I read somewhere about being careful to note the IAC pintle position before removing one to be replaced, and manually moving the new one to the same position before installation.
My older IAC valve can be pushed-in or pulled-out; it takes some force, but it does move by hand. When I apply the same force to the newer one, it doesn't move at all.
I suspect that both of mine are ok, but I guess the real test would be to have one installed but disconnected and have another external one connected and turn the key to the ON position and see if the pintle on the connected one moves.
...It'* too bad that none of the typical scan tools can tell the ECM to test this kind of stuff like I've read that a Tech 1 can do...all of the common scan tools are only capable of reading and clearing codes and reading measured data.
'99 Bonneville SLE, white, 112,000 miles
'02 Park Avenue Ultra, white diamond pearl, 88,000 miles