Patent ID: 7779810
Filing Date: 2010-08-24
Classification: F02D,Y02T

Abstract:
1. A control method for internal combustion engines with gasoline direct fuel injection systems, comprising: receiving a crankshaft position signal from a crankshaft position sensor; interpreting the crankshaft position signal; determining a crankshaft position based on the interpretation of said crankshaft position signal; and during idle operating conditions, reducing a coefficient of variance (COV) of indicated mean-effective pressure (IMEP) relative to single pulse fuel injection by: commanding fuel at a first rate when said position of said crankshaft is within a first selectable range during a combustion cycle of an engine cylinder; commanding fuel at a second rate not equal to zero when said position of said crankshaft is within a second selectable range during said combustion cycle of said engine cylinder; and commanding spark when said position of said crankshaft is within a third selectable range during said combustion cycle of said engine cylinder, wherein commanding fuel at said first rate, commanding fuel at said second rate, and commanding spark are scheduled based on the determination of the crankshaft position.