As far as I understand it, if I pumped the piston repeatedly, compressing the gas, the temperature would go up for a second, but the minute I released the piston the higher pressure inside the container would cause the piston to move back up. The amount of kinetic energy I put into the system by pushing the piston a distance x from equilibrium would be the same as the amount released when the system pushed the piston back towards equilibrium a distance x.
But what if I somehow "pulled" the piston faster than the air could push it back to equilibrium, creating some kind of temporary vacuum? If I did it faster than the average speed of the gas molecules, much less work would be done by the gas and it would keep some of the energy it gained from adiabatic compression--is that correct, or am I missing something?