Fuel cut after cornering

BSOD2600 · Post by **BSOD2600** » Wed Jul 09, 2008 6:23 am

Basically ever since I've had my TW (well after the dead engine and 4EAT was replaced with a 5MT), I've had some sort of power problem after coming out of large corners. I've noticed this happens when I'm below 1/2" tank of gas. The corners I'm talking about are typically the big cloverleaf on-ramps to the highway.

I'll be at half throttle throughout the turning, then once the road straightenes out, I'll go WOT. Some times, I get a jerking or power loss, where I'll then take my foot off the accelerator. Car comes back to life, and then I go WOT again. Some times it goes fine and other times it'll loose power again. I'm assuming the power loss is due to fuel cut? During the loss, I don't ever recall the rpms/boost drastically dropping off.

Since I've had the car, I've already replaced the plugs, wires and fuel filter. My gas guage is pretty accurate still. Do you think my problem is a sign that the fuel pump is going bad, something more drastic, or a problem all these cars have?

bmxkelowna · Post by **bmxkelowna** » Wed Jul 09, 2008 7:51 am

right hand turns right?
both tlegs ive owned have done it (which sucks balls for autox!!!)

the baffling in the gas tanks are really bad and basically on right hand turns all the fuel sloshes away from the fuel pump

douglas vincent · Post by **douglas vincent** » Wed Jul 09, 2008 8:22 am

I simply replaced the fuel pump with a walbro. Presto! Zero cornering problems!

ciper · Post by **ciper** » Wed Jul 09, 2008 8:59 am

Surge tank with second fuel pump?

BSOD2600 · Post by **BSOD2600** » Wed Jul 09, 2008 10:30 am

bmxkelowna wrote:right hand turns right?
both tlegs ive owned have done it (which sucks balls for autox!!!)

Yup, far as I can recall. Seems to be the norm for how the DOT makes them in WA

.

douglas vincent wrote:I simply replaced the fuel pump with a walbro. Presto! Zero cornering problems!

That is on my to-be-replaced-list for this summer. Guess I'll be bumping that up sooner.

It's a "Walbro 255lph" right? or should I go for the Walbro 255lph-hp

With a VF39, tmic, etc would I even be close to needing the extra PSI the -HP pump can put out?

BXSS · Post by **BXSS** » Wed Jul 09, 2008 1:02 pm

The HP does not give you more PSI, it gives you more GPH/LPH @ the higher pressure levels.

Get the HP, it is meant for force-inducted applications (turbo / supercharged) - thats what I have on my cars.

I have not really tried hard corners with the SS, but even with a Walbro there is fuel starvation on HARD corners when the tank is low (Less than 1/4 tank) on my Impreza.

dscoobydoo · Post by **dscoobydoo** » Wed Jul 09, 2008 2:33 pm

BXSS wrote:
I have not really tried hard corners with the SS, but even with a Walbro there is fuel starvation on HARD corners when the tank is low (Less than 1/4 tank) on my Impreza.

I ALWAYS get fuel cut on less than half a tank on hard corners.

BSOD2600 · Post by **BSOD2600** » Sat Jul 12, 2008 3:00 am

Alright so I'm set on getting the Walbro 255LPH-HP. I've noticed some sites have options to add on the WRX kit (strainer, clamps, fuel hose, rubber mount and connector, etc), while others is just the pump.

Do I need any of those extra add-on parts or is the 255LPH-HP really a direct swap from the OEM?

Any recommendation on a quality site to buy it? Sure I can search google for 255LPH-HP and find a ton of sites, but I want something which ya'll have had positive experiences with. So far either Innovativetuning.com or subaruparts.com seem to be decent finds.

bmxkelowna · Post by **bmxkelowna** » Sat Jul 12, 2008 3:23 am

i put a 255lph in my last legacy and it didn't help the low fuel cornering issues

BAC5.2 · Post by **BAC5.2** » Sun Jul 13, 2008 1:29 pm

Mine only did that on ONE corner. It was a bummer too, because it's the PERFECT corner to slide through.

RJ93SS · Post by **RJ93SS** » Sun Aug 17, 2008 5:25 am

mine has never even done that on fumes... isn't there a jet pump in the tank as well that sends the fuel from the drivers side to the pass. side??? maybe all you guys are having problems with your "jet pumps" check yours haynes or whatever and i think you can diagnose it through the trunk.

Post by **Legacy777** » Sun Aug 17, 2008 4:53 pm

All the "jet pump" is, is a syphon created by the return fuel coming from the engine. There's not really much that can go wrong with it as long as something's not clogged.

ultrasonic · Post by **ultrasonic** » Sun Aug 17, 2008 7:05 pm

Fuel starvation.

I had this happen on agressive street driving and the autocross course in my 91. Have not pushed the 94 hard enough to find out yet.

If I keep more than 1/3 of a tank during autox, it no longer happens.

BSOD2600 · Post by **BSOD2600** » Mon Aug 18, 2008 5:40 am

Legacy777 wrote:All the "jet pump" is, is a syphon created by the return fuel coming from the engine. There's not really much that can go wrong with it as long as something's not clogged.

Is the "jet pump" the set of tubes with the orange end in this pic?

I still have yet to really corner hard since the Walbro install to see if my fuel starvation problem still exists...

Post by **Legacy777** » Mon Aug 18, 2008 2:37 pm

More or less.....yes that's the device that creates the suction for the "jet pump" on the other side of the tank.

NICO · Post by **NICO** » Tue Aug 19, 2008 1:23 am

i get this when my fuel is low around corners very hard, to fix make sure your full on gas and your good.

impreza_GC8 · Post by **impreza_GC8** » Thu Aug 21, 2008 7:38 am

This happens with my Impreza. Happened to me at the last autoX. It hasn't happened with my Outback because I'm afraid to take corners too quickly with it, lol.

BXSS · Post by **BXSS** » Thu Aug 21, 2008 8:48 pm

A real fix would be to fab a surge tank.

Fuel will go from the gas tank to the surge tank via whatever fuel pump is in the tank, then from the surge tank it will get pushed to the fuel rail via a inline Walbro 255HPHV, or if you have a aftermarket fuel pressure regulator with multiple inputs you can use 1 walbro 255 per fuel rail, the return line will go back to the top of the surge-tank which will connect the the gas-tank's return line via another fitting @ the top of the s-tank & hose - once the surge tank is 100% full fuel will begin the go back to the gas tank.

Simple!

Then you will not cut fuel on hard corners, you'll just spin bearings until you dry-sump the car....

NICO · Post by **NICO** » Fri Aug 22, 2008 12:42 am

BXSS wrote:A real fix would be to fab a surge tank.

Fuel will go from the gas tank to the surge tank via whatever fuel pump is in the tank, then from the surge tank it will get pushed to the fuel rail via a inline Walbro 255HPHV, or if you have a aftermarket fuel pressure regulator with multiple inputs you can use 1 walbro 255 per fuel rail, the return line will go back to the top of the surge-tank which will connect the the gas-tank's return line via another fitting @ the top of the s-tank & hose - once the surge tank is 100% full fuel will begin the go back to the gas tank.

Simple!

Then you will not cut fuel on hard corners, you'll just spin bearings until you dry-sump the car....

LOL i rather let it do its thing with the no gas! so i will back off, then have it do the last part you siad LOL!!!

BXSS · Post by **BXSS** » Fri Aug 22, 2008 1:48 am

Pros & Cons with everything right....

NICO · Post by **NICO** » Fri Aug 22, 2008 8:24 am

o ya for sure!!!

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Fuel cut after cornering

Fuel cut after cornering