[QUOTE=Miramichi;. I have a hard time believing that to be the culprit as clogged fuel filter would counter act producing black smoke.
Black smoke typically is produced due to low air to fuel ratio and burning too rich. Meaning all of the diesel isn't burned off and in turn voila black smoke. Have you checked your air filter? There is an indicator for it. It also wouldn't hurt to throw some injector cleaner into your tank. RV's aren't driven as much as SEMI's and things can get clogged up.
I agree mostly, but i have had the occasional rich burn when a cylinder drops out due to a partially clogged fuel filter. I seen this many time on stationary equipment, (generators with mechanical pumps) but not on road vehicles.
I would lean toward the lack of sufficient air to complete the burn. Since you are not having this issue on a constant basis, I'd rule out but not completely, a bad or going bad turbo charger. The only time I've seen a turbo contribute to smoking is when it went completely out, so this may be far fetched.
It was mentioned above an exhaust restriction in the form of your exhaust brake hanging toward the close position. I'm leaning this way because I've seen this one first hand happen on the cat motors. I would pay attention to that possibility and check it out.
Dan & Loretta, US Army Retired Aero Scout Pilot
2012 Fleetwood Providence 42P Class A/DP
Spartan Chassis, 8.9L Cummins 450HP