I recently bought a 1995 F250 7.3L Powerstroke. It drove perfectly fine for the first week or so, but on my way to work, it stalled and wouldn't start. I replaced the CPS and the mechanical pump on it and it started up perfectly fine. After driving it for a few days the truck died again. I am stumped at this point. What do you think? I did notice that there is some oil leaking from underneath the truck from somewhere in the engine. I have no idea where it's coming from though. Oh, and when I started the truck right before it died, it had some trouble starting and when it did start, there was a large white cloud of smoke that came out. Any help would be great, thanks.