Engine overheating problem?

My water pump went out on my car. We replaced it, and the timing belt. ( It is in time). We cranked it up, and filled all of the fluids in the car. It idles high, and when we are driving and coasting to a stop it dies. This morning we drove it, drove good, but then it started smoking really bad. This morning I heard it bubbling. What could be the cause of the overheating?