my idle started dipping about amonth ago out of nowhere

stock obd2b ecu bone stock rebuilt motor.
good compression good coil cap/rotor wires plugs
timing is good all sensors show good in scan gauge. no codes
new o2 sensor denso
valve adjustment recent.

dips to 500 right after start. then every time I get out of gear it dips and goes back to normal.
everywhere I look its jut bunch of people asking same question and every answer is guessing what it can be.

 

cleaned iacv and it got even worse.
does carb cleaner damage iacv in any way?
I used it many times and see people use it everywhere