Uploaded March 2026 | Updated September 2026, 2 weeks ago
This video documents me struggling to fix the fuel pressure on my 1971 Cutlass's relatively new in-tank EFI fuel pump. You'll see me first re-plumb the fuel system by moving the Holley Billet Fuel Pressure Regulator 12-880 from before the injectors to moving it after the injectors. I then find a bad crimp connector in the 30 Amp connector to the fuel pump. I then replaced about 6 feet of 14 AWG wire to the fuel pump with 10 AWG, and I replaced the 12 AWG wire from the battery to the fuel pump relay with 10AWG. The electrical improvements did reduce the volatge drop to the fuel pump from about .8v to less than 1/2 volt, but they did not fix the dropping fuel pressure issue. I then found that the AEM fuel pump that only had about 5 hours of use on it was mounted too close to the fuel tank floor, so I raised it, as well as installed larger wire through the Holley fuel pump hanger. It STILL dropped fuel pressure. Lastly, I replaced the new AEM pump with a Summit Racing 320 lph fuel pump. THIS finally fixed it. The whole time I was chasing a bad new fuel pump.
Parts used:
Holley Terminator X Max Stealth EFI 550-1013
Holley Oldsmobile Dual Sync distributor 565-206
Holley Sniper Retrofit In-Tank Fuel Pump Assembly 19-350
Holley Sniper EFI HyperSpark 2 CD Ignition Boxes 556-154
Holley Sniper EFI HyperSpark Ignition Coils 556-152
Summit Racing™ High-Flow In-Tank Electric Fuel Pumps SUM-250114
Holley Replacement Pressure Transducers 554-102
This video documents me struggling to fix the fuel pressure on my 1971 Cutlass's relatively new in-tank EFI fuel pump. You'll see me first re-plumb the fuel system by moving the Holley Billet Fuel Pressure Regulator 12-880 from before the injectors to moving it after the injectors. I then find a bad crimp connector in the 30 Amp connector to the fuel pump. I then replaced about 6 feet of 14 AWG wire to the fuel pump with 10 AWG, and I replaced the 12 AWG wire from the battery to the fuel pump relay with 10AWG. The electrical improvements did reduce the volatge drop to the fuel pump from about .8v to less than 1/2 volt, but they did not fix the dropping fuel pressure issue. I then found that the AEM fuel pump that only had about 5 hours of use on it was mounted too close to the fuel tank floor, so I raised it, as well as installed larger wire through the Holley fuel pump hanger. It STILL dropped fuel pressure. Lastly, I replaced the new AEM pump with a Summit Racing 320 lph fuel pump. THIS finally fixed it. The whole time I was chasing a bad new fuel pump.
Parts used:
Holley Terminator X Max Stealth EFI 550-1013
Holley Oldsmobile Dual Sync distributor 565-206
Holley Sniper Retrofit In-Tank Fuel Pump Assembly 19-350
Holley Sniper EFI HyperSpark 2 CD Ignition Boxes 556-154
Holley Sniper EFI HyperSpark Ignition Coils 556-152
Summit Racing™ High-Flow In-Tank Electric Fuel Pumps SUM-250114
Holley Replacement Pressure Transducers 554-102
