Well no, its not normal acceleration. The initial 10' is normal. I have two other cars to compare to. And it is a definate, noticable, obvious, rapid change in acceleration, as if the engine just shifted into a submode.

New filters (fuel and air), did the diesel purge thing. When purchased I got fairly steady 23 mpg; after the tune up items mentioned it was very rock steady at 26.x mpg for several months. Now its back to 23-25. Dont know if thats due to whatever is wrong or the need to be frequently forcing downshifts to accelerate.

Other fuel items I will look into. Interestingly, it leaks fuel from the filler cap just enough to leave streaks outside the door a few inches long. The cap fits tightly but I guess the rubber seal is worn.