ok i mite just be dumb but that is the lil lever under the dash attached to the lower dash panel that two vacuum lines hook too

What year & model?

The OP has a 280ZX 2+2.

The FSM at XenonS130.com might shed some light.

That is were you hookup a ready whip cream can for a nos boost.

Just like in fast and furious.

Never mind. I thought I had translated the OP's message, but realized I don't have a clue what he's talking about.

Edited February 7, 201214 yr by Zed Head

It's the vacuum control knob. When the A/C is on or in the vent position, when it's open you have 85% air flow to the upper vents and 15% to the floor and when it's closed you have 100% to the upper vents and none to the floor. When the heater is on it has no effect.

Edited February 7, 201214 yr by sblake01

oh ok thank u i never used the A/C so maybe thats y i couldnt figure it out but thanks