4g starting air valve
 

I want to know if the starting air valve really does anything. I'm sure it probablly does up north where it is cold, but here in florida I don't think it does. Anyway this past weekend we were working on the engine cleaning up a few things and when I took the cover off of the air valve the damn spring went flying somewhere. Well we couldn't find it. I've been looking for replacement parts and can't find any. Is this valve really needed? And what is the whole purpose of this valve?