OH, YOU HAVE BYPASSED THE FUEL PUMP CONTROLER HAVENT YOU? (if in dought just earth the earth of the pump and it will get full voltage all the time. my 32 had a simalar problem. turns out it was the controler not the pump lol.
so just eath the negative pump wire and see how you go. and definatly get the shop to put a fuel pressure guage on it to see if its doing what i think its doing.