Datsun Roadster Forum-311s.org

Can I get someone to look at this diagram for my electric fuel pump wire up? It makes sense in my head but would like a 2nd opinion.

To answer your next question, I'm going with an electric because I've been having trouble sourcing the rebuild kit for my mechanical. I figure wire up this and eventually rebuild the mechanical one so I have the option of either one.






Thanks!

Looks good to me. Remember that most electric fuel pums put out more pressure than our carbs can deal with so you'll have to add a pressure regulator.

Peace,
Pat

The one I have is 3 to 6 psi. I wondered about that but most that I've read haven't used a regulator.

Correction, it's a 2 to 3.5 psi

I used a fuel pump kit listed for the P510/710 Datsun sedans.
Fitted and worked fine.
The later mech. pumps that were fitted to the 810 etc were larger in diameter and not re-buildable.
And yes your schematic looks fine.
Here is an example of a safety switch: -






Summit Racing

I was actually using an inertia switch as the safety. I'll look into the 510 rebuild kit, thanks!

Good timing on this, I'm tackling the electric fuel pump wiring on my Red 67.5. Car came with the electric pump, but it's overfuelling the carbs, pretty much certain the pressure is too high. Will be getting an inline FPR.

I've removed the rat's nest of old hacked dash and engine bay wiring and installed good used harnesses from Ross @ Sports Imports. Now I need to connect up the fuel pump 12V to the harness, and this diagram looks like what I was planning to do. Not sure if any safeties have been installed (based on the fixes I've had to undo, I seriously doubt it) so I'll be setting up an oil pressure switch in the system.

My question: is there somewhere I can tap off the existing harness that will power the pump on ignition without using a separate switch?

I would use the coil feed wire which will be energised when the Ignition key is turned to ON or START.
A separate switch in series with the Ignition switch is not really essential.

Nissanman wrote: Sun Mar 07, 2021 2:23 am I would use the coil feed wire which will be energised when the Ignition key is turned to ON or START.
A separate switch in series with the Ignition switch is not really essential.

While a separate switch in series with IGN switch is not necessary, it might be useful if you ever experience an engine fire.
My brother had a fire start in the engine bay on a car equipped with an electric fuel pump, powered through the ignition switch.
The fire melted the wiring insulation and fused the pump's switched power wire to a constant power wire in the harness. He tried to turn off the ignition but to no avail. The fire burned the whole engine compartment with the electric fuel pump buzzing away, spraying fuel all over the fire. The battery was engulfed in flames so he was unable to disconnect the battery terminals.
Maybe a separate switch would have helped, but maybe not.
But it's something to think about when the SHTF, how does one cut all power to the vehicle short of a NHRA type kill switch like they use on drag race cars?