240 Help. Mystery part fell from volvo

Hi, I was replacing the injector seals on my 244 the other day and I heard something fall through the engine to the ground while I was moving the fuel rail. Underneath, all I could find was this brass ring:




Does anybody have any clue what this is? I put everything back together with no apparent missing pieces, and the car drives perfectly fine. Maybe it was just sitting there on the engine and unrelated?

mmm, no pic for me, but are your grounds on the rail still there? under the bolts that hold the rail to the intake manifold

edit, nvm. I see you say runs fine.

The turbo hard lines use a brass ring for a gasket is all I can think of.

Fuel filter also uses those same kind of seals, if it's under the hood, someone probably dropped it while changing the filter.

Whoops sorry, I had email alerts off. The grounds are all there, my car is an NA, and the fuel filter is the kind that lives near the rear axle. I guess it was probably just sitting there when I knocked it.