Patent ID: 6622691
Filing Date: 2003-09-23
Classification: F02B,F02D,F02M,Y02T

Abstract:
A method of operation for an internal combustion engine having a fuel vapor purge system that is selectively activated to purge stored fuel vapor into said engine, said engine being operable in a stratified combustion mode where fuel is injected into a cylinder of said engine to produce a lean air/fuel mixture that is combusted with the purged fuel vapor for achieving a commanded engine power output, the method comprising the steps of:determining a first average air/fuel ratio error when said purge system is not activated and a second average air/fuel ratio error when said purge system is activated; estimating a concentration of fuel in said purged fuel vapor during steady-state operation of said engine in said stratified combustion mode based on a relationship between said first average air/fuel ratio error and said second average air/fuel ratio error; and adjusting a quantity of fuel injected into said cylinder to compensate for said concentration.