Swirl pot second fuel pump wiring.

[David-1dyf3]

Hi guys,

So I've finished my swirl pot (internal pump of swirl pot), fuel lines, fpr etc.

Wired up my 4 pin relay

1. 30 to battery
2. 87 to fuel pump
3. 85 to ground to chassis.

Now the #86 signal wire for triggering the second pump. I've tried to look/find diagrams for the trigger/signal wire with no certainty. Can anyone confirm what I tap into?
Would I just tap into the signal wire of the factory relay?

Also I'm running my oem fuel pump to supply the swirl pot. Does any wiring need changed, does this pump need to be constantly supplying the swirl pot with fuel to keep up?

Cause I was thinking if both pumps are being triggered by the same signal. Would my swirl pot in-tank pump (walbro 255) effectively make the swirl pot abit inefficient being say half full due to demand of the 255 being able to pump more?
Tried searching for my answers for while but my understanding of these points is where am at abit unclear.

Thanks.

[David-1dyf3]

Any help would be great👍

[Happy Jim]

1. Yes, but! Depends how your original signal wire is wired, if it’s switched +12V then it will work, if it’s switched -12V then it won’t (you’ll have to retire your relay to accept a switched ground to pin 86.

Can’t really answer the second question without knowing how flow/return lines are plumbed.
Jim

Edited by Happy Jim on Monday 13th July 21:57

[tapkaJohnD]

David-1dyf3 said:

Hi guys,

So I've finished my swirl pot (internal pump of swirl pot), fuel lines, fpr etc.

Wired up my 4 pin relay

1. 30 to battery
2. 87 to fuel pump
3. 85 to ground to chassis.

Now the #86 signal wire for triggering the second pump. I've tried to look/find diagrams for the trigger/signal wire with no certainty. Can anyone confirm what I tap into?
Would I just tap into the signal wire of the factory relay?

Also I'm running my oem fuel pump to supply the swirl pot. Does any wiring need changed, does this pump need to be constantly supplying the swirl pot with fuel to keep up?

Cause I was thinking if both pumps are being triggered by the same signal. Would my swirl pot in-tank pump (walbro 255) effectively make the swirl pot abit inefficient being say half full due to demand of the 255 being able to pump more?
Tried searching for my answers for while but my understanding of these points is where am at abit unclear.

Thanks.

If Q2 is, run the lifter pump to the swirl pot all the time? Yes.
The idea of a "swirl" pot is that the circular motion of the fuel in the container (it should have a circular profile) causes any bubbles to pass to the centre, where a return pipe to the tank gets rid if them. If you stop the lifter feed pump, then so will the swirl and the bubble could go anywhere.

John

[David-1dyf3]

Thanks mate for confirming 👍

An6 teflon Lines are plumbed up as -

- fuel tank supplying swirl pot.
- swirl pot supplying fuel rail.
- return from FPR back to swirl pot
- swirl pot over flow back to fuel tank. ( Would I be right in adding a restriction so the factory fuel pump has load? )

Cheers

[the_stoat]

I would not be using the OEM pump to feed the swirl pot, on the assumption your car has fuel injection, the feed to the swirl pot should be low pressure. More details on car etc would be useful to give definitive advice. I usually trigger the swirl pot pump from the high pressure pump feed which in turn is controlled by the ecu.

[David-1dyf3]

Ok, so what how could I wire to be constantly feeding from the lift pump?

It's a honda integra dc5, OEM pump flows 140- 150LPH. I thought the pressure would be low due to no load/ pressure regulator on the lift pump from solely supply swirl pot and back to fuel tank.

Or are you talking about the pump pressure to flow LPH?
I thought the OEM pump would be high pressure compared my walbro.

Thank for the info guy really helping 👍

[GreenV8S]

David-1dyf3 said:

Ok, so what how could I wire to be constantly feeding from the lift pump?

I think the comment from the_stoat is telling you that your plan to use the OEM pump as a lift pump is a bad idea because the pump itself is not suitable.

[Penelope Stopit]

David-1dyf3 said:

Wired up my 4 pin relay

30 to battery
87 to fuel pump
85 to ground to chassis.

86 to output from OEM fuel pump relay to OEM pump

When OEM fuel pump relay triggers whatever pump you use for a lifter, swirl pot pump is triggered a few milliseconds later

Should the OEM lift pump circuit fail, the swirl pot pump will stop running (nice)

Don't forget to fuse the supply to swirl pot pump relay terminal 30

[David-1dyf3]

Cool. So a low pressure, high volume pump rated below the walbro HP 255LPH, say 190LPH as a lift pump.
Would this still need restricting on the overflow back to the tank?

