Abstract:
Methods and systems for simultaneously operating port fuel injectors and direct fuel injectors of an internal combustion engine are described. In one example, operation of a port fuel injector is deactivated in response to an indication of reduced performance of a direct fuel injector so that degradation of the direct fuel injector may be reduced.
Abstract:
Methods and systems for simultaneously operating port fuel injectors and direct fuel injectors of an internal combustion engine are described. In one example, different duration port fuel injection windows are provided to maximize fuel injection amount and improve accuracy of an amount of fuel injected during a cylinder cycle via port and direct fuel injectors.
Abstract:
Methods and systems are provided for restarting an engine when a high pressure fuel pump is degraded. In response to an indication of high pressure fuel pump degradation, fuel may be injected during an intake stroke, rather than a compression stroke, for a selected number of combustion events since the engine restart. By shifting to an intake stroke injection, the engine may be started even when sufficient fuel rail pressures are not available.
Abstract:
Methods and systems are provided for controlling fuel injectors for a fuel system configured to deliver fuel to an engine via each of port fuel injection and direct fuel injection. In one example, a method may include, during an engine green start condition, injecting fuel with the port injector while not injecting fuel with the direct injector, and after the green start condition, injecting with each of the port injector and the direct fuel injector at a fuel ratio determined based on engine operating conditions.
Abstract:
Methods and systems are provided for reducing lean air-fuel ratio excursions due to degradation of a port injector while fueling an engine via each of port and direct injection. During a PFDI mode of engine operation, responsive to an indication of port injector degradation, such as due to circuit or injector power issues, intake airflow is limited by reducing the opening of an intake throttle. Air flow is limited to be based only on the direct injected fuel fraction, and independent of the commanded port injected fuel fraction.
Abstract:
Methods and systems for simultaneously operating port fuel injectors and direct fuel injectors of an internal combustion engine are described. In one example, operation of a port fuel injector is deactivated in response to an indication of reduced performance of a direct fuel injector so that degradation of the direct fuel injector may be reduced.
Abstract:
Methods and systems are provided for reducing lean air-fuel ratio excursions due to degradation of a port injector while fueling an engine via each of port and direct injection. During a PFDI mode of engine operation, responsive to an indication of port injector degradation, such as due to circuit or injector power issues, intake airflow is limited by reducing the opening of an intake throttle. Air flow is limited to be based only on the direct injected fuel fraction, and independent of the commanded port injected fuel fraction.
Abstract:
Methods and systems for simultaneously operating port fuel injectors and direct fuel injectors of an internal combustion engine are described. In one example, different duration port fuel injection windows are provided to maximize fuel injection amount and improve accuracy of an amount of fuel injected during a cylinder cycle via port and direct fuel injectors.
Abstract:
Systems and methods for improving fuel injection of an engine that includes a cylinder receiving fuel from two different fuel injectors is disclosed. In one example, fueling errors for each of the two fuel injectors are determined based on fractions of fuel supplied by the two fuel injectors during different engine operating conditions.
Abstract:
Methods and systems are provided for restarting an engine when a high pressure fuel pump is degraded. In response to an indication of high pressure fuel pump degradation, fuel may be injected during an intake stroke, rather than a compression stroke, for a selected number of combustion events since the engine restart. By shifting to an intake stroke injection, the engine may be started even when sufficient fuel rail pressures are not available.