Si, Z6 problem

[viridion]

at first i thought it was limp mode, because at it feels like it stops the spark at 3k in first gear, but the more i drove it and tried different things i'm not sure what it is now.. alright, if i am running 1/4 throttle the car runs fine, idles and starts fine, no CEL..no code, i changed the fuel filter, i tried adjusting the timing, new plugs/wires/cap/rotor but the car still will just lose all power when i'm over 1/4 throttle under load. it revs fine up to redline but as soon as it's under load, anythign over 1/4 throttle just dies, i can cruise just fine down the road at 1/4 throttle all the way to 5th so it runs and drives still.. any thoughts/ideas as to what to try next?

it's a 94 del sol si.. all stock absolutely no mods.