what is this? I think I know.

[shmoky]

Is this a PCV valve? Looks like it may need replacing. lol


shmoky

[AriK]

Two way check valve. See the last few posts on this thread. There are plenty of threads on this subject.
http://www.fiatspider.com/f15/viewtopic.php?f=5&t=33949

[DieselSpider]

PCV valve goes between the intake and the valve cover to scavenge combustion gasses that make it past the piston rings and direct them back into the intake manifold to be burned and sent out through the exhaust system which is otherwise known as P(ositive) C(rankcase) V(entilation). The PCV valve shuts done its flow to prevent engine oil from getting sucked out of the crankcase when high intake vacuum levels are present. During times of heavy engine loads the intake vacuum is low so the valve stays open to collect the blow by that gets past the piston rings.

That valve in the picture is a flow limiting valve on the evap system to prevent a large flow in either direction from the evap canister. When it fails you can have problems such as gasoline in your engine oil or excess fuel tank pressure overwhelming the float in the carb.