Black 07 Corolla CE
So my car has been sitting for a few weeks while I gathered parts. I finally got her back on the road. my commute to work is only a few minutes. Yesterday I just started the car and drove to work, not expecting the heat to be very effective on such a short route. Today was considerably colder so I decided to "warm'er up". The car ran for about 15-20 minutes before I got in. I got in, turned the heat dial all the way up, put the selector on "Defrost/Feet" ... Luke warm air blasted into the cabin...WTF. After playing with ALL the dials for a few minutes, I decided to just get to work and ask the "ToyotaNation". about a half mile in, HOT air started coming out, but it went back to warm very soon. Then it got hot again. almost matching my acceleration. I'm thinking a vacuum line but have NO IDEA where to look/start. Any suggestions?