UPDATE engine dies when braking hard

I just have determined the problem lies in the accelerator pumps circuit. I had them adjusted per Holley's instructions, with a little pre-load, so the action is immediate. The problem was, when the brakes are on hard, the throttle linkage is tweaked enough to give a squirt of gas into the closed carb venturies. I tightened up on the acc. pump screw slightly, which gives a little clearance before the acc. pump is activated. This one about drove me off the deep end.
thanks for all the help,

Z. Ray