Hi all! My name is Brian and this is my first post. I frequent the site often but usually can figure things out just reading what's here. However, the scenario I have is a bit different. I have a 1993 Ford F150 with the 5.0 (302) and recently took the motor out and had it built to a 347 stroker. I've got the motor back in everything is hooked up and it will turn over but only for a brief minute. I've found that the fuel pump is running when you turn the key to the on position and building the fuel pressure gauge up to about 4-5 pounds (through a Holley regulator) which is where I need it. However the pressure falls after it's running for a minute or so which tells me the fuel pump isn't running continuously like it should. I cut the EFI wiring harness and only used about 5 wires. Any thoughts out there?

Hi there! I have recently made some changes to me 1993 Ford F150. I pulled the 5.0 (302) and had it built out to a 347 Stroker. I removed all the emissions stuff and put the same motor (built up of course) back in, but with a carburetor. I kept the same fuel pumps (dual tanks), and most of the same wiring. I say most because I cut the wiring harness to the efi since I didn't use but about 6 of the 43 wires (those wires are numbered, and I believe it is Ford part #C101M. The harness has 43 wires and goes to the efi fuel rail). Therein lie the problem. I believe it may be in one of those wires, but when I turn the key over, I can hear the main fuel pump prime the carb and it shows about 4psi on the Holley regulator just as I want. However once I start the truck, the fuel pressure drops to zero as the truck is using the gas in the bowls of the carb from the initial prime. Bottom line is that the "low pressure" fuels pump(s) are not coming on and certainly not staying on. I hate to ask, but I need help on this one. I appreciate any help in advance! Sincerely, Brian

 

merged two threads

 

That mean that your low pressure fuel pumps are working, or is it a different circuit? I have dual tanks. Modified motor, still could use some help!