Fuel Pumps

bluesubaru · Post by **bluesubaru** » Wed Jan 19, 2005 4:23 am

Hi all,
I have a 95 Legacy 2.2 Turbo @ 5psi with a wrx turbo and IC and using the emanage. I am maxing out my injectors at about 5500rpms and was curious if a fuel pump would help any?

Also what fits/works better, the walbro or the wrx fuel pump?
I have seen subaru owners use both, any opinions?

Thanks
David

J-MoNeY · Post by **J-MoNeY** » Wed Jan 19, 2005 4:47 am

It couldn't hurt to do it.

My stock Legacy one, was well as other people's turbos, flows a little more then the WRX one, so that idea's out. I'd get a Walbro 225. I *think* the part number is GSS341.
Don't quote me on that. I'd do a search on here and online and see what you can do.

http://bbs.legacycentral.org/viewtopic. ... ght=walbro

THAWA · Post by **THAWA** » Wed Jan 19, 2005 6:06 am

A new fuel pump shouldn't change anything theoretically. What injectors are you using?

J-MoNeY · Post by **J-MoNeY** » Wed Jan 19, 2005 6:12 am

THAWA wrote:A new fuel pump shouldn't change anything theoretically. What injectors are you using?

How could it not? Big injectors capable of flowing more fuel then the pump can dish out. Makes sense..

THAWA · Post by **THAWA** » Wed Jan 19, 2005 6:27 am

How would the injectors be maxed out then? And I said theoretically. Of course it's going to make some difference. Even going from one pump to another pump of the same type would make a difference.

dzx · Post by **dzx** » Wed Jan 19, 2005 7:29 pm

Is your e-manage correctly tuned and why are you only running 5psi?

THAWA · Post by **THAWA** » Wed Jan 19, 2005 9:42 pm

I believe it's an EJ22E with a turbo kit. Right David?

tris91ricer · Post by **tris91ricer** » Wed Jan 19, 2005 9:50 pm

Yes, GS341 is the correct one for our cars. Ask Douglas or Phil, they'd know more firsthand, and they've used the only two that fit.
Also, to keep in mind that your MAF could be throwing your injectors to 100% duty cycle after a certain point. vrg3 has some more info on that, as well. Apparently after something like 200cfm, it throws the injectors to the max. what about your FPR? got anything in that dept?
although, for only 5psi, you shouldn't be running out of fuel...

bluesubaru · Post by **bluesubaru** » Wed Jan 19, 2005 9:59 pm

yeah I suprised to about running 100% at only 5psi, I would do more boost, but I wanna get all the kinks out first, then I will do about 7-8psi. Its a NA EJ22 motor, turboed.
I have stock Legacy injectors right now.
But back to the main ?

THAWA · Post by **THAWA** » Thu Jan 20, 2005 3:00 am

The ones that came with the car? Aren't those only 270cc's or soemthing? You need injectors that flow more.

bluesubaru · Post by **bluesubaru** » Thu Jan 20, 2005 5:22 am

I thought they were only 240cc's and the RS were 270 or 280cc.
But back to the main topic? Which fuel pump?

THAWA · Post by **THAWA** » Thu Jan 20, 2005 5:32 am

Yikes, you really need better injectors then. Especially if you're trying to go with 7-8 psi. The way our fuel system is setup the pump doesn't make the injectors flow more. If you have 240cc injectors, they're only going to flow 240cc. You can get a walbro but it's not going to make your injectors flow more. That said, when you do get higher flowing injectors, you will need a higher flowing pump such as a walbro. As J-Money and Tristan said the GS341 is the right one (or so I've read).

douglas vincent · Post by **douglas vincent** » Thu Jan 20, 2005 5:52 am

Bluesubaru,

if you have the 270 cc or smaller injectors, there is about no way in heck you will be able to go over 5 psi, and that in itself is stressing the system.

I got around this for a short time by installing the walbro 255lph fuel pump, which required some fitment issues to be resolved ( new clip ends and a zip tie) and a rrfpr of 1-1 ratio. Dont know if the rrfpr really helped but the fuel pump did.

As soon as I was 5 psi and above, the car kept bogging out horribly because of lack of fuel. I was able to cure this by installing new 370 cc nismo injectors. Then I was running incredibly rich and getting bad milage. I cured this somewhat by intercepting MAF signal and using a 50k poteniometer to trim the air/fuel ratio.

Now I get 15-17 miles to the gallon, no detonation and can run 7-9 psi (intercooled.)

bluesubaru · Post by **bluesubaru** » Thu Jan 20, 2005 5:03 pm

50k poteniometer?
Yeah I know WRX injectors are too big, I would have to use the emanage to back the fuel off at low rpms, but I know RS injectors should be good. I can also use the emanage to make the injectors flow more at certain RPMS, but not more than 240cc or whatever they are. I am only wanting to push 5-6psi, and my fuel pump now is starting to go and cause problems, so when I go to replace it I would like to know what would fit the best. My car does not bog at all at high rpms, like I am hitting just the right amount of fuel.

douglas vincent · Post by **douglas vincent** » Thu Jan 20, 2005 5:16 pm

the 50 k pot is my ghetto AFC. since you have emanage you can of course skip this.

BAC5.2 · Post by **BAC5.2** » Thu Jan 20, 2005 9:36 pm

If you are running at 100% IDC, then your first order of business should be to upgrade to larger injectors.

