ka24 sohc problems

[myles88]

So as im driving along my engine jerks violently if i let off the gas, but if i press on the gas its smooths out, and as long as im giving it gas, it is smooth...if im just cruising at a steady speed it doesnt jerk as bad but still does, if i go full throttle it blows white smoke sometimes, then sometimes it blows black smoke, it also stalls a lot when as its warming up, i think it may have something to do with the m.a.f, but im new to these...ANY help would be awesome, if you need more info or have questions just ask...

thanks
myles