Hello,
I'm looking at the QJ in my '66 Toronado. These don't have the conventional secondary pull-off. I always assumed that the arm/piston connected to the secondaries were exposed to engine vacuum, so it would function the same way.
Today, with the engine running, I pushed on the secondaries flap and there was no resistance other than the return spring, whereas with my later QJs, I would be fighting engine vacuum via the pull-off. Is this normal?
Thanks.

(photo from ebay)

 

That is normal for the 65/66 Quadrajets. This dampener system was then changed to the vacuum release and the spring tension.

 

Thank you.