An engine control system for an auto-stop/start vehicle includes an auto-stop/start module that generates an auto-stop command for shutting down an engine while an ignition is ON and subsequently generates an auto-start command for re-starting the engine. The system includes an actuator control module that disables an engine load, parks exhaust and intake cam phasers, disables fuel, sets a first throttle opening, monitors a crankshaft rotational position, speed, and deceleration, sets a second throttle opening for a predetermined duration if a piston simultaneously crosses a target position below a target engine speed and below a target degrees of rotation remaining, sets a third throttle opening, and determines if an engine speed is below a threshold speed before setting a fourth throttle opening when the engine speed is below the threshold speed, and causes the piston to rest in a predetermined position range.

A method for operating an oxycombustion engine system includes passing a nitrogen-depleted gas, a fuel, and a recycled exhaust gas into a combustion chamber, combusting a mixture of the nitrogen-depleted gas, the fuel, and the recycled exhaust gas, thereby producing an exhaust gas including carbon dioxide, detecting a pressure of the recycled exhaust gas passed to the combustion chamber, determining whether the detected pressure of the recycled exhaust gas is less than a configurable pressure threshold, and in response to determining that the detected pressure of the recycled exhaust gas is less than the configurable pressure threshold, increasing the pressure of the recycled exhaust gas passed to the combustion chamber.

In exemplary embodiments, methods, and systems for multivariable torque control of a vehicle are provided. The method includes configuring a processor disposed of in a multivariable controller to determine a set of references associated with Exhaust Gas Recirculation (EGR) by implementing an algorithm based on engine temperature and at least one reference associated with the EGR to generate commands for the control of a set of actuators; Optimizing at least one cam phase position by the control based on a generated command to apply an appropriate level of engine torque for vehicle propulsion; Restricting an allowable range of cam phases associated with operations of an EGR valve for a set of cams based on amounts of humidity and EGR introduced by the EGR valve during an internal combustion phase of vehicle operation; and providing an amount of propulsion torque by an engine in accordance with instructions provided by the processor.

A turbo-boost controlled intake system is disclosed that provides a driver of a vehicle with greater control over vehicle performance. The turbo-boost controlled intake system includes a control module that is coupled with an aircharger air intake. The control module instructs an electronic control unit of the vehicle to increase manifold pressure to a higher level before releasing the pressure through a waste gate so as to provide a greater power output of the engine. The turbo-boost controlled intake system further includes a wiring harness and a signal adjuster. The wiring harness couples the control module with a turbo inlet pressure sensor, a manifold absolute pressure sensor, and an electronic control unit of the vehicle. The signal adjuster includes a rheostat that enables manual adjustment of the power output of the engine.

A method for diagnosing fuel leakage of a vehicle includes: measuring a pressure of a fuel tank by a pressure sensor in a closed state of a fuel system during starting-off of the vehicle; measuring an inner temperature of the fuel tank by a temperature sensor; and diagnosing, by a controller, whether or not leakage occurs by performing different leakage diagnoses depending on a pressure condition of the fuel tank. Thus, the controller performs a first leakage diagnosis when a pressure value of the fuel tank, measured in the measuring the pressure of the fuel tank, is within an atmospheric pressure level; performs a second leakage diagnosis when the pressure value is higher than a positive pressure; and performs a third leakage diagnosis when the pressure value is lower than a negative pressure.

Methods and systems are provided for controlling a vehicle engine to reduce engine knock and increase fuel efficiency by reducing hydrocarbon breakthrough. In one example, a method may include adjusting a compression ratio of a variable compression engine in response to hydrocarbon breakthrough above a threshold from a fuel vapor canister of an evaporative emissions system.

Methods and systems for calculating a plurality of aging factors in a system operating an engine. The calculated aging factors may include one or more of fuel injector drift, exhaust gas recirculation valve obstruction, and mass air flow sensor bias. Mass flow throughout the system, and pressures and temperatures within the system, are observed in an approach that relies on mass preservation concepts to estimate fuel injector drift, exhaust gas recirculation valve obstruction, and mass air flow sensor bias.

A method of operating an engine is provided. The method includes determining a temperature and a pressure of intake air, and a temperature and a pressure of exhaust generated by the engine. The method includes determining a work performed by the engine based at least on an engine speed of the engine, and determining heating losses of the engine. The method includes determining an enthalpy of the intake air based at least on the work, the heating losses, a heating value of a fuel used for combustion within the engine, and the temperature and the pressure of the exhaust. The method includes determining a humidity value of the intake air based on the enthalpy, temperature and pressure of the intake air and determining an amount of NOx based on the humidity value. The method further includes controlling an operation of the engine based on the determined amount of NOx.

Control techniques for a turbocharger of an engine utilize a wastegate valve configured to divert exhaust gas from a turbine of the turbocharger that is rotatably coupled to a compressor of the turbocharger. A controller is utilized to obtain a torque request for the engine, determine a target compressor power based on the engine torque request, determine a normalized target turbine power based on the target compressor power, determine a target position for the wastegate valve based on the normalized target turbine power and a normalized exhaust flow, and actuate the wastegate valve to the target position. Such control techniques involve the actual calculation of much less intermediate parameters, such as target turbine pressure ratio, which results in more efficient calibration and implementation.

Methods and systems for operating an engine during conditions where ambient humidity changes over time are presented. In one non-limiting example, an engine air flow limit is adjusted to increase engine air flow during high humidity conditions such that an engine may provide equivalent torque output during the high humidity conditions as compared to when the engine is operated during low humidity conditions.