I have a 2002 Ford Expedition with 95,000 on a 5.4 liter engine. When I give it a soft acceleration it acts as though it has a miss. Under hard power of high rpm's it runs fine. I just replaced the fuel pump, fuel pump relay and fuel filter due to a no start condition. It now starts and runs but it still has the hesitation under soft acceleration. There are no pinched wires or hoses causing flow problems to the engine. I want to do the necessary repairs myself but due to the electronic ignition and injection I am just wondering if anyone has dealt with this before?

 

Is the fuel pump a motorcraft or a parts store brand? What brand of fuel filter did you use? Was this problem present before the fuel system repairs? Did you take any fuel pressure readings? So many questions

 

What does it do @ 45 mph right after it shifts to OD when accelorating normally. Hows doe it run at that point?

 

I too have a similar problem. Under lite accelleration, when the Tach reads 1000 RPM there is a hesitation that feels like a miss. This happens consistently at 1000 RPM. This problem is more noticable when the engine is warm. I am leaning towards a vacuum leak. Other than that, the engine still runs great...225,000 miles. This past weekend I changed the plugs and replaced the PCV line and rubber elbow that connects to the back of the intake.
Is this similar to the symptoms you are having??