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Power loss around sharp corners -Solved-
Posted: Wed Nov 03, 2010 5:20 pm
by SiCkSTi04
This has been on my "To do" list since I got the car but have not had time until now. When ever making sharp turns or even U-turns while acceleration the car will lose power as if its not getting fuel. The car's rpm will jerk from 0 to 3k back and fourth until I let off the gas pedal then re-apply.
I have noticed when the fuel tank is low on gas it does it a lot more.
spec's: stock 92 SS manual with over 200k miles
Re: Power loss around sharp corners
Posted: Wed Nov 03, 2010 6:01 pm
by Florin1
My forester does the same thing. Its because its low on fuel, or getting low. I think the fuel pump is getting too weak @ 235K
Re: Power loss around sharp corners
Posted: Wed Nov 03, 2010 6:08 pm
by SiCkSTi04
yea could be the pump. this also happening on a full fuel tank or even half but like I said it happens a lot more when its low. Could a bad boost solenoid do this?
Re: Power loss around sharp corners
Posted: Wed Nov 03, 2010 8:35 pm
by sqc151
my 01 obs did this to. changed the fuel pump, fuel filter, plugs... nothing changed.
Re: Power loss around sharp corners
Posted: Wed Nov 03, 2010 10:24 pm
by BSOD2600
My 94 TW did this only when low on fuel (e.g. powering around highway on-ramps) Replaced the stock fuel pump with the walbro 255 and problem has never returned. Ditto for my 94 SS.
Re: Power loss around sharp corners
Posted: Thu Nov 04, 2010 9:39 pm
by SiCkSTi04
I'll start with check the fuel system first.
Re: Power loss around sharp corners
Posted: Thu Nov 04, 2010 10:26 pm
by 93Leg-c
I recently developed almost the same symptoms. From just above 1/3 full tank of gas when I make vigorous right-hand turns, I get what seems to be fuel starvation. Once I straighten out and feather the throttle for about 10 seconds, I can drive normally again. I believe it's because of the replacement fuel pump that I just put in. Let me explain:
My fuel pump was going out (after 220K miles) so I ordered one from ebay, making sure that all the electrical terminals, pump size, flow, etc was all the same. After installing it, that's when the fuel starvation began (I know it began then because I always make this particular 90* turn onto a certain highway). There was one notable difference in the replacement fuel pump: the sack filter stuck out at a 90* angle from the pump. The sack filter on the original pump extended downward at a slight angle.
Inside the sack filter is tubing that serves as an extended fuel pickup tube. What this means to me is that the original pump reached down deeper into the fuel tank which means the replacement pump cannot reach fuel that sits lower in the fuel tank. Since the pump is located on the right (passenger) side of the car, when I make my vigorous right hand turn, the fuel sloshes to the left side of the tank and leaves my replacement pump without any fuel to pick up and deliver to the engine. So, if I'm correct, I now have an "effective" 11 to 12 gallon fuel tank capacity since the bottom 3 to 4 inches of gas in the tank cannot be accessed.
In your case, SiCkSTi04, since the condition existed when you got the car, it might be possible that the previous owner had the fuel pump replaced with one that doesn't reach deep enough into the gas tank.
If you look at pics of the walbro pumps, the sack filter extends downwards and not at a 90* angle outward. Ebay sells replacement pumps that have the sack filters that extend downward, but the walbro is much cheaper than those so the walbro 255 pumps would be the obviously better choice.
This may not be the answer to your situation but it could well be. The only symptom that doesn't "fit" this potential solution is that your symptoms appear when you have a full tank of gas so yours could be the pump and/or fuel filter.
For others that have fuel starvation upon hard acceleration, the fuel could be sloshing over to the back of the fuel tank. Since the fuel pump is in the front of the tank, you could also be experiencing fuel starvation.
Re: Power loss around sharp corners
Posted: Fri Nov 05, 2010 6:14 pm
by SiCkSTi04
thanks for the feedback 93Leg-c, I need to visual see these. Does anyone have pictures of both pumps? Maybe have one or two from my wagon fuel pump upgrade some time ago.
Re: Power loss around sharp corners
Posted: Sat Nov 06, 2010 12:51 am
by BSOD2600
SiCkSTi04 wrote: Does anyone have pictures of both pumps? Maybe have one or two from my wagon fuel pump upgrade some time ago.
This thread has lots:
http://bbs.legacycentral.org/viewtopic.php?f=16&t=39500
Re: Power loss around sharp corners
Posted: Sat Nov 06, 2010 6:50 am
by 93Leg-c
Here's an example of a fuel pump with the strainer sitting at a 90* angle. (I'm not sure if it's connected but most fuel pumps sold on ebay will end up with the strainer at a 90* angle)
http://cgi.ebay.com/ebaymotors/91-94-96 ... 3f04105d7e
Here's an example of the strainer sitting at just a slight angle from the pump, although it's upside-down in the pic. But you can see how much deeper this pump reaches down into the gas tank (assuming the pump is the same height as the other pump).
http://cgi.ebay.com/ebaymotors/Subaru-I ... 43a2c4e0f9
Funny thing about the Walbro fuel pump, some vendors' pics show a 90* angle strainer and others show the strainer at a slight angle to the pump.
I installed a Walbro 255 pump (GS 341 with installation kit) some years ago in my ss and it really is a bolt-on operation. And I never had any fuel starvation problem. The sock filter/strainer was just at a slight angle to the fuel pump.
Re: Power loss around sharp corners
Posted: Sun Jul 24, 2011 1:10 am
by SiCkSTi04
-Solved- The stock fuel pump filter fell off inside the tank so it wasn't getting all the fuel needed which caused fuel cut around corners
Check my other thread for pictures
http://bbs.legacycentral.org/viewtopic. ... 6&start=50
I replaced the pump & filter with a walbro with no more issues. thanks guys!
Re: Power loss around sharp corners -Solved-
Posted: Sun Jul 24, 2011 5:06 am
by 93Leg-c
It's great to know you've solved the problem! Happy driving!! Thanks for the link also!
Re: Power loss around sharp corners
Posted: Mon Jul 25, 2011 9:16 pm
by sqc151
sqc151 wrote:my 01 obs did this to. changed the fuel pump, fuel filter, plugs... nothing changed.
mine ended up being frozen front calipers.
Re: Power loss around sharp corners
Posted: Tue Jul 26, 2011 7:17 pm
by Omega79
sqc151 wrote:sqc151 wrote:my 01 obs did this to. changed the fuel pump, fuel filter, plugs... nothing changed.
mine ended up being frozen front calipers.