Also would I hardwire this lift pump then and not use the factory wiring?
Wire it to be a constantly on. (Or switching on via grounding switch if I wanted)

[Penelope Stopit]

Crossed posts

See above

[the_stoat]

GreenV8S said:

I think the comment from the_stoat is telling you that your plan to use the OEM pump as a lift pump is a bad idea because the pump itself is not suitable.

Exactly this. You may want to consider a Walbro GSL395 or equivalent. For piping up SBD motorsport have a very good diagram on their website.

As per the previous post using the OEM feed or relay so that if the in tank pump stops so does the post swirl pot pump. Do not wire it as an always on as that would not be too useful if you have a big off.

I do not know why you want a restictor in the return as all it is doing is going from the swirl pot to the main tank. As would happen on the injector return if your swirl pot was not there.

Also if it were me I would also have a fuse, as previously posted, on the swirl pot fuel tank pump and also use a ignition switched live as opposed to a direct battery feed.

Edited by the_stoat on Tuesday 14th July 13:31

[Penelope Stopit]

Penelope Stopit said:

David-1dyf3 said:

Wired up my 4 pin relay

30 to battery
87 to fuel pump
85 to ground to chassis.

86 to output from OEM fuel pump relay to OEM pump

When OEM fuel pump relay triggers whatever pump you use for a lifter, swirl pot pump is triggered a few milliseconds later

Should the OEM lift pump circuit fail, the swirl pot pump will stop running (nice)

Don't forget to fuse the supply to swirl pot pump relay terminal 30

Credit to the_stoat for above information, the_stoat did post the same earlier, just added a little to it

the_stoat...............Sorry, I should have quoted your earlier post and added a little

[the_stoat]

Penelope Stopit said:

the_stoat...............Sorry, I should have quoted your earlier post and added a little

Not a problem i could have been far more explicit

I may look like being pedantic, but the fuel system, and the control of it, is something to make sure you get right.

[David-1dyf3]

So things to do

1. Already fused #30 before the relay but have it on the battery but *will change this to an ignition 12v* 👍

2. *Get a low pressure lift pump, flow rated lower than 255LPH*

3. Keep the factory wiring for the lift pump? :-

• * I would keep the factory signal to trigger both lift pump and swirl pot pump? Just to be clear on that***

3.B would you then do new wiring for the low pressure fuel pump with heavier gauge wiring. (This I don't think will be required since it's low pressure and 12v factory wiring will be fine? )

4. Restrictor was just what information I was researching, this was apparently to put load on OEM fuel pump to replicate its operation when it was in factory setup. Instead of running flat out continuations.
But I'll drop that idea since I'll be going low pressure pump.

Thanks guys👍

[Penelope Stopit]

Is there something you don't understand about the following

Have tried to explain it as best as possible

Leaving the OEM fuel pump circuit as is

You have added a relay and should be wiring it as below (you have already posted three quarters of the job)

30 to battery
87 to fuel pump
85 to ground to chassis

And to finish the job

86 to output from OEM fuel pump relay to OEM pump

When OEM fuel pump relay triggers whatever pump you use for a lifter, swirl pot pump is triggered a few milliseconds later

Should the OEM lift pump circuit fail, the swirl pot pump will stop running (nice)

Don't forget to fuse the supply to swirl pot pump relay terminal 30

---

There is nothing to gain from wiring terminal 30 (relay supply) to the ignition, there is much to lose

Edited by Penelope Stopit on Tuesday 14th July 17:09

[David-1dyf3]

Right am with you, I got it. Thanks for being patient electrical is not my strong suit!👍

Effectively if the OEM pump is 12v switched I could tap at right at the pump plug before it goes into the tank.

Thanks for the diagram!

[tapkaJohnD]

David-1dyf3 said:

Right am with you, I got it. Thanks for being patient electrical is not my strong suit!??

Effectively if the OEM pump is 12v switched I could tap at right at the pump plug before it goes into the tank.

Thanks for the diagram!

What's this "&#128077"?
It appears when you type "??", and when copied as above reverts to that.

[Penelope Stopit]

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Edited by Penelope Stopit on Wednesday 15th July 10:56

[Penelope Stopit]

David-1dyf3 said:

Right am with you, I got it. Thanks for being patient electrical is not my strong suit!??

Effectively if the OEM pump is 12v switched I could tap at right at the pump plug before it goes into the tank.

Thanks for the diagram!

No problem, glad to be of some help

Yes you can connect into the OEM fuel pump circuit close to where you are fitting the added relay, it's always nice if the battery is in the back of the car or there is a heavy battery positive down the back, easy to supply the added relay that could go in the boot space