I've been trying to diagnose a raw fuel smell in the engine
compartment of my 1998 V6 Accord. While removing the intake air
plenum, I was planning to replace all the vacuum hoses, including
those that go to the FIAC valve. Unfortunately, one of the valve
stems crumbled, so I have a new unit on order. But...

I'm hoping someone can explain to me the exact workings of this
valve. I see it takes fresh air in and places it into both sides of
the engine. But the top hose that goes to the TB...Is that a thermal
valve? Basically I'm looking for a good explanation of this part, and
I have not been able to locate one on-line thus far. I'm really
curious what the hose from the TB does exactly.

Thanks in advance,
RC