1995 BMW 530i rough idle

The car has been great for years now suddenly as it gets warmer the car seems to idle rough especially in the cooler mornings

acceleration can be laggy at times
you really notice the problem at a stop light when the car is bucking around and vibrating, once I get on the gas to go the engine smooths out around 1000 rpm and it's good to go till the next light

what should I do to fix this?

I haven't tried anything yet

thanks in advance

R.