running at about 85-90 clicks, engine with a bit of a load feels like a gas endine with the choke on. I suspect fuel filter (but indicators say 75% left), or water in fuel. This is a diesel . Also, it seems very sluggish. When it was bucking one day, I realized I had the accelerator on the mat.
the fuel filter indicator is simply a mathematical formula based on time and driving. I do not believe there is anything in that system to actually test the fuel.
Where I live, diesel fuel is not all the same. Some is good quality, some is full of dirt and will clog filters super quick. Fuel filters are cheap. Draining the fuel/water separator is easy. Do both and see if there is improvement.
beyond that: any check engine lights on?