See, with a fuel pump that is more capable, you still hit the limit of the fuel pressure regulator. So you can modify the FPR, and squeeze a few more CC's out of the stock injectors (which will require a bigger fuel pump to keep up with). Then, it's time for bigger injectors.

I don't remember which fuel pump I used, I think it was the 341. I know the Boostjunkie Legacy and now Matt used a 541 pump, but that was a little bit different in terms of connectors, and orientation of the pump.

bluesubaru · Post by **bluesubaru** » Thu Jan 20, 2005 10:24 pm

All I am trying to figure out is what pump will work for my car the easiest and still be considered a slight upgrade. I am fully aware of what bigger injectors do and why/when I need them. I just want to know what I can drop in and use.

BAC5.2 · Post by **BAC5.2** » Thu Jan 20, 2005 10:31 pm

Walbro 255lph. The 341 or 342 will work with some modding, I'm sure.

You can also use a MKIV Supra TT OEM pump, which is 255lph, and supposedly more reliable than a Walbro pump.

I was answering your question of whether or not it would help any. The answer is no, not without other mods as well. You will still be maxing out your injectors, reguardless of pump.

IronMonkeyL255 · Post by **IronMonkeyL255** » Thu Jan 20, 2005 11:28 pm

The GSS341 drops right in place of the stocker.

If you do get it, spend the extra $15 and get the installation kit, as that comes with a new pick-up filter, isolator, in-tank fuel line and everything else you need to install it.

I just recieved mine and installed it today.

MY CAR RUNS!!!!!!!!
After about 2 months of down time, it runs again.

BAC5.2 · Post by **BAC5.2** » Thu Jan 20, 2005 11:49 pm

Ironmonkey - Most people suggest using the stock bag, as it is larger than the Walbro bag. And with that, you can use the stock isolator.

The intank fuel line consists of a 2" peice of fuel injection hose.

What else does the installation kit include?

I bought mine from a friend of mine, out of his totaled WRX (he used it for 100 miles), so I dropped mine in the tank with what he used.

bluesubaru · Post by **bluesubaru** » Fri Jan 21, 2005 1:50 am

Nice, where did you get yours from?
And that fits all yr legacys?

BAC5.2 · Post by **BAC5.2** » Fri Jan 21, 2005 2:32 am

BAC5.2 wrote:I bought mine from a friend of mine, out of his totaled WRX (he used it for 100 miles), so I dropped mine in the tank with what he used.

The walbro pumps are all very similar, so you can make work whichever model you happen to have.

I know for a fact, that the 341, the 342, and the 541 all will able to be adapted to work. Mine bolted in, but Douglas Vincent got the same pump as me, and it didn't bolt up for him, so I think the whole carrier is different from the turbo and N/A Legacy. He got his to work, and mine works too.

The one for the WRX should work also (I think that's the 342?)

IronMonkeyL255 · Post by **IronMonkeyL255** » Fri Jan 21, 2005 2:36 am

I figured I might as well use the Walbro bag, as it fit correctly, and the stocker was pretty darn old.

Lemme see.....

It had the fuel line, 2 hose clamps, the bag, the wiring harness thingy (plugs the fuel pump directly into the stock location), the isolator, and install instructions.

I'm not sure if any of that comes with the basic pump, but all that was in a separate bag from the pump.

I'm sure all this could be had for cheaper if I looked, but this way I didn't have to look and I knew it all would work together.

I got mine from Dale Teague at Boxer4Racing.com. The pump was $89 and the install kit was $15.

The pump you see on his website is the GSS342. I'm not sure what the difference is, but I had heard that the 341 was a direct replacement for ours, so I got that.

The pump should fit all recent Subarus (all Legacies, Imprezas and Foresters). It may fit more, but I am willing to bet that it will fit those.

It was pretty easy to install. Just take up the mat in the trunk and remove the passenger-side plate there. You will be confronted with three fuel lines and an electrical connector.

The forward-most line I believe is the fuel return line from the engine. The middle line is the main fuel line. The back-most line is the line from the other side of the tank (I think..... correct me if I'm wrong).

I suggest undoing a few of the nuts (Some penetrating lubricant helps here, as these bolts may be rusted down) holding the in-tank assembly down to relieve the pressure in the tank before removing the lines (I used some more lubricant to make removal of the lines easier). I tried the other way, but that didn't completely do it.

Once everything is removed, maneuver the assembly out of the tank. Now just remove the electrical connector and fuel line on the pump itself and remove the L-shaped bracket holding the pump in.

Now just swap the new one in and reverse the removal.

IronMonkeyL255 · Post by **IronMonkeyL255** » Fri Jan 21, 2005 2:38 am

BAC5.2 wrote:The one for the WRX should work also (I think that's the 342?)

I do believe so.

I think the 341 was an earlier model for the WRX, but the 342 is slightly reworked to fit better.

BAC5.2 · Post by **BAC5.2** » Fri Jan 21, 2005 3:19 am

The 342 has the pickup on the opposite side, so you would need a zip tie to hold it in place. I think that's the difference.

You need to unplug a connector then start the car to depressurize the lines going to the engine. I did, and didn't spill a drop of fuel.

When I pulled the Boostjunkie fuelpump, we couldn't turn the car over (no engine), and I gas everywhere.

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Fuel Pumps

Fuel Pumps