I've been seeing more black smoke recently and I know that I'm about due for a fuel filter change. Is there more smoke because the filter is getting old or is it something unrelated? I just got back from a 500 mile trip pulling a 12K trailer so the truck has been working, it's not like I've been babying it and the soot built up. Just curious. Thanks

Check Air Filter Diesels Really Smoke If Air Filter Is Plugged Up.

A Diesel needs all the Air they can get !! :D

Logically it should smoke more on a clean fuel filter than a dirty one since there would be less fuel restriction. Clean fuel filter + dirty air filter = smoke screen.

Actually, this is one that confuses people. "It smokes so it must have plenty of fuel." is a myth. Quite often Dmax will smoke more when there is insufficient fuel supply as it lengthens the pulse as psi drops creating a longer, less efficient injection event. This is why lift pumps are such a nice addition.

In other words when it wants "xx" mm3 it delivers whether it's done in 1600ms or 2400ms as a crude example.


Filter life verification:

http://www.kennedydiesel.com/images/Dmax-fuel-filter-rest1.gif

Makes sense. I never thought about the computer varying the pulse width to get a certain volume of fuel. I gotta quit hanging around the carburetor guys here at work!:D