It may help some, but the best way to reduce smoke is to use RedLine Diesel Fuel Catalyst - available at many auto stores - I get it at Pep Boys. I've used it in both the CD and SD since they were new and even on heavy acceleration, they do not smoke at all.
I was a bit disturbed to see the black gunk come out of the return line and back into the bottle. ...[/QUOTE said:Hi
That "black gunk" you see coming back to the bottle in the return hose is from deteriorated jumper return lines between your injectors.
HiActually its sludge caused by the carbon in diesel.