I'll try to find more info on this, but back in the "80s", GM engineers developed a fuel management injection system implemented on a 350c.i. short block. It was designed to only deliver fuel for the demand cylinder.

The engine was tested in either an Olds or Buick. Although it was claimed to be underpowered both in hp & torque it did reveal significant efficiency in fuel consumpsion and enough power to safely propel the vehicle. That’s 20-year old technology.
I never heard anymore of that project.