Black smoke is a rich fuel mixture so an injector issue is a possibility but before you go too far down that road you should make sure that air is getting into the engine properly. Check the air intake and air filter for any restrictions.
No code has to be inserted here.
I am getting a lot of comments on this and I do appreciate all of them, thanks wayne
so i should have started from the beginning, I lost my fuel pressure so I replaced the fuel pump. Lost all fuel in lines.so I took air hose and put air pressure to the fuel tank. Then I got fuel to the pump. Tractor started run good. Then I saw I had a fuel line leaking. shut the tractor off tightened them. Then put air to the fuel tank again because it wouldnt start again. After that it started but blows out lot of black smoke. I am thinking I may damaged a fuel injector or something else. Thoughts?