High/Low Idle after throttle body spacer install

I have a 95' Honda Civic 1.6ltr Vtec. As of yesterday I had NO PROBLEMs with it. It ran awesome. I installed a throttle body spacer (simple bolt off bolt on, no mods at all) Now my idle bounces from 1000 to ~1700 every second. I removed the spacer and put car back to original configuration and still the problem exists.
I have removed and cleaned the the IACV and the fast idle valve. Nothing helps. I have tapped on the IACV while it was running and there was no change in the idle. I measured resistance on the valve and i got 12 Ohms. Any ideas guys?

I have 93 accord lx 2.2. Never been modified & i have same problem. I am also looking for suggestions. Can any one help.

most of the time its a coolant issue of some sort.. there is a set screw on the top of throttle body, if its out to far it will idle that way.try screwing it in..