Connecting 'vacuum amplifier' causes hesitation off idle

Venturi vacuum
This port is above the butterflies and protrudes into the venturi, hence its name.Sometimes venturi vacuum is used to trigger a vacuum relay which then opens a larger passage underneath the butterflies. The important thing is that the canister should only be evacuated with a good amount of throttle opening, and absolutely not,at idle, where it will cause idling issues.The relay valve on later canisters was in the top of the canister. I can't recall what year they started that, but it was quite early.
This system operates independently of the EGR system, and there should be no interconnecting of the systems.