I THINK i posted this in the newb section as well, but im not sure (dial up is gay)

this goes on the top/center of the gas tank and has a hose connected to it. I snapped off the part that goes in to the hose (genius ^_^)

I want to know what it is, so i can get a new one. any info (name, part#) would be awesome. also, wtf is this thing for, do i even need it?

 

that is the vent that goes to the charcole canister. if you dont have emissions or you dont need emissions in the state that your in then you dont need it. even then if you do have emissions they will never find that that is broken but you may loose fuel. but as for what is is named i dont know. mabey check the fsm for emission related stuff. just my 2 cents

 

Fuel vapor valve? From your description and jpg and 1990 parts fiche, this is what I came up with. See attachment.

 

. and http://www.cochran-racing.com/FSM/index.html