Could I have a fuel filter or fuel pump problem? Maybe some bad gasoline?

What is your question?

My 2009 Ford Focus starts every time, but recently has hesitated to tach up or completely refused to tach up, regardless of accelerator pedal position. It seems the problem gets worse as the engine warms, more hesitation the longer you drive it. No "check engine" or any other trouble lights on. I've replaced the spark plugs and had fuel injection cleaning done at last oil change, no improvement. It has the 2.0L engine, 5 speed stick with 56,000 miles, I drive a company vehicle during the week and the Focus just on the weekends. This afternoon it almost stranded me at a hilltop intersection, would not rev up.

What makes this problem better or worse?

It gets worse the longer the car is driven.

How long has your 2009 Ford Focus had this problem?

13 days