E150 XLT Power Hesitation During Acceleration!

[leroge]

As I took to the highway this past weekend, I noticed that my engine ( Trinitron V8 ) 'sputtered' when I accelerated at 'higher' speeds ( 40 - 50 MPH ). Felt like very brief hesitations ONLY when accelerating at 'higher' speeds. It was really noticable when I had the cruise control on and acceleration occured while going up hills, for example. The vehicle has 129K miles and works like a champ. Some facts - (1) gas sending device in gas tank and fuel filter replaced at 100K miles, (2) thought problem was related to either gas line freeze or fillup of different gas formula ( in Indiana rather than Illinois ) but added HEET and GUMOUT to fuel tank but problem continued, (3) vehicle works like a champ at low speeds even when accelerating!

Your thoughts? Approach to diagnose?

[leroge]

Eleven views and no ideas? C'mon auto mechanics, how about some thoughts!

[rhandwor]

I used a can of Winn's intake cleaner. I used a can with a valve on it and used a small vacuum hose on the intake. I just added enough to keep from stalling. I also installed new plugs on my 1997 5.4L F-150.
Egr problems will also cause problems.