My A/C vents close as soon as the Boost kicks in. I can tell some one has messed with the Vacuum system and I have tried trial and error to get everything working again with no sucess. I have searched for a vacuum diagram but nothing matches. Does anyone have a diagram for a vacuum sysytem on a turbo 1979 280Z?

 

Welcome to ZDriver!

I'm kinda confused though... there was no 280Z in 1979, it was a 280ZX (280Z's ended in 78), and there was no turbo option until 1981.

So, which car do you have? And are you sure it's a turbocharged motor? Maybe a 79 280zx with an 81-83 turbo motor?

 

My Bad, This car was left to my wife. It is a 1982 280ZX Turbo

 

Ah, now that makes more sense.

Check out www.xenons130.com/reference to download the FSM which has all the vacuum diagrams you'd ever need.

But long story short, someone tied the vent vacuum line to the intake manifold instead of the vacuum pump / tank that's by the power steering pump. The pump turns on when you have the vents or cruise control going, and creates a constant vacuum.

 

Thanks Brother! I will give this a shot.