-Little Background, bought a 98 DX Hatch about 2-3 months ago from the original owner. Car ran very smooth with exception of the speedometer and tachometer not working and CV axles clicking.
-He only had receipts for timing belt, clutch, and “seals”. I’m assuming he didn’t do much maintenance but everything checked out.

-About two weeks I ran a can of spray Seafoam through the car to clean up any buildup.
-On Sunday driving home from work a CEL popped up for IACV.
-Cleaned TB and IACV, new TB gasket. When I started it back up Idle was surging between 1500-2000
-Car had absolutely 0 idle issues before I took off IACV and cleaned it.
-Went ahead and bought a new IACV and continuing to surge after installation
-Sprayed around TB for vacuum leak and nothing changed. -Put my finger over the hole in TB and nothing changed.
-I did not touch the idle screw and the cable does have about 1/2 if slack
-The butterfly valve is completely closed.
-Have yet to bleed coolant. but before I took anything off and engine was dead cold I checked coolant in the radiator and it was already topped off.

I did here a bit of a whistle while engine was surging around throttle body area.

Have yet to try..
Using multimeter on TPS
Spraying around IM.

Any other advice? I’ve read many of the forums regarding this issue but not much help.

Thank You