IAC valve O-Ring?
 

Hi everyone, I'm the new guy. I'm attempting to resurrect a 2000 Montero Sport LS 3.0L. It idles awfully, up to 2k rpm at startup down to about 5 or 600 hundred, then it dies or remains at idle super roughly. I pulled the IAC valve in hope of cleaning it and the throttle body. When I did, I noticed the valve had no O-ring or any silicone at all. Would this not create a vacuum leak? Could it be that simple? Me and "simple" have never been on speaking terms, so I'm skeptical. Im a novice at this stuff so I thought I'd throw this out there to the more experienced. Thoughts anyone?