The injection at about 15PSI instead of the carb at atmospheric, does a lot better job
of atomizing the fuel. A good part of why injection gives lower emissions and better fuel economy. Of the droplets that get into the cylinder, during the initial burn, only at the surface vaporizes. What burns is the vapor around the droplets. As combustion continues, the heat causes more of the droplet to vaporize. Large droplets probably do not burn and they finally vaporize in the hot combustion gases going out the exhaust valve.
