StalkerLS1

Chris99WS6PWTMET & I will be installing a Walbro 340 in my Car tomorrow morning. I already have an Inline pump back there and a really nice 12volt supply line feeding power directly to the inline. My question is, since were going to be getting rid of the inline.. Is there a way to wire up the Walbro to utilize that good supply of 12vots vs just splicing into the existing system?

As I understand it, if you can run a tap off the actual battery (Which I am)you can get 13-14 volts to the pump for optimum performance. The problem is Chris nor I know how to do that. Can anyone explain what's involved?

Most appreciated!

-

<small>[ April 18, 2003, 01:16 PM: Message edited by: StealthStalkerLS1 ]</small>

JNorris

iTrader: (4)

Get a Single Pole Double Throw relay (SPDT) rated at 30Amps.
Use the existing 12vdc wire coming from your battery to your existing inline FP and hook it to #30 on the relay. Hook #85 to a ground.
Cut the 12vdc wire (gray) that feeds the existing in tank FP. Hook the FP side to #87 on the relay. Hook the other half of the 12vdc wire (gray) to #86 on the relay.

Now when you start the car the and the PCM tells the FP to turn on there will be 12vdc applied to #86 causing the coil in the relay to energize and making the connection between #87 and #30. This will apply the battery voltage to the new in tank FP. When you turn off the car the 12vdc will be removed from #86 turning the in tank FP off.

Be sure to put a fuse (20amp) on the 12vdc lead coming from the battery.

See link below for a drawing.

FP Hookup

John

<small>[ April 19, 2003, 09:05 AM: Message edited by: JNorris ]</small>

Chris99WS6PWTMET

Shouldnt the wiring from the new relay to the in-tank also be changed to a larger size?

Seems like it would defeat the purpose since it is funneling back down to stock wire size from the new relay. Did you notice any difference in your FP with this set up?

Any particular reason you went hot to 87 vice 30? As 30 is usually used as the 'common' input. It can go either way I presume.

Thanks for the schematic and the info.

StalkerLS1

Ahh.. I see.. This makes sense to me because My vortech Inline is currently setup almost this exact way. I just spliced onto that existing gray wire as a trigger to fire up my Inline. Okay so that's the actual wire that powers the intank pump and what your saying is cut one side of it (From Fuel Relay) and use it as the Relay Trigger and the other side of it (To Intank Pump) put on the relay (30) so that when the Relay is Energized it connects the dedicated 12volt line to the the Gray Intank Pump Line. Essentially 87 to 30.

I also understand Chris's concern too. My theroy is that maybe the stock Gray Wire is running thru a few different circuits in the vehicle before it actually reaches the tank where as the dedicated 12volt supply is tapped right off the battery. Maybe we can have a look at that gray wire that feeds to the tank and see if it would be too much trouble to replace it with a heavier gauge wire. If it's too much then we'll just go with the above for now.

Thanks guys!

See ya bright and early there Chris!

Brian.

JNorris

iTrader: (4)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Chris99WS6PWTMET:
<strong> Shouldnt the wiring from the new relay to the in-tank also be changed to a larger size?

Seems like it would defeat the purpose since it is funneling back down to stock wire size from the new relay. Did you notice any difference in your FP with this set up?

Any particular reason you went hot to 87 vice 30? As 30 is usually used as the 'common' input. It can go either way I presume.

Thanks for the schematic and the info. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Chris,

Yes you would really want to change out all the wire to the FP but I do not think you can get the larger wire through the grommet on the top of the tank.

The voltage drop across the stock wire (16AWG? At 12ft) would be .49v assuming 10amps of current draw. 10AWG would be .12v and 12AWG would be .19v.

You are correct about using 30 verses 87. I will change the drawing.

Chris99WS6PWTMET

We got it in and wired today. See what you mean about the wire to the pump, we left it stock. Thanks for the info JNorris.

MikeB

Did you stick with the stock relay and wiring or use any of the inline setup. I'm doing the same thing, getting rid of the inline pump.

StalkerLS1

Mike,

since you already have a relay back there with your inline.. part of the work is already done for you. Same story with my setup. so it was pretty easy.. Just follow JNorris's instructions and you should have no problem.

MikeB

What I have is a Aeromotive inline pump and a Aeromotive Fuel Pump controller. The controller is spliced into the stock relay gray wire and also into the PCM (for tach signal) to switch from low speed to high speed. The aeromotive runs at low speed until you hit the RPM it is adjusted to. At low speed it is loud not to mention at high speed. I was wanting to get rid of it and judt upgrade the intank pump. Am I doing the right thing and can I use the stock relay/wiring setup?