Connecting 'vacuum amplifier' causes hesitation off idle

Go back to the drawing, post#8. The canister port seems to be on the opposite side of the carb to the EGR/Amp ports. It's very important to get the right nipple. I believe the correct nipple has a very tiny orifice. As far as I recall there's only one like it. I may have been wrong about the venturi port on a slanty. The carb may be calibrated for a full-time draw from the canister. If/when you see that small-orifice nipple, and it fits the canister hose,plug it in. Mostly the nipples IIRC are different sizes, and that helps to settle the install.