The Ford Barn

lilith54 · 04-01-2025, 01:23 PM

I bought a 54 ford customline with a 256 y block. i was told by the previous owner it had some 55 f-100 parts on the engine rebuild. i don't fully know what all was modded and would like to better understand it, and i have very basic mechanical skills (using this car to learn on). This car has been a daily driver for me.

Anyways, the mechanical fuel pump that was on it when purchased a year ago was a delphi mf0063 mechanical pump. it failed the day i got the car while going down the highway, carb was recently rebuilt before i bought it also. I swapped out that pump for another one just like it. fast forward a year and 2k miles later, and it may be failing again.

I ran the tank a lil low and while coming home one night on the highway, it died. i put a few gallons of gas in it, and was able to drive it home, but it would die every mile or so. the car wouldnt start unless i let it sit for about 5 minutes, and then it would die again.

now, i checked and replaced the fuel filter. still issues.

i checked the PSI coming off the fuel pump and it is 7 psi (seems a lil high).

the car will idle and run in the garage, but if i try to drive around the block it will die again, and then fire back up a few mins later.

next steps i plan to do are check the carb for settlement or the jet, or replace with another fuel pump. is it possible this pump is still failing even though its showing 7 psi? should i be using a different pump? it has a 12 volt system, should i switch to electric on the pump? is there anything electrical i should be checking or is this likely a fuel delivery problem. if it is a vapor lock, why would it drive fine for 2k miles and now all of a sudden be an issue?

sorry if this is a very newbie question, because i will admit i dont know much. just trying to figure out if i should replace the pump with something else, or continue diagnosing in other ways.

04-01-2025, 01:23 PM	#1
lilith54 Junior Member Join Date: Apr 2025 Posts: 12	256 y block 54 customline FUEL PUMP I bought a 54 ford customline with a 256 y block. i was told by the previous owner it had some 55 f-100 parts on the engine rebuild. i don't fully know what all was modded and would like to better understand it, and i have very basic mechanical skills (using this car to learn on). This car has been a daily driver for me. Anyways, the mechanical fuel pump that was on it when purchased a year ago was a delphi mf0063 mechanical pump. it failed the day i got the car while going down the highway, carb was recently rebuilt before i bought it also. I swapped out that pump for another one just like it. fast forward a year and 2k miles later, and it may be failing again. I ran the tank a lil low and while coming home one night on the highway, it died. i put a few gallons of gas in it, and was able to drive it home, but it would die every mile or so. the car wouldnt start unless i let it sit for about 5 minutes, and then it would die again. now, i checked and replaced the fuel filter. still issues. i checked the PSI coming off the fuel pump and it is 7 psi (seems a lil high). the car will idle and run in the garage, but if i try to drive around the block it will die again, and then fire back up a few mins later. next steps i plan to do are check the carb for settlement or the jet, or replace with another fuel pump. is it possible this pump is still failing even though its showing 7 psi? should i be using a different pump? it has a 12 volt system, should i switch to electric on the pump? is there anything electrical i should be checking or is this likely a fuel delivery problem. if it is a vapor lock, why would it drive fine for 2k miles and now all of a sudden be an issue? sorry if this is a very newbie question, because i will admit i dont know much. just trying to figure out if i should replace the pump with something else, or continue diagnosing in other ways.