Treatment of engine blow-by gases

The present invention relates to internal combustion engines and particularly to the treatment of blow-by gases in such engines. A method and system of treating blow-by gases within an internal combustion engine, the engine () including at least one combustion chamber (), a dual fluid fuel injection system () for delivering a metered quantity of fuel entrained in compressed gas to the at least one combustion chamber (), the injection system () having a compressor () for supplying the compressed gas, the method including using the intake vacuum of the compressor to draw the blow-by gases from within the engine for subsequent delivery by the injection system to the at least one combustion chamber.