This was abnormal in that it never slows up more than a 1 or 2 mph unless the grade is really steep. I suspected the fuel filters.
There may have been a couple of mitigating circumstances, but I had done something I rarely do; ran the tank down to around 1/8th full. I knew I was going to stop at the Flying J near Beaumont and I had plenty of fuel to get there. I will also say we bought fuel south of Lake City on I-75 just before we got on I-10, so we had been a bunch of miles before this became an issue.
I think part of my problem stemmed from having the fuel level that low and driving across an extremely rough section of I-10. The sloshing must have stirred up sediment / water in the bottom of the tank as the primary filter (Racor 1000FF Turbine Separator) had an inordinate amount of water in it and the filter was covered in crud. This is a Racor 2020 30 micron fuel filter element.
I changed both the primary and secondary yesterday and the engine is running normally with plenty of power. During the restricted fuel flow driving, the turbo boost would max around 12 to 13. It runs 15 now.
I know I am not the first one to experience this, but I you need to have both of those filters IN YOUR COACH unless you want to experience a potential unwanted delay or problem. Regardless of if you change them or you get someone to do it, not being able to get the filters out in the middle of BFE Arkansas in the evening on Sunday will be the issue.
They are not hard to change and you need to make sure you fill them when you change them and the Racor filter holds a lot of diesel. Having an empty gallon oil jug with you to fill full of diesel is a good idea.
And don’t forget to write the mileage and date on the filter with a Sharpie.