I would be more worried about the engine running rough and burning valves then sucking crap into the engine.

It is an "idle up" valve for when the PS is working hard like at lock so the engine will not die. I found where the two lines go into the intake. I removed one and looped the other into it place. As far as a plug, I had to plug off the valve hole. I tried the RTV but mine was leaking fluid so I removed it, broke the plastic off, and brazed up the hole. If you do not have access to a find a metric thread brass plug for it. Do not try a metric bolt, it is a metric tapered pipe thread.