METHODS AND SYSTEMS FOR DETERMINING A FUEL CONCENTRATION IN ENGINE OIL USING AN INTAKE OXYGEN SENSOR

摘要

Methods and systems are provided for estimating a fuel concentration in engine oil in an engine crankcase. In one example, an engine controller may adjust engine operation such as EGR flow and engine fueling based on the estimated fuel concentration in engine oil. The fuel concentration may be based on an output of an intake oxygen sensor when purge and EGR flow are disabled, engine oil temperature, and fuel composition.

主权项

1. A method for an engine, comprising:
during engine oil warm-up, operating with EGR while purging fuel vapors to an engine intake with purge flow disabled at a first frequency; and in response to a difference between EGR estimated by an oxygen sensor and EGR estimated by a pressure sensor being higher than a threshold, disabling the purge flow at a second, higher frequency.