Bucking from stop when cold

I have been experiencing bucking when starting from a stop when the car has not fully warmed up yet. Can hear the exhaust banging around when this happens. I have been getting white smoke/steam from the tail pipe for just a few minutes when cold, disappears shortly after or when I give it a good rev. I am also getting a strong fuel smell like the car is running rich, it idles fine when when cold.

Once the car has warmed up enough, the bucking does not happen. I have been lately letting the car warm up completely before driving it to avoid this problem.


Any ideas what could be the problem?

Thanks!
John