Necessary to hardwire walbro 255lph fuel pump?

[brandnew161]

As the title states, is it necessary to hardwire the 255? My 2g has the wires all pre-run and ready for hook up to the pump. The previous owner had the stock pump hardwired. However when I installed the 255 i disconnected those wires. Is it really necessary? Would there really be a difference anyways? Thanks

 

[jdodds]

either way youre gonna mess up your fuel trims if you dont have an aftermarket fpr. Get one of those before you do tons of driving. rewiring it makes it pump a little more. I think it only gets like 10-11 volts on stock wiring. the rewire helps it run at around 14

 

[asrdave]

i was wondering the same, i have a fuel lab fpr, do i really need to rewire my pump?

 

[TuRBoTaLooN]

Yes you will need to re-wire. The stock wiring is too small to get enough current to the 255 to fully power it.

 

[DSM_PWR]

Technically... its not necessary to Re-Wire the fuel pump... plenty of people have made good power without it however...

it is recommended and you'll gain a huge advantage by doing so by increasing the voltage to the fuel pump.. makes a big difference when going for higher boost at higher RPMS

 

[14spectre88]

Definitely re-wire it. Fuel pumps were designed to operate at 14v (the voltage the car is supposed to supply assuming no voltage drop). Like stated previously, the stock wiring only allows 10-11v, which can limit the actual amount of fuel flow. You should read up on this article at RRE: Voltage vs Fuel Flow

 

[dave99gst]

If you already have a new FPR then you midas well re-wire it. If you are trying to get buy on the stock FPR then leave the stock wiring.

 

[brandnew161]

I have a aeromotive afpr, all that stuff is in my profile. Like i said all the wiring is there it just needs to be hooked back up. When I bought the car the Denso fuel pump had died and it was hardwired and I was iffy on hardwiring the walbro because I didnt want it to crap out. Maybe it was just old.

+1 on todays to do list

thanks for the replys

 

[-TunedDSM-]

Necessary? No.

Beneficial? Yes.

 

[Jets303]

When I tested my voltage on my stock wired 255 it was at a 9.2v! I rewired and retested with a voltmeter and found 13.7 all day. I would do it for the sake of your pump, plus its an easy fun and cheap little project.

 

[toofast82]

Here's the flow differences between rewired on non for most popular fuel pumps, its a good difference
RRE Instructions

Would you run a badass sound system on 18gauge wire? I don't think so.

Although the 255lph non-rewired may be able to supply plenty of fuel, rewiring it will provide much better voltage consistency all around especially when you turn on your turn signals, electric fan goes on,etc.

 

[brandnew161]

^^^funny you say that because when I have the stereo off and can actually hear the fuel pump, when I put on my turn signal the tone of the pump changes. Almost like its not getting enough power....well that is whats happening . I'm planning on doing this soon, been tied up helpin my sisters bf repaint his v6 galant

 

[LKWTSI]

Can't really argue against not doing it, but I had the rewire kit before I had my 255. I now have the 255 rewired and I don't think it'll be a bad thing. The good thing so far is that with the combo, I now have no knock

Call it lucky, but I'm happy to have the pump rewired.

 

[blackrosenova40]

I dont think anyone has ever said the correct answer. This question has been asked many times. The correct answer would be to voltage drop the power side and ground side of the pump. Put a multimeter lead on the positive side of the pump and the other lead on battery positive. Run and check, anything above .4 volts is too high and needs a larger wire, or you have a corroded/bad connection. Same test works on the ground side.