Car will not start when its freezing outside....?

For the past couple months my car doesn't start when its freezing outside. Sometimes it'll start and other times it doesn't. It's 50/50 really. It sounds fine, it's trying to start, but the engine never gets going. Then sometimes the engine will start but stops a second later, when this happens it usually start after that. Was putting it off because I don't want to spend the money. Brought it to Acura (the car is an '04 Acura TSX) and they couldn't figure out what's wrong with it. So today I brought it to a local guy and he cleaned the throttle body. I just tried to start my car and it doesn't start. Now what?!?! What could it be and what should I do? And should I be out the money I just paid to get this fixed? Thanks