1993 Honda Civic

We own a 93 honda civic dx, and it has been really acting up. Most of the time it runs pretty good. But then from time to time we really have to crank it and crank it in order for it to start. It was overheating because of the fan not kicking in and cooling it down. Once it starts from cranking and cranking a big cloud of white smoke comes out of the exaust. Once warm it runs pretty good, exept for and ocational amall jerk(it seems as it just wants to shut off for a quick second). I have replaced the fuel filter, thinking that it might be cloged, and that didnt do anything. I checked the oil to see if theres any water and oil mixture, and there wasnt. I dont realy know wut else I can check in order to try and fix it.