Lately when going to start my car it will start and rev to about 3500-4000 and then die. It usually takes 2 or 3 starts for it to idle properly. This only happens sometimes. The weather by me has been very cold, can that be a cause? It is a 1.8t.

 

I would be looking at your throttle body, it sounds like it either has carbon build up on the butterfly valve, or its straight up sticking. Take off the intake hose to it and spray the living crap out of it with brake cleaner and wipe it off with a rag.