I've searched through the forums here and read just about every thread on the Integra's surging. I've tried pretty much all the solutions listed and nothing has helped.

I have a 99 GS-R that surges pretty bad when it's warm. All the threads here point to a failing IAC. I replaced mine with a new factory unit and it still surges, and no CELs. So out of curiosity I unplugged my new IAC(leaving it bolted in place) and plugged my old one in so I wouldn't get a CEL. I started the car and held the throttle till it warmed up, and it started surging when I released the throttle. So why would it be surging without the IAC actually moving and adjusting the engine speed? Would that kinda tell me I have a vacuum leak?