Honda Repair: 2004 civic si, coolant system, k20a3

Question
I have a 2004 civic si which has a k20a3 with 87k miles. My question is this, the car sat for almost 2 years without being started (I am ashamed to say) at all. Well we finally got the car going and as soon as we start the car it idled fine for a minute or two...then starts having a idle issue. Right about the time it warms up it starts jumping idle. It fluctuated from about 750-800rpm (which was usual for my car) to 1500-2000rpm. The car drives fine. You can put it in gear and take off no problem, under acceleration the car runs like a dream. Once you take it out of gear it begins to rev funny...also once the car gets hot the idle will hold at 2000rpm and makes driving in parking lots/making low speed turns very uncomfortable because at low speeds with the idle that high the becomes very jerky coasting in gear near or below 2k. I took apart the throttle body and the iacv then cleaned them both. The throttle body was dirty and gunked up. I used break cleaner in both careful not to wet the sensor. I also pulled the ecu fuse as I took apart and cleaned everything. I back it all back together and started it. It idled fine for a good period of time and to no avail it started idling hard again...I read about a idle adjust screw...and about a iac block plate which I'm scared to try...please help honda gods.

Answer
Albert, I believe the problem resides in the coolant system. You should bleed the coolant system. Or completely replace and flush the coolant then bleed the system. This is a common problem that occurs after a car has been sitting for a long time. Start here.