Effect of composition of propane-butane mixture on regulation parametersof SI engine fuel supply system

In the engine fed by means of liquid propane-butane injection, the fuel composition has the substantial influence on the injectors opening time required to realization of the correspondent value of air excess number. In the certain states of engine load the mixture composition might not be corrected properly by lambda sond signal or the necessary correction would have to overstep the possibilities of feeding system. The feeding system controller should be fitted with procedures enabling the correction of calculated injector opening time, according to propane and butane shares in the fuel. Change of the air excess coefficient as the result of a change of fuel composition effects also in exhaust gas toxic components emission level. The results of investigations of SI engine fuelled with liquid propane-butane injection have been presented in article. The influence of composition of P-B mixture on the injection system parameters and exhaust gas toxic components concentration has been defined.