Walbro fuel pump upgrade - is 12V mod required?

[scotty]

Hey,

I'm about to install the walbro fuel pump.. and wondering if I really need to do a 12V mod? What will happen if I use the stock wiring?

I've got no plans of tuning or such, only running Lexus AFM, 550s, AFPR. Just installing the walbro before selling the car.

Scott

 

[toyotanos]

Its not a bad idea to run the pump at 12v at all times, most AFPR's should be able to handle the extra flow (unless its a really small, cheap one) might as well be a little safer and make sure you don't run out of fuel in the mid-range!

 

[digihonk82]

I took my resistor out b/c at idle I could hear the Walbro in my tank struggling with the 9volts. Works great. Gas mileage suffers in the city.

 

[OfnaRcR4]

It is not required. It's noisy at 12 volts too.

 

[shaeff]

The only real reason to do this is when tuning the car, it takes out the "unknown" of the voltage switch from 9 to 12v. That switch is a pain to try to tune the car around.

If you don't tune the car, I'd leave it as-is, personally.

 

[CyFi6]

I looked up the Walbro specs and at 50 PSI it can pull around 10 amps. I would be a little wary running that on all the stock wiring. I don't know what gauge the wiring is but I don't remember it being very big.

 

[shaeff]

Anyone doing the 12v mod should be running something along the lines of 10 gauge wire along with a new relay. I just don't trust the old wiring anymore.

 

[mecevans]

Im installing my wabro tomorrow. I have my j-tube drilled out and i dont plan on doing the 12v mod

 

[CyFi6]

The pump still runs at 12v under certain conditions, potentially overloading the circuit, I wouldn't do the Walbro pump without the 12v mod with larger gauge wiring that shaeff mentioned, then again I haven't crunched any numbers for what the stock wiring can handle.

 

[scotty]

Thanks for the replies!

What about a constant 12V mod? Or do you have to use a relay?

 

[Devin LeBlanc]

I burned up two FP resistors with the walbro at 55 PSI base pressure. I would recommend doing new wiring with a new relay

 

[scotty]

Thanks for replies so far.

So it's OK to just swap fuel pumps, and use stock wiring / not doing any changes what so ever? Not doing any tuning, just want the car to run smoothly without fuel cut.. main goal.

Basic mods worth mentioning:
Lexus AFM, 550cc's, AFPR, 2.5" IC pipes, Apex-i filter, 3" radiator, 3" exhaust.

What base pressure should I set it too?

 

[metaphysico]

run smoothly without fuel cut.. main goal.

Um barking up the wrong tree. Fuel cut is done by the computer, has nothing to do with the fuel pump.

 

[mecevans]

At stock fuel pressure i think you would be fine. Mine has not given me trouble.

 

[scotty]

I know lol.. just meaning as long as the pump works fine and fuel flow is good.

What's stock fuel pressure? Should I run stock FP with 550s?

 

[supraguy@aol]

I've run my Walbro without the 12v mod for 5yrs now, but I only boost to about 12psi max, and it's tuned rich.
When i go to a T-4 after the summer, I'll be doing the rewire. And as Shaeff pointed out, the 9-12volt switchover does play havoc
with AFR adjustment when you're going for max power.

 

[gte-power]

hey guys i'm not really familia doing electric stuff on my car...but i think i really need to do this mode to my car to
since i'm runing 15-psi my car on top end start to run lean..and i do have a walbro in my car!!!!!!!!!!
i have 1jz in my 89 supra...can some post here the instruction how to do it plz
thank you so much

 

[IwantMKIII]

^I know there are instructions on the site, search for them. I can't find them right now. I just want to make clear, the only reason to do the 12V mod is for tuning purposes, though at 15psi, you SHOULD be tuning if you aren't already. Running lean at 15 psi on a stock turbo is dangerous.

 

[GrimJack]

^I know there are instructions on the site, search for them. I can't find them right now. I just want to make clear, the only reason to do the 12V mod is for tuning purposes, though at 15psi, you SHOULD be tuning if you aren't already. Running lean at 15 psi on a stock turbo is dangerous.

He's not running a 7M. 15psi on the 1J isn't all that much.

 

[IBoughtASupra]

hey guys i'm not really familia doing electric stuff on my car...but i think i really need to do this mode to my car to
since i'm runing 15-psi my car on top end start to run lean..and i do have a walbro in my car!!!!!!!!!!
i have 1jz in my 89 supra...can some post here the instruction how to do it plz
thank you so much

Are you on stock 370CC 1JZ injectors? If so, 15 PSI is not really safe. If you are in a single, it's even worse.

Get a bigger set of injectors and something to tune with.