Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, in response to an electric motor driving an electric compressor positioned upstream of a turbocharger compressor disposed in the intake passage, a position of a valve in an exhaust gas recirculation (EGR) passage coupled between the intake passage and the first exhaust manifold may be adjusted based on a pressure in the first exhaust manifold.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, in response to an electric motor driving an electric compressor positioned upstream of a turbocharger compressor disposed in the intake passage, a position of a valve in an exhaust gas recirculation (EGR) passage coupled between the intake passage and the first exhaust manifold may be adjusted based on a pressure in the first exhaust manifold.

An air flow measurement device that measures an air flow rate based on an output value of a sensing unit attached in an environment in which air flows, the air flow measurement device is provided. The air flow measurement device may calculate an average air amount, which is an average value of the air flow rate, from the output value. The air flow measurement device may calculate a pulsation maximum value, which is a maximum value of the air flow rate, from the output value.

An engine management apparatus for a vehicle having a fuel ratio controller arranged to control the air to fuel ratio of a fuel mixture for the vehicle's engine, a power demand sensor arranged to sense power demands made of the engine, and an engine controller configured to increase the air to fuel ratio from a first selected value to a second selected value in the event that the rate of vehicle speed change is less than a first threshold and the demand is less than a second threshold.

An engine management apparatus for a vehicle having a fuel ratio controller arranged to control the air to fuel ratio of a fuel mixture for the vehicle's engine, a power demand sensor arranged to sense power demands made of the engine, and an engine controller configured to increase the air to fuel ratio from a first selected value to a second selected value in the event that the rate of vehicle speed change is less than a first threshold and the demand is less than a second threshold.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, one or more valves of a set of first exhaust valves coupled to the second exhaust manifold may be deactivated in response to select engine operating conditions, while maintaining active all valves of a set of second exhaust valves coupled to the first exhaust manifold. The select engine operating conditions may include one or more of a deceleration fuel shut-off condition, a part throttle condition, and a cold start condition.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, one or more valves of a set of first exhaust valves coupled to the second exhaust manifold may be deactivated in response to select engine operating conditions, while maintaining active all valves of a set of second exhaust valves coupled to the first exhaust manifold. The select engine operating conditions may include one or more of a deceleration fuel shut-off condition, a part throttle condition, and a cold start condition.

Methods and systems are provided for aging a new plastic fuel tank in a vehicle. In one example, during a plug-in event to recharge a battery of the vehicle, the fuel tank is isolated and the fuel pump is actuated to agitate fuel within the tank and increase fuel vapors until the plastic fuel tank becomes aged to a predetermined degree by fuel vapors generated therein. In this manner, the fuel tank is aged more rapidly, resulting in more accurate fuel level readings and less noise and vibration.

Methods and systems are provided for aging a new plastic fuel tank in a vehicle. In one example, during a plug-in event to recharge a battery of the vehicle, the fuel tank is isolated and the fuel pump is actuated to agitate fuel within the tank and increase fuel vapors until the plastic fuel tank becomes aged to a predetermined degree by fuel vapors generated therein. In this manner, the fuel tank is aged more rapidly, resulting in more accurate fuel level readings and less noise and vibration.

There is provided a system for monitoring an engine. The system includes a processor. A memory including instructions that, when executed by the processor, cause the processor to perform certain operations. The operations may include receiving a first data set and a second data set. The first data set being sampled at a first rate and the second data set being sampled at a second rate, where the first and second rate are different. The operations further include determining, based on a number of occurrences in either the first data set or the second set, whether an event that has occurred in the engine has occurred a predetermined number of times. The operations further include recording the first data set as an output in response to the number of occurrences exceeding the predetermined number of times, and in the contrary recording the second data set as the output. The operations may include computing a ratio of a fast recording process to a slow recording process and adjusting an output file size according the ratio. Another feature may be a look back subsystem that backfills an interval of pre-event fast recordings when an event is detected. The system can self-adjust thresholds to maintain file size constraints during unusually active or eventful flights.