53 Buick carb issue PLEASE HELP!!!!!

With the carb apart on a bench, you should be able to move that plunger up and down by hand (like I said, with some kind of liquid) and see where it's going. Either there's a bad seal between the plunger's leather seal and the wall of the pump well or it's being pumped back into the float bowl.

I once had an AFB Carter that had some bad pitting on the accelerator pump walls and could only get a small squirt at the end of the piston's stroke, like you mentioned.