[Shotimes] engine stumbling

[Co-Op]

Essentially what happens is, when I accelerate past 4k, the engine starts to
stutter.  This happens almost every time.  It is not an intermittent problem
Normally, when the car is cool like after leaving work for the day, or
departing in the morning, the car will act fine for a few minutes then
stutter after all fluids are up to temp.  I do have a feeling, while it is
stuttering, of a loss in power.  RPMs will still increase, but not as fast
as normal.
 
 This problem first started on the way home from Indy.  I decided to go WOT
at some point near the WV/PA border.  I got to 95 or 100 an engine started
to stutter.  I figured that I had a tank of bad gas since we had filled up
at some point in OH.  I believe that the fuel was an ethanol mix, and the
Sunoco station that we stopped at was sorta' remote.  I have run 25 gallons
through the car since then and have treated the system to a bottle of
Techron.
 
I have been swapping out what parts I can.  TPS swap, no change.  DIS
module, no problem.  Coil pack, discovered that there are different ones out
there.  I don't have a spare that will work.  Spark plugs, no effect.  LPM
is tight and secure.  Battery is good.  I wanted to check fuel pressure, but
I could not find the adapter for our gauge.  No codes.  Cylinder balance
test was fine.

I haven't yet, but I will be checking voltages at the battery in the trunk,
cables near the alternator, and on the alternator.  Is there a way to check
to see if there is enough current getting to the plugs?  The ones that came
off the car looked great, so I can't see an issue there.  

I'm really at a loss for finding a solution.  My father and I are thinking
that the fuel pump may be going out.  Once I find the rest of our pressure
gauge, I will verify that I have good KOEO, idle, high rpm cool, and high
rpm hot fuel pressure.  The fuel filter is less than a month old, while the
pump is nearing in on 3 years.  I'm fairly certain that it is a Walbro
155lph piece.

 I have ordered new Motorcraft plugs, Accel wires, and a Federal-Mogul fuel
pump from RCM Automotive.  Should be here on Thursday.
 
 
Mike Bruce 

p.s. Yes, It does seem like I post a new problem every few weeks.  I deal
with it.