rev up

verb3

1. •
   To increase the speed of an engine, especially that of a stationary motor car.

   • The huge Rolls-Royce engine revved up. Then the back wheels spun furiously, and clouds of smoke filled the air. — 2017
2. •
   (slang) To make (someone or something) more active; to energize.
3. •
   (slang) To become more active.

   • I didn't much want to leave again, but, though I'm not sure I exactly understand why, I just knew I had to rev up again to play this thing out. — 2005