CIS hose function?
 

Can anyone tell me the purpose of the ~.5" rubber line that runs from the CIS system (near the frequency valve) all the way to a hard fitting at the entrance to the tunnel where the other fuel lines go? It attaches with hose clamps at both ends.

I don't think it is a high-pressure fuel line, as those are hard lines in the car. Does the frequency valve bleed off fuel pressure and then it just returns to the fuel tank at low pressure?

I just replaced one of the hard lines, and this hose is looking kind of rough, so I want to make sure I get an appropriate replacement hose. All the parts place has is radiator hose in that size.

Thanks,

Olivier

Vacuum line for the brake booster?

That's a good possibility, it is about the same size as those lines on more traditional layouts. I had not considered that.

It does lead to the same tee that connects to the side of the airbox, so it must be a large vacuum line.