Tank ventilation routing (1 Viewer)

[Slow Poke]

After replacing my fuel tank I’m unsure about where to connect all the hoses. Specifically, the hose from the charcoal canister to the VCV. I have a 1977 and it doesn’t match the schematics that I’ve found that all seem to have a vacuum controlled unit. Mine has an electrical connection and 3 ports. The VCV is closed when the engine is running or not. Does it need vacuum to open?

 

[Slow Poke]

I found this diagram. The VCV has one larger nipple that is for the hose from the carbon canister. The smaller ones are for the Throttle Positioner and the intake manifold vacuum. I’m not sure if it’s working or not because I don’t really know how to test it. The truck seems to be unaffected so perhaps it was all for nothing anyway