I did some searching and wasn't able to find much. Today while upgrading the injectors in my 1.6L Miata when I took the part of the IAC off that bolts to the intake manifold I noticed that it has a gasket in there that is blocking the entire passage off to the IM.

Trying to figure out why it would be blocked off and if I should restore it back to how it should be. Car is currently running on a DIY MS3 and idles ok for the most part.

 

It's a fast idle valve that's only used when the car is cold. If it's blocked off then someone thought it might help the car idle, I'm guessing.