Hello All - this is a new thread following up on my other older posts.
I have good news but questions still remain.

The Good News :
I have partially corrected my throttle adjustment / IAC function.

Ok, as far as the IAC in relation to the throttle adjustment, Lucid was right. However some interesting questions still remain, more on that after I explain my lastest information that hopefully will help others out there struggling with throttle adjustment.

As I posted before, I did correctly set all the adjustments on the throttle according to the book using feeler gauges. So why did my engine/RPM not respond at all when I pinched off the hose to the IAC? Simple short answer, my throttle plate was sitting open, so air was coming from an "open throttle" when sitting at idle.

After setting everything correctly, while lastly tightening the two small allen bolts on the TPS, I noticed the throttle spindle rotate slightly clockwise (open throttle) just as I locked it down. I did not notice this before because:
1. I was holding the TPS firmly so itself would not rotate after I made the "click adjustment".
2. My .15 feeler gauge was in place (sitting between the idle adjustment screw and the lever) as I tightened the TPS fixing bolts.
3. Because there is just an ever so slight bit of slack in the throttle linkage (link rod adjustment) the spindle can rotate pushing up that bit of slack on the rod linkage before the throttle lever comes off the adjustment screw or in my case the inserted feeler gauge. I'm talking SLIGHT, those little ball joints are not that precise ! I noticed this while I was fixing the allen bolts on the TPS and looking very intently/closely at the spindle itself at the spring/fixing nut end.
4. Because I had cleaned the throttle body and adjusted the TPS and idle screw several times, it was a compounded mis-adjustment that I was not aware of all those times. That 1/4 turn adjustment after contact with the throttle lever was no longer set correctly because of the link rod setup (even with a 2.5 feeler at the pully stop). So the idle adjustment screw was holding the throttle open more than I thought just as Lucid suspected.
5. So it wasn't necessarily that one-time small rotation of the spindle as I tightened it down that caused the problem, it was more likely a result of a number of these adjustments that kept moving the plate more open every time.

The solution:
I unhooked the linkage and ran "out/down" the idle adjustment screw all the way off to allow the throttle plate to bind in the closed throttle position. Ran up the idle adjustment screw to contact the lever then the 1/4 turn and locked it down. Re-adjusted the link rod and TPS with the feeler gauges again but this time.....I had to hold the spindle(not the nut or the lever itself,just the bit on the end) with a small crecent wrench while tightening down the TPS screws so that the spindle didn't turn in that final torque moment.

The first thing i thought of was the spindle was too far inserted into the TPS. I measured that with calipers and it was dead on at 22mm with clearance going into the TPS. My best guess is the "rim" or o-ring on the TPS inside face that mates with the bushing of the throttle spindle creates just a bit of friction and can cause it to move slightly as you tighten the TPS down. And because I had a feeler gauge in there and holding everything stationary I didn't really pay attention to that bit of rotation.

Lesson: Carefully watch your throttle spindle while tightening down the TPS. If it rotates , it throws all your careful adjustments off. If others have adjusted idle by moving the screw and re-setting the TPS over time, this adjustment could be "walked" off and you wouldn't even know it unless you back everything off and start from the beginning.

Results:
My idle is now reset back to a base starting place and my symptoms of the engine staying at high rpm while coasting at speed appears to have been corrected. More importantly and interestingly when I now clamp the IAC hose while at idle, the engine stalls almost immediately as it used too. Also the amount vacuum being pulled from the IAC is much increased with the throttle plate now in a more closed position. Where does the ECU receive this information to alter the IAC operation ? The MAP sensor ? Or was it just a lack of "mechanical" vacuum coming through the IAC because of the throttle plate allowing in more air causing lower pressure? I know it doesn't come from the TPS because, before, even with the throttle plate slightly open at idle, the switch could not click(on) until there is movement on the throttle spindle regardless of its static relationship to the spindle itself..

Conclusion and weirdness:
Now that the throttle is set at a base setup, I purchased a clamp on style digital induction tachometer. I wanted to check my rpm at idle now with the new base setup.
Here is the weird part . The brick seems to idle fine and not apparently low, on the cluster tach , the needle is about dead center between the 0 and 1000 rpm. If anything it bumps up just a bit higher than the middle once it's up to operating temp. When I clamped on the tach around the coil wire about in the middle it reads 380 RPM steady. Weird right. Then I rev the engine to what I would think would be about 2000RPM it increases but from 380 not what the cluster tach says.
I moved the clamp on tach to each spark wire it only reads a double digit number like 98 or 89 etc.

Finally, now my question is: If the meter is reading correctly and my idle is too low, how do I increase/adjust the idle now if what I set was by the book and having the throttle even slightly open at idle seems to cause problems with the IAC as it did before when I tightened the TPS.

Thanks for everyones time and hope this helps others.
Schumi 1