Lancer can't holde the RPM on idle!
 

I have a 2003 Lancer OZ Rally, AT. A few days ago, I went to start the car after work (so the cars stood outside in the cold for at least 8 hours). I tried to start it, but it did not. It was like it needed help with the acceleration pedal. So, i tried a few times, but the RPM was going down each time, the car was just like a half starting, if you can say so. So I decided to help it out by pressing the acceleration pedal (like I was doing when I was a kid in an old-old car). So, the car did start, but on my attempt to take the foot out of the acceleration pedal, the RPM was going down and the engine was shutting off. So, I started one more time (by pushing the acceleration pedal) and then I was just keeping my foot on the pedal at around 1.5k rpm for a while and after that it was able to keep the RPM up. Still low, but not completely off. I thought it is because of the cold :).
Next morning I did not have the same problem, but now the car was keeping 2000RPM at idle! I know it is cold (about 32 degrees) but it spent my last winter in WY at lower temps, and did not have these problems.
Today, I was going to work and the engine just stopped when idle at a stop light. So I had to do the same thing, helping with the acceleration pedal to start the engine.

Can somebody tell me what is wrong?