I have a 1956 Thunderbird with a 312 and manual transmission. I have a problem with the mechanical fuel pump in that when climbing a steep hill the car runs out of gas unless I turn on the auxiliary electric fuel pump. To try and fix the problem I rebuilt an original AC mechanical fuel pump with a kit from Then And Now. Unfortunately that did not fix the problem. So I pressure tested and flow tested the rebuilt pump. It passed the pressure test but on the flow test it only produced a 1/2 pint of fuel in 30 seconds rather than the 1 pint called for in the shop manual.
To make sure that the problem was not in the input line from the tank, I bypassed the mechanical pump and ran the input line directly to the carb so that I could run the car with just the electric pump. I then ran an independent input line from a free standing gas can to the mechanical pump and ran an output line from the mechanical pump to a container. I started the car but the mechanical pump still only produced 1/2 pint in 30 seconds.
Does anyone have any suggestions as to why the mechanical pump is not producing an adequate flow of fuel? Did I miss something in the rebuild?
Thanks.
Jim Yergin