Single fuel filter 3000 miles and it is changed again and again...

OK Long title but here is the scoop.
Owner has a 2019 Peterbilt 389 with DD60 and 13spd. Partial VIN OD498489.

I have tried a Davco and Paccar filter both were the same, plugged within 3000 miles. The truck has about 255,000 miles on it and last year had much more pull than this year. The last filter I took out was black in 2500 miles. As I drive the fuel Filter Pressure will climb to about 10PSI and then within 300 miles pressure goes well over 15PSI. Truck is real sluggish at 8PSI. I now carry 2 filters and the stuff to roadside change it.

I fuel mostly at Loves for the clean showers. I also use Pilot, Cenex and TA. Many of the threads I read suggested the problem was Bio fuel in winter. YEP That is what I am buying between North Dakota runs and South Alabama runs it has been about the same. Lime green fuel with winter additives.

The biggest concern is the fuel mileage has dropped in half. Changing the filters is pretty much weekly now too. While hauling 25-30,000 pound loads I can barely pull a hill anymore. Last year I would get about 5mpg loaded and 7.5-8mpg empty. Mostly now it is 3mpg maybe 5mpg empty. We just had the Upper head Service, whatever they called it at the dealer but they left a plugged fuel filter in the truck and did not check the injector timing or anything else. Just pulled valve cover gasket. They said blowby and all was within spec, but gave no numbers. Oil flows real good out the vent. Makes the polished fuel tanks real pretty with a fuzzy black coating.

I did run the tanks down to 10 gallons and looked inside with a good flashlight. They looked real clean and I could not find any sediment on the bottom.

If anyone has experience with these Fitzgerald rebuilds it would be great. The motor was a 1999 build. I cannot find any tag or label telling more. Maybe I am not looking in the right place. On Drivers Side mid block is an Emission Plate Identifying the motor as 1999 as in most gliders.

 

Well I have read twice that the injectors may leak back. Mostly Cummins had coolant leak back and also like R&R said Combustion gases. I will keep extra filters in the truck. At least now I have a good kit setup for a 5 minute filter change out. Getting the power and mileage back would be nice for the owner too. Maybe I can find a good injector shop close to Joplin Mo. familiar with this issue. If anyone else has ideas it is always good to know. Thanks for all the ideas.

 

Well I am on filter number 6 now.ileage went up some. 4.3 loaded and 5.7 empty. It still does not pull quite the same but I am going with algae. It seems to be the most plausible since no red dye from coolant or black in tanks from exhaust gasses. The filters are expensive, but is the bosses problem. I am thinking someone bought gas from a cheap lot lizard station and it is slowly working itself clean.

The last 3 filters came out black as night and kind of looked fuzzy. I am not sure the brands but they were white when they went in. The fuzz could also just be the element breaking down.

I hate to see what happens over the next week while I take care of the wife. She was cured of cancer and has her last repair surgery next week. 40 Years together and she had me real worried. This surgery is just to make things comfortable, so we are hoping for a week off, eating ice cream and watching old movies. Then back to the truck and it's problems.