2001 Town Car began starting "hard" when the weather turned cold. Mechanic did a tune up this weekend and it started fine but the weather was in the 50's. Today, the temperature is in the 30's and it's been raining all day with snow expected. Had to put the gas down and "nurse" it until engine warms up or it will die. Once warm, it will start every time.
It could be several things. My first concern is the fuel pump. Has the pressure been checked? It may have a 'lazy' pump. Basically, not enough pressure to start it on cold days but enough to maintain it.
Next, there is a temp switch that tells the computer the outside temp so it can provide the proper fuel ratio based on temps.