alrighty so the motor in question is the d15b2
starts up fine, idles alright at first
running at normal rpm, drops down to like 250-500 ish for a few seconds, goes back up for a little while, drops for a few seconds, goes back up, drops, etc...
i can't accelerate unless i give it half throttle, any more causes it to bog out like it's being suffocated
is this the eacv? would anything else cause this screwy idle?

 

If it gets to operating temp, then drops to a low idle, but rises and falls, that's pretty much classic IACV. Clean it (super easy) and check it again. There's a DIY IACV cleaning in the DIY maintenance section.

 

IACV won't cause that failure to accelerate. You should check the TPS. If you're saying that it is OK up to half throttle but it doesn't like wide open throttle, it could be weak sparks or starving for fuel (clogged filter).

 

alright, so i'm gonna clean the iacv and then check out the fuel filter. it's funny though, low rpm WOT = no acceleration. if i shift a little later than i should, accelerates just fine. 5th gear at 80km WOT = no acceleration, 5th gear at 100km WOT = acceleration. as long as the RPM is higher than 2-2.5k (guessing, tachless at the moment), runs fine. it's like it suffocates at low rpm WOT.