I dont see a switch at the firewall, but there is a connector
at the throttle cable where it goes through the firewall.

I see in the Vacuumdi.pdf file (Vacuum Lines "M")
that there's a "Throttle switch" clamped under the passenger end
of the fuel rail (Thats not a throttle position switch I'm sure)

I also see that the brake servo hose has an evap valve back to the
engine vacuum. Is the one way vacuum booster valve that little plastic
dodad where the hose hooks up to the booster.
How do you check all this stuff?

Thanks, Bill