressure value upstream of the turbine and a pressure value downstream of the turbine and the variable geometry turbine positioned downstream of an engine cylinder.

Abstract: A method for diagnosing a performance issue in a vehicle system having a diesel engine, a fuel system, and an on-board diagnostic system. The method includes cranking the engine, and, if a pressure sensed in the fuel system during or after the engine cranking differs by a threshold amount from the pressure sensed during a previous operation of the engine, indicating excessive fuel viscosity in the on-board diagnostic system.

Abstract: Methods and systems for monitoring an internal combustion engine are disclosed. In one example, output of a temperature sensor is converted into a fuel pressure variable to determine if fuel system components are operating as desired and cylinder air charge may be limited if degradation is determined. The methods and systems may reduce fuel system cost while also providing redundant system data.

Abstract: Various methods and systems are provided for adjusting a pilot injection during initial engine operation from vehicle manufacture. In one example, a method comprises delivering a first proportion of fuel as the pilot injection, and only decreasing the first proportion of fuel responsive to learning an injector flow characteristic.

Abstract: Embodiments for controlling condensate in an engine heat exchanger are disclosed. In one example, a method for an engine comprises increasing exhaust gas recirculation (EGR) flow responsive to condensation in an EGR cooler. In this way, condensate in the EGR cooler may be controlled via modulation of EGR flow.

Abstract: Embodiments for controlling cylinder air flow are provided. In one example, a method for controlling airflow into a cylinder of an engine comprises, if a previous cylinder airflow is different than a desired cylinder airflow, allocating flow into an intake manifold between a throttle and an EGR valve to provide the desired cylinder airflow while maintaining a desired EGR amount in the cylinder. In this way, transient air flow requests may be met without delay while maintaining desired cylinder EGR amounts.

Abstract: Methods and systems are provided for draining water separated from diesel fuel into an EGR system. In response to the water volume in the fuel system and EGR flow at pre-determined levels, water may be introduced into the EGR system. EGR flow may also be controlled in response to introducing water into the EGR system and engine operating conditions.

Abstract: A method for operating a vehicle system is described herein. The method includes indicating a variable geometry turbine degradation based on a comparison of a modeled set of turbine pressure values and a sensed set of turbine pressure values, each set of turbine pressure values including a pressure value upstream of the turbine and a pressure value downstream of the turbine and the variable geometry turbine positioned downstream of an engine cylinder.

Abstract: A method for an engine may comprise, in response to an EGR valve closing, determining an EGR oxygen content, and purging an EGR system when the EGR oxygen content is less than a threshold oxygen content.

Abstract: A fuel system for an engine is provided herein. According to one embodiment, the fuel system includes a fuel supply coupled to a low pressure fuel pump, the low pressure fuel pump coupled to a high pressure fuel pump to provide fuel to a fuel rail. Further, the fuel system includes a plurality of injectors coupled to the fuel rail to provide fuel to a plurality of engine cylinders. Further still, the fuel system includes a first fuel return line coupling the fuel rail to the fuel supply and a thermal recirculation valve, the thermal recirculation valve further coupled to a low pressure pump intake line; a second fuel return line coupling the high pressure fuel pump to the first fuel return line; and a third fuel return line coupling the plurality of injectors to a high pressure pump intake line.