MY024runner

I was wondering if anyone had this problem or know if its normal that lets say you are at a stop light then you don't gun or floor the gas pedal, but just tap the gas pedal quick when its green then you hear a little click sound like some old cars that can't climb a high hill. It only clicks once though not like old cars that can't climb a hill many clicks. Hope this makes sence. I was wondering if this was normal or has anyone have the same prob and know what it is? Thanks to all in advance.