I just ran the Gator out of Diesel on accident, and now there is air in the fuel lines. It didn't come with a manual when I bought it from the previous owner so I could use some help. It's a late 90's 6x4 Gator.
Timing is everything. You need to purge the lines AND have the fuel hit WHEN the glow plugs are going. Bleeding at the rail is good enough. Then crank for 7 seconds after the light goes off. Repeat. My Yanmars will typically have an air bubble after replacing the fuel filter similar to what you'd have on a rail purge. Takes 3 cycles or so to get back on line. Also best not to be doing it in -10 weather. Push it in a garage and get some heat going. The battery will be happier too. BTW white smoke is hopefully only water contamination. Purge with clean fuel. Hopefully it isn't heavy fouling on the rings. Stanadyne additive helps with the water condensation and adds Cetane, which both help in the winter.