lose no time (in) (doing something)
To do something immediately or as expediently as possible. Wow, Sarah lost no time finding a new boyfriend after she and Rob split up. We have to have the application in by tomorrow morning, so we must lose no time in getting all the signatures we need.
lose/waste no ˈtime (in doing something)
do something quickly and without delay: As soon as she arrived back home, she lost no time in visiting all her old friends.