Vacuum Advance Question

Ok. Lemmie see if I got this right. It will IDLE ok with the vacuum can hooked up to ported vacuum. It will not run with it on manifold vacuum.

With it on ported vacuum, when you give it throttle, it sputters and dies.

"I" would look in the distributor for something that shorts to ground when the vacuum canister moves the breaker plate. JMO.