Bad cough in my cummins
 

I just bought a 95 12v and it coughs white smoke when I start it. And it will cough when I give it throttle and then clears up after a minute. But After 2000rpm it won't clear up. And it idles at 500rpm. The truck is bone stock and has 211*** miles. It is a 5spd and has previously been a service truck. It sat since 2/2013. I need some ideas before I get into it.

You may want to have the injectors checked.

pull fuel filter and fill with ATF, then run the truck up and down the road, it sounds like your fuel has alge in it , when you pull your fuelk filter dump contents into a clean clear jar, if its not clear , you have junk in tank... pull filter and go from there... start simple, then work your way up