After sitting overnight when I first start up my car it runs like crap until it gets warmed up. I believe it is firing on 3 or 4 cylinders, even is if give it some throttle it shakes like hell missing badly. Once it's warmed up it's fine and as long as it doesnt sit more than a few hours it will be fine next time I start it up. What might cause this? Also it seems to smoke a whole lot while its missing.