72 MGB-carbs, HIF type

["Dan Dougherty Sr." <globalrc@mindspring.com>]

The patient is a 72 MGB with HIF carbs, most of the pollution is disabled,
carbs rebuilt. Runs great, idles all day at a steady pace.....unless you
drop the revs quickly. THE IT DIES....like when you come to a stop. Restarts
easily. Manifold vacuum fluctuates on a gauge. No vacuum leaks anywhere I
can detect....been all over with spray. Any ideas? This one is bugging me.
Yes, we soldered the butterflys. Dan