I do not think so. The power of the internal combustion engine lies in the expansion inside the chamber. Injecting in the liquid phase adds to the expansion in the ignition. Inside the combustion chamber there is not a problem of too little heat for expansion; heat removal is part of the limits of efficiency.
Liquids don't compress. Gases do. If the vapor could be introduced into the cylinder, the compression stroke would compress much more vapor than atomized gasoline, which would result in a much more powerful ignition.
A lot of the energy of the combustion cycle is taken up by forcing gasoline to undergo a state shift from liquid to vapor and then explode. Eliminate that phase shift and you're bound to liberate more usable energy.