Originally Posted by crackedback
It's the point where it is supposed to start opening. They can be off a bit.

There is usually some lag between vacuum reading and observed AFR changes. Shouldn't be much though.


Starts closing, it’s open till the vacuum is less than the # , say 6.5, below it’s open, above closed, no middle ground. Nothing more than a on-off switch. The PV is a valve has no bering on how much fuel flows thru it, holes are bigger than the restriction.