How To Wire Up An Additional Fuel Pump?

[Garry 1]

On my last few outings on track I have been suffering fuel surge on right hand bends. To cure this I have purchased a Forge swirl pot and a Walbro external fuel pump. My plan is to mount the swirl pot and pump on a plate that I will put over the battery tray (the battery is being moved into the cabin).

 

I have got the fuel lines sussed, but I am after some guidance of how to wire the system up. I see that Spiky seems to have powered the external pump from the in tank pump, is there any way of tapping into the loom within the engine bay? What do I need relay wise?

 

Thanks

 

Garry

[swordfish210 20]

I wired my Facet pump to a switch in the cabin. I hard wired the switch to the battery, earthed the pump at the mounting point, and ran a live line from the pump (with a fuse in the middle) to the switch.

[Garry 1]

OK, I still haven't sorted this yet, and it must be completed by the end of next weekend!

I want to order the required bits and pieces this week so i have them for the weekend.

 

So to recap, I have a Walbro 255 L/PH external fuel pump sat in the engine bay just behind where the battery used to go:

 

 

 

I am putting the battery in the boot so I will have a live junction box mounted next to the swirl pot for my power source.

 

As I see it I have three options, wire it like Swordfish has kindly suggested with a manual switch, use a relay to turn the pump on with the ignition or just run a live wire from the pump in the tank with some sort of fuse back up to the engine bay.

 

I assume, as part of my bodged '6' conversion, I have a bypassed fuel pump relay located under the dash to the right of the steering wheel. I say bypassed as there is a small length of cable bridging two connections. Could I use this in some way?

 

Can somebody please help with suggestions on the safest/ best way to do this and give me any tips on what I need to make this work.

 

Thanks

 

Garry

[Mikey G 3]

Is the Walbro the main engine pump or the pump supplying the swirl pot? I would assume the former with the standard pump supplying the swirl pot from the tank.

 

Are you using the dual relay from the GTi6 loom?

 

I would wire the old tank pump to a fuse and relay thats either switched by an external dash mounted switch or triggered straight from the igntion.

 

The engine pump from the swirl pot should be wired in the same way your intank pump is currently wired from the dual relay (if fitted).

[Garry 1]

Is the Walbro the main engine pump or the pump supplying the swirl pot? I would assume the former with the standard pump supplying the swirl pot from the tank.

 

Are you using the dual relay from the GTi6 loom?

 

I would wire the old tank pump to a fuse and relay thats either switched by an external dash mounted switch or triggered straight from the igntion.

 

The engine pump from the swirl pot should be wired in the same way your intank pump is currently wired from the dual relay (if fitted).

 

Yes, the Walbro is the new pump that will be fed by the swirl pot. Tank pump supplies the swirl pot.

 

I don't know which relay I am running , although I am pretty sure the old 205 pump relay has been bypassed, as Miles commented on it when he worked on the car. So I may be using the 306 one, there is a something that looks like a relay about 15cm down from the actual ECU attached to the loom.

 

Edit:

 

The 'relay' I mean is just below and to the left of the big ECU plug:

 

 

So are you saying I could just splice into the feed going to the tank pump? Will that cause problems with over loading?

Edited April 28, 2008 by Garry

[Mikey G 3]

You could splice into the original fuel pump supply circuit and use that to trigger a relay that then supplies the external pump. The relay would need a permanent fused supply from the battery (or other supply point).

 

This would get you working and the trigger wire will not overload the original pump circuit, especially as the original pump will not be working under pressure anymore.

 

Yes that is the dual relay.

Edited April 28, 2008 by Mikey G

[smighall 1]

Gary,

 

I expect you will be using the standard 306 fuel/ignition relay. The bit where you can see the 2 wires connected is where the fuel cut off normally is, and often gets removed when doing conversions. You should in theory be able to tap into that without any problem.

 

Just find a switched 12v and put an inline fuse in for it.

[Spiky 37]

not sure i the pm, was before or after this post

 

with my setup, the old feed is used to trigger the two new relays, which then run 2 news feeds via fuses to each pump

 

so the ecu still controls the pumps

 

easy, job done