anti-surge mod

[Garrison]

I remember seeing something a long time ago (can't remember if it was here, or NASIOC) but there was something called an anti-surge mod that you could do to your fuel pump which would keep the car from lurching/stalling after taking a hard right-hand turn.

Can anyone give me a link to this? I've searched and come up empty-handed each time.

[Huffer]

It's the way the fuel sits in your tank and where the fuel pump pickup sits. You could add more baffles to the tank to prevent fuel from sloshing away from the pickup. It should only happen if you are running pretty low, like 1-2gallons in the tank.

[Garrison]

Well unfortunately it's happening fairly frequently. For instance there is a decreasing radius turn near my house and I take that at around 30-40mph, directly after the apex, it begins to ascend up hill and the car begins to bog very badly. Give it a second and it picks up the fuel again and la-dee-da it's fine, no problem. The same thing happened when I pulled into the Home Depot the other day (similar road situation).

So while it may only happen when the car is turned hard right, it just so happens that I live in western North Carolina, one of the most mountainous states in the country.

[Huffer]

Have you pulled the fuel pump out of the tank? It's possible your pickup tube fell off or even the filter bag is clogged.

[chuckthefuk]

"Zak" had the same problem.. his fuel pump eventually gave him issues so in went a Walbro 255 and no surging since..

-Chuck

[Garrison]

I did pull the fuel pump to install a walbro 255, it came with a brand new filter bag, so I can't imagine that's ruined yet; however I'll check the pickup tube. I have the Haynes manual, but the parts fiche for the fuel pump doesn't show the pickup tube. Can I get a picture for reference?

Thanks

[Reason]

Your fuel senders could be going.

[ouch1011]

Something is wrong with your car. My car will do this only at less than 1/4 tank and only on REALLY hard/fast corners. Easy fix there--fill the tank.

Remove the fuel pump, make sure the pickup screen didn't fall off, and the pump actually reaches the bottom of the tank. Also look for any loose baffles.

The owners manual for my 06 actually says not to take hard corners with the fuel level low. Kinda laughed when I read that.

[anothernord]

http://www.ludicrous-speed.com/wiki/ind ... _slosh_mod (http://www.ludicrous-speed.com/wiki/index.php?title=Shanes_impreza_fuel_slosh_mod)

[Garrison]

http://www.ludicrous-speed.com/wiki/index.php?title=Shanes_impreza_fuel_slosh_mod
That's the one. You're the man 'Nord :smt023

[Garrison]

Read thoroughly both Shane's page, and this thread: http://www.rs25.com/forums/f128/t49108- ... -help.html (http://www.rs25.com/forums/f128/t49108-fuel-cut-when-racing-help.html)

Made my own surge tank with a 32oz Dubro (for those with similar problems, allow me to recommend the 26oz, as it is smaller and easier to manage getting in and out of the tank, which I assure you was a numerous occasion kindof thing.
I test fit it at least 4 times with various cuts and bolt hole configurations (I think because I had bent the rail on the fuel-pump carriage it wasn't sitting quite right in the gasoline and the car wouldn't start. I.e. the fuel pump sock was elevated out of the fuel sitting in the surge box, starving the pump). Once I went through a few trial and errors, I figured it out, re-bent the rail, and ended up with a fairly short box (another reason to go with the 26oz in the first place); but I got it done.
Haven't had a chance to test it yet, but I intentionally kept only a 1/4 of fuel in the tank before doing this mod (both to keep my hands as gasoline-free as possible and to check to make sure the mod did the trick). Will report back with the conclusion once it has been tested.
By the way, for anyone following the thread, there isn't anything "wrong" with my car. A stiffer rear sway bar neutralizes the car's natural under-steer tendency by reducing grip in the rear, this along with reinforced end-links is enough of a suspension performance modification that in my general geographic area, this surge-tank is almost a requirement (due to various sharp corners and elevation changes).

[Garrison]

Well, it worked. I would rate the mod's effectiveness 8 out of 10, as I can take sharp right handed uphill corners on 1/8 tank with just the faintest bit of fuel cut, but the fueling on <1/8 tank is still somewhat spotty. For some reason it will act up like the TPS sensor was going bad, but that makes no sense, as I just replaced it and it works fine.
And allow me to retract my previous post's last statement; as minor as the problem may be, I certainly would not call it normal.

[Garrison]

TPS adjusted, car runs perfectly. Mod score changed to 10 out of 10. And, I retract my retraction... Oh snapple o.O

/Thread