I have a TS110 that after running for about 4 hours, it starts to run rough like it's getting too much fuel. The exhaust is white/blue and is really a heavy diesel exhaust smell. I haven't checked the fuel filter for water yet, but I had added some Cetane booster additive to the fuel for Ford Powerstoke engines. Is this causing my problem or do I potentially have water in the fuel? I use off road diesel and I'm in KS so it's hot now! I'm really hoping this isn't a fuel pump or injector problem. Thanks much!