BMW Repair: whats wrong with my car!, peak summer season, fuel pumps

Question
during the peak summer season in my town I experience  "vapourlock" ..at least that is what folk suggest. I can drive my car for an extendes amount of time only to experience to what i would describe as "gas choking." If i pat the gas a few times when this first happens, i can conntinue a little while, but then it eventually dies out. I then have to wait for 30 to 40 mins. for it to start back up again. Before all this happens though, I hear a "humming" sound...this lets me know that at any given moment this will happen. I have a 1986 735 I vin# wbafh840xg0974121

Answer
What you should do is check to make sure that Both fuel pumps are working.I know you say Both? yes There is one in the fuel tank.Although it does run there are two fuel pumps.The one in the tank and an external one.Often the one in the tank fails,and the one in the tank is overlooked in diagnosis.It can be check by  removing it through the access cover in the trunk.The humming sound is a fuel pump and many times as well if you hear it very load its on its way out.Also replace your fuel filter because that too will cause your problems if it isn't changed regularly.