Well, cleaning the MAF and UIM + PCM reset did not solve the problem. I do notice maybe a little more responsiveness and power in the higher rpm range, but still have the bad stumble in the low to 2K rpm range when accelerating. I cleaned the MAF thoroughly with 100% ethanol, I also noticed removing the electrical connection for the MAF while the engine is running appeared to make no difference at all positive or negative.
I guess the next step is to replace the plug wires one at a time and see if one of them is the problem. The strange thing is I changed the wires/plugs a couple of months ago when the problem showed up. I guess it is possible I replaced an old bad wire with a new bad one, esp if the Ford Perf wires have questionable Quality. I thought they seemed solid, thick and well put together. I think when I got the set of wires on now, i finally threw away two odl wire sets, hopefully i kept at least one...
