My 2006 diesel truck with a 6.0 is blowing a lot of white smoke on start up sometimes or when running starts jerking

This link should help:

https://www.askmehelpdesk.com/cars-t...ml#post1977241

The white smoke on start up is because your glow plugs either aren't coming on or aren't coming up to temp. The jerking, if it does it only when the motor is cold is simply loaded up cylinders from the plugs not heating. If it does it even after up to temp then you have a sticking injector. If it's a Ford 6.0 this would not surprise me. The injectors are notorious for sticking. Try running some seafoam through your fuel. May or may not fix the jerking and clean all the built up oil out of the injectors. Another thing you can try is to cycle the glow plugs 2 or 3 times before you start the truck. If this resolves the white smoke then the plugs aren't coming up to temp. Whether this resolves the smoke or not I would start with the glow plug relay as they are also a notorious culprit