Electric fuel pump timer or relay?

[Grit dog]

So maybe this should go in the efi or engine section but figured more views here….
Truck in sig. Carbureted engine with electric fuel pump and no option for a mechanical pump. (It was originally an EFI Vortec )
Currently ( no pun intended), electric fuel pump relay is triggered by a random ignition on hot lead. Works fine, except it’s not dummy proof in that if you sit with key on engine not running, fuel pump runs continuously.
Is there some sort of pressure sensor or timed relay to emulate efi engines where the fuel pump primes at key on and then does not run until cranking or running rpms are observed?
Or any suggestions on how to wire the fuel pump to run only while engine cranking or running?

 

[Bextreme04]

You could run the relay trigger wire through an engine oil pressure switch that will trigger on at 10psi or so. That means the pump would act just like a mechanical and only start pumping or running when the engine cranks enough to build oil pressure.

 

[Catbox]

You could run the relay trigger wire through an engine oil pressure switch that will trigger on at 10psi or so. That means the pump would act just like a mechanical and only start pumping or running when the engine cranks enough to build oil pressure.

This also works for you in case of an accident where the engine is stalled or disabled to stop the flow of fuel.

There is a relay that is built specifically for this instance, I just have to remember where I saw it....

 

[Catbox]

Here is a safety relay that I was thinking of, naturally it is from a VW supplier as that was where I was first thinking of putting a electric fuel pump....

Safety shut-off relay for electric fuel pumps :: Custom & Speed Parts (CSP)

For safety reasons, the fuel pump must not pump when the engine is at a standstill. What is no issue with a mechanical fuel pump becomes interesting when retrofitting to ...

www.csp-shop.com

 

[Grit dog]

Here is a safety relay that I was thinking of, naturally it is from a VW supplier as that was where I was first thinking of putting a electric fuel pump....

Safety shut-off relay for electric fuel pumps :: Custom & Speed Parts (CSP)

For safety reasons, the fuel pump must not pump when the engine is at a standstill. What is no issue with a mechanical fuel pump becomes interesting when retrofitting to ...

www.csp-shop.com

That's exactly what I was looking for, thank you.
Now to find one in stock and not for sale in Euros!
Thanks!

 

[Bextreme04]

That's exactly what I was looking for, thank you.
Now to find one in stock and not for sale in Euros!
Thanks!

This does the same thing.

https://www.amazon.com/dp/B00BNZ05JM/

 

[Catbox]

This does the same thing.

https://www.amazon.com/dp/B00BNZ05JM/

That one was the one I was going to purchase for my car.
But, I never did put the electric fuel pump on the thing....

 

[Dave M]

That's exactly what I was looking for, thank you.
Now to find one in stock and not for sale in Euros!
Thanks!

Here's what we use, great product.

LPG IN CARS - PEEL CP30 SAFETY SWITCH | eBay

PEEL CP 30 SAFETY SWITCH. Side of Coil. GAS+POS12V – Input 12 Volt power from Gas side of switch. This device is designed to turn off power to the Gas System when the engine stalls/turns off.

www.ebay.com

 

[Ellie Niner]

Quite a few years ago, I wired a seatbelt light/buzzer timer to the fuel pump relay to get a 5-7 second prime on a furrin car I used to own... an oil pressure switch controlled the pump after that. Looks like there are plenty of off the shelf solutions readily available today.

 

[Grit dog]

@Ellie Niner
That is an ingenious solution that sounds like it would work perfectly!

 

[Ellie Niner]

@Ellie Niner
That is an ingenious solution that sounds like it would work perfectly!

It did, though I gotta admit that it took me a fairly long time to come up with the idea and make a working circuit... then a bunch more to figure out that I just needed to add a diode to stop the fuel pump from backfeeding into the seatbelt light and lighting it up whenever the engine was running. Guess I *somehow* know more now than I did back in high school... but it probably helped my ass pass auto mechanics for that quarter since I skipped school about every other day back then.

 

[Grit dog]

Now if anyone knows of one of these timer relay contraptions like @Catbox posted, that is for sale in the US I’m all ears. Have done a little searching but to no avail yet.

 

[Catbox]

I would go with this one that @Bextreme04 posted....

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[yevgenievich]

I have used a tbi ecu before for fuel prime signal. It is more bulky, but was free. Oil pressure switch controlled it past that

 

[Grit dog]

I would go with this one that @Bextreme04 posted....

You must be registered for see images attach

Gosh, sorry I missed that. Yes that’s the ticket. Thank you gents