Do I really CUT THE ORANGE wire? (Fuel pump relay with Terminator)

[Windsorpower]

Do I really CUT THE ORANGE wire near the back of the fuse panel?!!!!? Seems like I’ve seen a thread where a seriously irritated builder stated that the FFR manual was very misleading and that he never should’ve cut that wire. I think I should take the green fuel pump wire from the Holley harness and splice it to the orange wire in the RF “coil/efi/tach” bundle in the RF harness? But I’m no engineer…any advice? Thanks in advance

[michael everson]

You can use the fuel pump wiring as is and leave the holley stuff out of it completely. Or splice the green wire into the RF harness fuel pump wiring by cutting the small red or orange wire going to the fuel pump relay. They change the color but it will be the small non black wire.
Mike

[MB750]

I'm curious, but why does any EFI system feel the need to control the fuel pump? I mean, as long as there's 40 psi (or there abouts) why should the ECM care?

This goes back to hearing the fuel pump run for a few seconds at ignition, then shutting off. I never understood why it shuts off only to start back up as soon as you start cranking the engine over.

[weendoggy]

I'm curious, but why does any EFI system feel the need to control the fuel pump? I mean, as long as there's 40 psi (or there abouts) why should the ECM care?

This goes back to hearing the fuel pump run for a few seconds at ignition, then shutting off. I never understood why it shuts off only to start back up as soon as you start cranking the engine over.

Pretty much a safety factor. If the engine stops, the FP stops. If you wire it separately, engine quits, pump runs. Pump runs initially to insure fuel pressure present, then relies on cranking speed to keep it going. Otherwise, the pump runs all the time the key is on.

[Papa]

Holley EFI systems include their own relay for the fuel pump power. I didn't use the Ron Francis relay at all. I de-pinned the fuel pump wire from the connector where the rear harness gets plugged into the main harness and connected the Holley fuel pump wire to the rear harness fuel pump wire. Keep in mind that this makes the inertia switch useless if left where the manual has it installed. You can simply wire it into the fuel pump ground instead.

[Dgc333]

Holley EFI systems include their own relay for the fuel pump power. I didn't use the Ron Francis relay at all. I de-pinned the fuel pump wire from the connector where the rear harness gets plugged into the main harness and connected the Holley fuel pump wire to the rear harness fuel pump wire. Keep in mind that this makes the inertia switch useless if left where the manual has it installed. You can simply wire it into the fuel pump ground instead.

Same here. I installed a Hemi in my 33. The EFI harness included all the wiring to run the fuel pump and starter motor. I pulled the fuel pump relay from the RF fuse panel and didn't use it and also didn't use the START wiring in the RF harness. I was told by the outfit that supplied the EFI harness I could wire in the inertia switch but it is redundant and just adds another point of failure.

FWIW, I wired the engine and did the first start with the RF harness still in the box.