misbehave (for people); not work properly (for machines)."The babysitter had a difficult time because the children acted up all evening." "I guess I'd better take my car to the service. It's been acting up lately."
malfunction, operate abnormally; behave strangely or abnormally; behave in a disorderly manner, behave disobediently; show off, behave in a way that draws attention to oneself