mat in tn Posted May 23 Share Posted May 23 We recently fought this same problem at our automotive repair shop. After looking over the wiring schematics and seeing that the 7.5 and 5.0 fuel system was wired almost identical led me to look up what a rear fuel pump for an 86 Ford F250 with a 5.0 looked like. And it was the one we needed! The Carquest part number was HS3496087. it may look like what you need but are you sure that it supplies the correct pressure? it may but try to be certain. the 86 5.0 used two/three pumps in series. a low pressure in the tank /tanks with a high pressure boost pump on the frame rail to achieve efi pressures. is the f250 still carbureted? if so, it may be the same pump Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 23 Share Posted May 23 it may look like what you need but are you sure that it supplies the correct pressure? it may but try to be certain. the 86 5.0 used two/three pumps in series. a low pressure in the tank /tanks with a high pressure boost pump on the frame rail to achieve efi pressures. is the f250 still carbureted? if so, it may be the same pump You're right Matt, but low pressure for EFI is still more than a 4180 can handle. The poster may have to do like Gary and replace the vapor separator up on top of the intake behind the coil with a return regulator set to 5psi. I'm sorry, but the exact Holley number that Gary used escapes me ATM. It's certainly posted in multiple threads.... Link to comment Share on other sites More sharing options...
85lebaront2 Posted May 23 Share Posted May 23 We recently fought this same problem at our automotive repair shop. After looking over the wiring schematics and seeing that the 7.5 and 5.0 fuel system was wired almost identical led me to look up what a rear fuel pump for an 86 Ford F250 with a 5.0 looked like. And it was the one we needed! The Carquest part number was HS3496087. I went through this when I first bought Darth, the front tank had a rusted through seam area and the rear tank pump was dead. Pep Boys had the only listing for the 460 W/hot fuel handling package. They are a centrifugal pump that delivers 5-7 psi according to what I have on AllData. Link to comment Share on other sites More sharing options...
mat in tn Posted May 23 Share Posted May 23 You're right Matt, but low pressure for EFI is still more than a 4180 can handle. The poster may have to do like Gary and replace the vapor separator up on top of the intake behind the coil with a return regulator set to 5psi. I'm sorry, but the exact Holley number that Gary used escapes me ATM. It's certainly posted in multiple threads.... true that adding a regulator can be a good safeguard. I have done both over the years. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 23 Share Posted May 23 true that adding a regulator can be a good safeguard. I have done both over the years. The 5.0 pump is too high a pressure and not nearly a gallon a minute, like the 460 spec. Link to comment Share on other sites More sharing options...
viven44 Posted May 23 Share Posted May 23 it may look like what you need but are you sure that it supplies the correct pressure? it may but try to be certain. the 86 5.0 used two/three pumps in series. a low pressure in the tank /tanks with a high pressure boost pump on the frame rail to achieve efi pressures. is the f250 still carbureted? if so, it may be the same pump I bet that 5.0 setup with 2 fuel pumps to boot would be right up Bradley's alley In that 2 fuel pump setup, if one of the pumps dies, its game over. If the low pressure pump dies, the high pressure pump will vapor lock the fuel on the suction side immediately. If the high pressure pump dies, obviously that is not going to work either. Why did they not just set the high pressure pump in the tank and call it a day like they did later in later years? Maybe they realized the vent (breathing) system in the bullnose truck tanks sucked big time. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 23 Share Posted May 23 I bet that 5.0 setup with 2 fuel pumps to boot would be right up Bradley's alley In that 2 fuel pump setup, if one of the pumps dies, its game over. If the low pressure pump dies, the high pressure pump will vapor lock the fuel on the suction side immediately. If the high pressure pump dies, obviously that is not going to work either. Why did they not just set the high pressure pump in the tank and call it a day like they did later in later years? Maybe they realized the vent (breathing) system in the bullnose truck tanks sucked big time. You answered your own question... Link to comment Share on other sites More sharing options...
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