Understanding SFT's

[tekrsq]

I have a 5 Star Tuning SCT X4 on my 99 5.4L. Normally, my STFT's stay between 0.95- 1.10 depending on temp and speed. Yesterday while at about 75mph (2100 ish rpm) it suddenly had episodes of losing power for a brief second, then pick up normal again. When it would do this,my STFT on both banks were at 0.75, then return to normal. I notice when i backed my speeds down to 65 mph, it ran fine but the trims were jumping from 0.75 -0.95. Running it this morning, it did the same thing but i noticed if i accelerated hard, both banks would drop to 0.75and staythere until i let off the throttle. Has that happened to anyone before, or any ideas what's happening?

 

[tekrsq]

I guess I should mention that the fuel pressure regulator, fuel filter and pump are about 10, 000 miles old, the COPs and plugs about 30,000, and the injectors are about less than 10,000 along with a reman engine. It runs great, except when it suddenly starts losing power.