Fuel Pump Relay - how and what?

[hegg]

I've read several threads about "hot wiring" the fuel pump with battery voltage to help with fuel PSI. Additionally (and this is my situation) others have mentioned that this is nearly a necessity if you are upgrading your fuel pump to a higher capacity.

Unfortunately, I'm an electrical bonehead and am incapable of interpolating what needs to be done, despite some great information from web sites like: BOEFabrication.com | Beyond Original Equipment

I've run wiring and put connectors on and all that - I'm not worried about that so much. I just don't have a clue what relay to buy, what numbers need to be on it, which wires to splice and attach to what and where.

Searching through the forums didn't yield any results for me, but I could have easily missed a good write up.

Anyone have the expertise in this area?

Thanks!

[turbophil]

The fuel pump relay did help a little, as I mentioned in that write up. However, it's probably not worth the hassell unless you're upgrading the fuel system all together. The stock pump will get the job done for all the baby FI kits out today. Is it undersized for FI, yes. Will hot wiring help for FI applications? A little-- but not enough to bother with it... If you want to upgrade your fuel system, a different pump is really in order. That said, be careful about blindly upgrading your fuel pump, as your tune may not like the FP change that results from a bigger pump. An adjustable fuel pressure regulator will be your friend if you're upgrading pumps for a tune that was otherwise designed for the stock pump...

Regards,

TP

[hegg]

Thanks for the reply! I have a VF Stage II kit on its way with the upgraded fuel pump. I read in a few threads that the new one is much louder and some say it's due to the pump not getting adequate voltage (although I would expect a higher volume pump to create more noise regardless) and that a proper fix would be to power it through a relay.

So am I barking up the wrong tree? I just figured while I have the whole car in pieces, I might as well do a few minor things like that to ensure longevity.

Hegg

[turbophil]

Wrong tree if you're worried about noise. The walbro pumps are cheap, reliable, and robust... Cheap can mean noisy... in this case, it does. I recommend to use a stock pump as lift pump for the surge tank solution we use and then a Walbro in the surge tank. That keeps the noise out of the cabin. To be fair, once you start the car, the racket of the blower and the engine completely overwhelms the walbro even when installed in the fuel tank...

The relay is fine idea to ensure adequate voltage to the pump, but it's not mandatory by any means...

TP