Quote Originally Posted by crazy_boy View Post
sir, how do i de-carbonize a diesel intake manifold? sorry if this is OT. just thinking that black smoke may also be coming from carbon gunk-filled intake manifold.
Best way to decarbonize is to run your engine at high speed and load every once in a while. The higher exhaust temperature fries accumulated soot in the exhaust system; and the higher exhaust volume blows it out.