I have a jdm ae101 gze. Recently it started running rough. Feels like a misfiring, every once in a while it'll run normal for a few seconds then starts sputtering again. Checked all plugs and wires, checked timing, checked for vacuum leaks, will try cleaning coil packs and replacing wires, might be ecu but don't have a known working one available. Anything else I should check?

fuel pressure?

I'll add it to my list

what he said, i would look into the fueling system. example: fuel pump? injector resistor pack, fpr, injectors. especially the fuel pump relay, and the contacts.

after looking at those things, i would inspect the coil packs for leaking. also, numerous 4ag's ive had, if they get the slightest bit of moisture around the plug wires, whether at the coil, or in the plug valley, they will misfire, and act retarded. ive had 1 case where a plug wire had arc eroded inside the coil pack, where it wasnt getting a constant good connection.

check or vacuum leaks to the map sensor, example, if the ABV has a failing diaphram, this will cause a vacuum leak.

also, check to make sure your ignitor had a good ground. if the ignitor ground is shotty, it will cause some issues. the ignitor has to be grounded for for its operation.

Well hopefully in the next few days I'll get a chance to really tear into this, thanks!!

is it a misfire, like skipping a cylinder? or does it act like its starving and tries to cut off?

Like a misfire, it holds idle mostly, then the more gas you give it the more it rattles the car, I can still feel the SC kick in but it's only a slight power feeling, when idling downhill the car feels normal. Sometimes when I turn the car off and let it sit for a few minutes it will run better, as in it will have full power for longer spurts of time inbetween the sputtering.

does it sound like a wrx when it does this?

Yes it does, that exactly what I was thinking when it started, it sounds like a wrx

My GZE in Japan sounded like a Subie, but I'd assembled the engine with a rag in the #1 runner. Rag removed, problem solved.

I wish it was just a rag, my car just seems to be on the rag

Well finally found the culprit, FPR wasn't working properly. Second FPR I tried was even worse, my last FPR made everything alright, on the bright side, fuel injectors are clean, throttle body and iacv cleaned and AC idle up is finally hooked up. As far as functionality of everything, it all works now, now I need to make it pretty when I have time......