nassau joe

well, i have been trying to figure out this surging sort of thing out now for some time. It acts like this: cruise at a steady rpm and the car will suddenly speed up as it has found new life and power, then the reins are pulled back once again. I have thought, well, its down on power about 50hp, so i did a compression test. all is fine. had 38lb white tops, thought ill try new injectors, so today, new svo42's went in. still there. I am asking, what is it? do the coils go in and out, maybe one going bad, i do not know. The motor is a 422 iron block, lsx90, nw90 tb, kooks, veraram, you name it. im open to any suggestion. thanks, joe