Fuel Bowl empties when stops!

once a siphon draws air, its action is done as it'll draw light air instead of lifting heavy fuel. BBD is a bottom feeder, inlet is low in the bowl so fuel could be drawn back into pump/tank. The pump should have 2-3 check valves in it depending on what model you have and you may in fact have a bad check valve, but I believe its heat related myself. My first 340 powered 65 had this issue. hard as hell to start hot and in the morning it took forever to start. installed a carter electric and it solved both problems. If I had a TQ, the bowls were leaking, if it was a AVS, the heat just boiled it right out. I just cant remember what carb I had on that car, IIRC it was an AVS as it still had 68 logs on it.