AIR FUEL RATIO CONTROL METHOD AND AIR FUEL RATIO CONTROL APPARATUS OF LPG ENGINE

摘要

An object of the present invention is to determine a fuel composition of an LPG to be used for an LPG engine without increasing the cost and to control the air-fuel ratio appropriately. According to the present invention, there is provided an air-fuel ratio control method performed by an air-fuel ratio control apparatus that continuously detects an exhaust state through exhaust emission detecting means provided in an exhaust pipe of an LPG engine and adjusts a fuel injection amount by feedback control, The control device causes a change in the output signal of the exhaust gas quality detecting means by performing a predetermined operation so as to determine the fuel composition of the LPG currently used by the predetermined determination method on the basis of the change and is reflected in the subsequent air- .