Valve cover differences and carbon canister removal

[Huw Powell]

> > I could do that with a check valve to keep it under
> > vacuum.
>
> Yes, that's what the factory does I believe.
>
> > So when does the Carbon Canister Valve decide
> > it should be open to let the fumes into the engine
> > anyways?
>
> Someone correct me if I'm wrong here, but I think it is a duty cycle device
> much like the ISV and it operates mostly when the engine is on decel or idle.

I never really knew what kind of car we were talking about here... as
Marc says, on the type 89 there is a frequency valve thing that ticks
away at idle.

on the type 85, typically, there is a vacuum actuated valve which
controls when the vent line is run to the canister.

there is a schematic of the '82, CIS (no E) system at the url below, I
think you can figure out when and how this system vents what to where...

--
Huw Powell

http://www.humanspeakers.com/audi/vacuum-system.htm

http://www.humanthoughts.org/