Hi I have a 96 1 ton. The truck runs good but when I am towing and hit hills or when the engine has to work. The truck blows black smoke out of it bad. I had a new pump on it but I was talked into trying to run bio diesel thru it and it stopped running. It messed everything up. I cleaned out fuel tank, lines, fuel filter, installed new injectors. I have put my old injector pump in the truck that had about 190k on it. and now the smoking problem started. Any ideas before I buy a new pump?