ImportLuv, your throttle plate problem is a variation on the IACV thing that I mentioned. The throttle plate on a normal swap should be closed super tight. So tight, infact, that it's water tight (tested with actual water!). You could have simply adjusted the set screw on the IACV, which lets air around the plate (through that nearby 5/8" hose). Again, I don't think that improperly set idle adjustments are the cause, but merely exaggerate the actual problem.