sunfire gt enige sputters

Hi there new to forum. I have a 1997 sunfire gt 2.4l 5sp, just recently it started to sputter when you first push down on the gas pedal its right at the beginning then its fine. I have had it stall out a few times when leaving a light and it does it in all gears and speeds just the first little bit then its fine. Power is still there. I have noticed that it really smells of unburnt fuel when I shut it off, and it really runs rough when its cold and go figure it just started to get cold around my parts. any advice would be greatly appreciated. Thanks in advance

Thanks for all the replies, much abliged:( Figured out the problem. For all those with the 2.4l look to the right of the throttle body there should be a little black sensor all by itself, hooked to a black metal clip, if you look at the bottom of it, it has a rubber hose going to the bottom center of the t/b I found mine was cracked and broken. I replaced it and now no more sputtering. Hope this helps someone else out with the same probs.