Here goes again...

So I went to the car last night to grab something from the trunk, and noticed a small puddle of coolant that had run out from the right front tire area. I decided to leave it until this morning to investigate.
Upon opening the hood, I found the coolant to be coming from the overflow tank cap area. No other signs of fluid anywhere else. For good measure I checked inside the tank and found only bright green fluid, no brown sludge or anything, then I checked the oil dipstick, and found only bright clear oil, with no frothiness or green liquid.
Upon startup, she immediately went to a high (no tach, I'm guessing 3500) RPM and stayed steady there. I shut it down and checked the throttle cable. It was fine. Started again with the same result.
I did a lot of reading today and I haven't been able to find my exact scenario of course, but the closest I could get is suggesting that it could be the air mass meter failing. I did unplug the idle air control valve on top of the engine while it was running just to see what would happen, but nothing did. The temp needle has been fine and never fluctuated.
I am including a photo of a plug I disconnected under the intake manifold while it ran, and when I did, the engine came down to a normal idle and then about 10 seconds later it started running really rough, even backfired a few times. When I reconnected it, she shot right up to super rev again. Is this the air meter plug? I have not been able to find a photo of its location anywhere online including this site. Also my manual has not arrived yet.

I had trouble even figuring out what engine I actually have so I know what to look for. Vlvworld says (based on my VIN) that it's either a kjet or LH 1.0 and kjet.org says its a B21F-9 based on distributor type, ignition module location, etc...I'm inclined to go with the latter as its what everyone here seems to use. I don't really know what all those designations mean, I just want to know so I get the right info for diagnosis.

Idle control valve? Air mass meter? Thank you as always for any help and suggestions