Ls-V, obd1, eg hatch.

car idled fine last week (800-900). Within a 4 day span: the car gets tuned on dyno (smooth tune, no hiccups). After tune, noticed the car revving up to 3k on cold start-up (in the past didn't go as high). but goes down to reg idle.
Car also gets valve adjusted, re-thread of cam bolts that were stripped (maybe a little shavings flew in the head) & new oil, car idles fine, still revvs high on startup.

Car is raced (engine warm, new oil). car does fine. on 2nd pass, cars idles at 2,500 rshared_pm. for example, after i wrote this 1st post, went back to the car, started it and it revved to 5k directly, stayed there for 10s and then went down to 2-1,5k idle! Why does it rev that high on start-uP!?

1st FIX: Since then car will not go lower than 2,5k at idle.
With the help of other members, we were able to get the car to rev to 1500 on idle, still high, but driveable!.

However, on startup, car revs to 4,5-5k rshared_pm... (a little scary). then after a few minutes, as engine warms, car goes back to 1,500 idle.

Diagnostic that were done:
- NO vacuum leak
- changed IACV valve to OEM new one -> NO CHANGE IN IDLE
- TPS sensor within normal limits.

Sooooooo, does anyone have any idea?

The only thing i can think of is, for whatever reason, wiring?
I noticed that on the old and new IACV, if I unplug it, it does not seem to make a difference. Idle is the same... What could that mean?

anyone else have any thoughts? this is driving me crazy?!

UPDATE #1 - ran car from clearwater to tpa. When a/c on, engine idles to 1k. except when fan kicks on where it revs back to 1,5k for a couple of seconds. Left the car for about 30mn in the sun at parking lot, a/c was on when car shut was shut down. Started the car up (a/c on) and the car rev'ed up and down really quickly from 1,5 to 2,3 continously... until I shut off the a/c and idle dropped to 800-900! ( I was liek NICE It's back to normal!!) A/c still off, I go, idle is back to normal for a couple minutes. I put the a/c back on, idle still in normal range (around 1k). Turn a/c off at next light, idle is back to 1,5k... Dang! False hope!...

UPDATE #2 - Car is resting for the next 2 hours. Going to disconnect the battery. WIll see how car does when i head back home. well that didn't do crap!
Car still idles to 5k on cold startup and goes back to 1500 when warm.