What is it?
 

And what does it do? I have them on my 86 (and on the 93 I imagine) and they are just hanging. Obviously it clamps onto something but where? I can guess the metal part keeps the line connected but what is the hanging part? And what are the plastic rings that are on the hose?

They look like the fuel lines. Look the same as the fuel lines on newer Ford CVPI's.

Maybe Oil cooler lines if not fuel lines?

Supply and return fuel lines for EFI cars. The black metal clips are a safety for the connections, the black nylon zip clamp that goes around line is to keep the clip with the line (many pop open from heat and movement - like yours are) and the white star washer items below the clip was used on assembly line for some reason unknown to me, but every EFI 5.0 has this unless removed by PO.

what he said....

So the black plastic clips are just to hold the metal clips if they pop out?

Yes. And once you take the metal clips off, you need a semi-special clip that releases the two hoses from each other.

The black plastic thingy is just a "tether" to keep the metal clip from getting lost.

On the 86 Idaho car it was a huge chore getting the fuel lines apart due to the fact I don't believe they had ever been apart before. I will be unplugging the fuel lines on the 87 today, hopefully they will come apart with less work.

I know what the lines are and how to disconnect them :yes: I just think its a lot of engineering to save a $3 part. It makes more sense that these things are put on the 2 lines at the assembly line to remind the installer to put on the clips so the line doesn't come apart. After that it serves no real purpose as the metal clip is holding the coupling together. Thanks for the responses.

also used for a/c connections