power problems. please help!!!

[hysteria]

my setup: straight t3, walbro pump, 12:1 rrfpr, open wastegate... very basic

my problem: when the boost gets to about 8 psi, usually about 2/3 of full throttle or a little more, the engine loses its power... you can hear it in the wastegate, as if one of the cylinders is crapping out or something like that. it makes a flapping or fluttering type of noise... like the wastegate opening and closing, or the rush of air stopping and going at a high rate, and the car just loses it's umph. as soon as you let off the throttle it'll gain it back but when you get to a certain part of the throttle it always loses its power. there are no other problems or symptoms.

my first thoughts: the engine has too much fuel. one of the cylinders is just blowing out the spark and not igniting properly... but i don't know really. does this sound like a super rich condition? or does this sound like some other problem? please help! thanks

[Florida240sx]

What is your spark plug gap??? If it isn't spark blowing out, thneit could be running too rich or too lean. Next thing it could be is timing.Spark gap should be around 30.

[KATwo40]

12:1??? That's pretty darned rich. I'd look at something around 6 or 8:1.

[j-z]

could be from running too rich. what do your plugs look like? are you running an EBC (electronic boost controller)?