IP Question
 

On my 77 N/A car there is a metal can on top of the IP. Looks like mabe a govenor, or advance?
Is this to be hooked up to vacuum? if so where? and constant vacuum, Like from VP, or changing from where?

I will get a photo later if needed. Car is at home, I am at work. :(

thanks

dome shaped thingy does not connect to anything it stays open like that.
I asked the same question with picture and that was the answer.

That's the "ADA".

It senses atmospheric pressure and reduces fuel in the IP as the pressure is reduced (when the vehicle climbs in altitude). The engine would smoke rather badly at 5000 feet without such a device.

That adds up now.
thanks