<VV> 140 vacuum advance?

[Ralphsebrell]

Guys/gals, I have an interesting problem. 
I just adjusted the timing and went on a test drive. Ran great! THEN I remembered I forgot the vac advance hose. Reinstalled the hose, I drove more. Same old problem. 
Removed and plugged the hose, Ran OK
The vac advance does move when I blip the throttle.


What is the problem? On slowly cruising main drag, light load, light pedal, the car wants to "Bump" a little. As the season goes on the bump  i will increase in intensity. 
Points, Condenser, wires all new.


My initials are not LC/LC so I need your suggestions.


Ralph
140/4 sp