Abstract: Methods and systems are provided for balancing a plurality of fuel injectors. In one example, a method includes adjusting port-fuel injecting parameters in response to a learned direct injector fueling error.

Abstract: Methods and systems are provided for balancing a plurality of fuel injectors. In one example, a method includes adjusting port-fuel injecting parameters in response to a learned direct injector fueling error.

Abstract: Methods and systems are provided for accounting for a difference between an expected amount of fuel scheduled to be delivered and an actual amount of fuel delivered to an engine cylinder during a fueling event. In one example, a method may include scheduling a direct injection to a cylinder based on an estimated expected amount of fuel injected to the cylinder during an immediately previous injection event. The expected amount of fuel injected during the immediately previous injection event may be a function of an average fuel rail pressure during the immediately previous injection event.

Abstract: Methods and systems are provided for estimating a temperature of a direct injector. In one example, a method may include estimating the temperature of the direct injector based on a resistance of a solenoid coil of the direct injector. In one example, a pulse-width of the direct injector during an opening phase is adjusted in response to the temperature.

Abstract: Methods and systems are provided for balancing a plurality of fuel injectors. In one example, a method includes adjusting direct injector parameters in response to a learned direct injector fueling error. The pulse-width supplied to the direct injectors is adjusted to balance cylinder fueling.

Abstract: Methods and systems are provided for accounting for a difference between an expected amount of fuel scheduled to be delivered and an actual amount of fuel delivered to an engine cylinder during a fueling event. In one example, a method may include scheduling a direct injection to a cylinder based on an estimated expected amount of fuel injected to the cylinder during an immediately previous injection event. The expected amount of fuel injected during the immediately previous injection event may be a function of an average fuel rail pressure during the immediately previous injection event.

Abstract: Systems and methods for improving accuracy of an amount of fuel injected to an engine are disclosed. In one example, holding current of a fuel injector is adjusted to follow a fixed period and timing of a fuel injector off command is adjusted according to attributes of fuel injector holding current so that a fuel injector may provide a requested fuel amount. The fuel injector off command may be adjusted according to an amount of holding current that is expected to be flowing through the fuel injector at a time when the fuel injector is commanded off.

Abstract: Systems and methods for improving accuracy of an amount of fuel injected to an engine are disclosed. In one example, timing of a fuel injector off command is adjusted according to attributes of fuel injector holding current so that a fuel injector may provide a requested fuel amount. The fuel injector off command may be adjusted according to an amount of holding current that is expected to be flowing through the fuel injector at a time when the fuel injector is commanded off.

Abstract: Systems and methods for improving accuracy of an amount of fuel injected to an engine are disclosed. In one example, a maximum holding current of a fuel injector is adjusted so that a holding current of a fuel injector is equal to a predetermined value when the fuel injector is commanded to cease injecting fuel.

Abstract: Methods and systems are provided for reducing errors in estimated fuel rail pressure incurred at the time of a scheduled injection event due to engine-driven cyclic fuel rail pressure changes. In one example, a pulse-width commanded during a scheduled injection event is determined as a function fuel rail pressure samples collected over a moving window that is customized for the corresponding fuel injector. In another example, the commanded pulse-width is determined as a function of an average fuel rail pressure sampled during a quiet zone of injector operation and predicted fuel rail pressure altering events occurring between the quiet zone and the scheduled injection event.

Abstract: Methods and systems for adjusting timing of fuel injectors to reduce cylinder to cylinder air-fuel maldistribution are disclosed. In one example, fuel injection timing is adjusted as a function of pressure ratios that are based on fuel rail pressures observed during injection of fuel. The pressure ratio may be a ratio of a root-mean-square pressure and a scheduling fuel pressure.

Abstract: Methods and systems are provided for relieving pressure from a compression locked engine. The engine may be compression locked during an engine start attempt due to operator application of a manual transmission clutch at or around the time of a first combustion event of the engine start. A direct injector of the compression locked cylinder is commanded open to relieve the pressure into the fuel rail.

Abstract: Methods and systems are provided for injector balancing without disabling a cam actuated high pressure fuel pump. In one example, one of a plurality of cam lobes of the pump is selectively and sequentially disabled while a group of injectors are concurrently operated to learn a pressure drop across each injector. The selection of the injectors is based on the identity and stroke timing of the disabled cam lobe.

Abstract: Methods and systems are provided for reducing errors in estimated fuel rail pressure incurred at the time of a scheduled injection event due to engine-driven cyclic fuel rail pressure changes. In one example, a pulse-width commanded during a scheduled injection event is determined as a function fuel rail pressure samples collected over a moving window that is customized for the corresponding fuel injector. In another example, the commanded pulse-width is determined as a function of an average fuel rail pressure sampled during a quiet zone of injector operation and predicted fuel rail pressure altering events occurring between the quiet zone and the scheduled injection event.

Abstract: Methods and systems are provided for reducing errors in estimated fuel rail pressure incurred at the time of a scheduled injection event due to engine-driven cyclic fuel rail pressure changes. In one example, a pulse-width commanded during a scheduled injection event is determined as a function fuel rail pressure samples collected over a moving window that is customized for the corresponding fuel injector. In another example, the commanded pulse-width is determined as a function of an average fuel rail pressure sampled during a quiet zone of injector operation and predicted fuel rail pressure altering events occurring between the quiet zone and the scheduled injection event.

Abstract: Methods and systems are provided for reducing errors in estimated fuel rail pressure incurred at the time of a scheduled injection event due to engine-driven cyclic fuel rail pressure changes. In one example, a pulse-width commanded during a scheduled injection event is determined as a function fuel rail pressure samples collected over a moving window that is customized for the corresponding fuel injector. In another example, the commanded pulse-width is determined as a function of an average fuel rail pressure sampled during a quiet zone of injector operation and predicted fuel rail pressure altering events occurring between the quiet zone and the scheduled injection event.

Abstract: Methods and systems are provided for learning a cylinder-to-cylinder air variation. During conditions when a PFDI engine is operated in a port-injection only mode, prior to port fuel injection, a direct-injection fuel rail pressure may be lowered via direct-injection. Then, prior to a spark event in a port-injected cylinder, the direct-injector may be transiently opened to use the rail pressure sensor for estimating a cylinder compression pressure, and inferring cylinder air charge therefrom.

Abstract: Methods and systems are provided for injector balancing without disabling a cam actuated high pressure fuel pump. In one example, one of a plurality of cam lobes of the pump is selectively and sequentially disabled while a group of injectors are concurrently operated to learn a pressure drop across each injector. The selection of the injectors is based on the identity and stroke timing of the disabled cam lobe.

Abstract: Methods and systems are provided for reducing errors in estimated fuel rail pressure incurred at the time of a scheduled injection event due to engine-driven cyclic fuel rail pressure changes. In one example, a pulse-width commanded during a scheduled injection event is determined as a function fuel rail pressure samples collected over a moving window that is customized for the corresponding fuel injector. In another example, the commanded pulse-width is determined as a function of an average fuel rail pressure sampled during a quiet zone of injector operation and predicted fuel rail pressure altering events occurring between the quiet zone and the scheduled injection event.

Abstract: Methods and systems are provided for reducing errors in estimated fuel rail pressure incurred at the time of a scheduled injection event due to engine-driven cyclic fuel rail pressure changes. In one example, a pulse-width commanded during a scheduled injection event is determined as a function fuel rail pressure samples collected over a moving window that is customized for the corresponding fuel injector. In another example, the commanded pulse-width is determined as a function of an average fuel rail pressure sampled during a quiet zone of injector operation and predicted fuel rail pressure altering events occurring between the quiet zone and the scheduled injection event.