surging idle 1992 honda accord ex 2.2l

I was told that the EACV and/or FIV could be dirty.I've tried to clean
these parts and no luck. The idle still surges from 1100 to 1600 rpms.
The idle is fine when it starts up. Starts at about 2000rpms. It
seems like it sticks a little though when I slightly throttle it. When
it is fully warmed up, the idle problem starts. If I pull the
connector on the EACV when the car is warmed up the idle doesn't drop
at all. It surges even faster from 1100 to 1300 rpms. If I disconnect
it when its cold then it drops but nowhere near the normal 500 to
600rpm range. I sprayed throttle cleaner inside the EACV through the
screen and the other opening. I replaced the FIV with a new part. I
ordered a new EACV. If that doesn't work where do I look to solve this
problem. Also the idle never goes down below 1000 rpms. I have heard
that maybe the idle screw needs to be adjusted but the screw has the
head in the shape of a pentagon. I have not been able to find an
autoparts store that has ever heard of a tool or bit with the head of a
pentagon. Some dont even know that it is a five sided shape. They
keep showing me hex bits. I tried search for a vacuum leak but
nothing. The only other things left are checking the EGR valve. Air
boost valve, and the TW sensor. Oh, I have also bleed the coolant
thoroughly. Any suggestions would be greatly appreciated. You cant
imagine how many mechanics I ve stumped with this. Some honda
techs!?!?!?

thank you