Welcome to the North American Subaru Impreza Owners Club Tuesday July 29, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 08-14-2006, 06:17 PM   #1
Necromancer
Scooby Specialist
 
Member#: 477
Join Date: Oct 1999
Location: Vancouver
Vehicle:
GC4 -> GGA -> GM6
Yeah, that's about right.

Default Whine at WOT - fuel pump or ...???

OK here we go again... I've been trying to diagnose this problem for literally years now and the chance has finally come to pull whatever parts I might need.

Symptoms:
- High-pitched whine under high load / WOT (kind of like "shhhh")
- Car stumbles and hesitates after being driven hard for a while (running lean --> overheating?)
- High NOx reading at emissions check (seems lean to me)
- Otherwise seems to run normal (never throws a CEL)

I pulled the fuel pump and the strainer sock looked perfectly clean. Is it worth replacing the thing???

Any other suspects?
Necromancer is offline   Reply With Quote
Old 08-14-2006, 06:32 PM   #2
Master2192
RIP 10/12/83 to 02/10/08
Scooby Specialist
 
Member#: 83254
Join Date: Mar 2005
Chapter/Region: NWIC
Location: Roy, Washington
Vehicle:
98 2.5 RS
04 WRX

Default

What year car? I am not sure how you could test it. Maybe put in a fuel pressure gauge and somehow test the maximum pressure the pump will hold? You may just want to replace it based on its age and see if it fixes your problem.
Master2192 is offline   Reply With Quote
Old 08-14-2006, 08:14 PM   #3
Tim Sanderson
Scooby Guru
 
Member#: 6486
Join Date: May 2001
Chapter/Region: MWSOC
Location: S.E. wisconsin
Vehicle:
00 Impreza 2.5 RS
Blue Ridge Pearl

Default

How many miles on the vehicle? When was the last time you changed your fuel filter?

I would test the fuel pressure with and without the vacuum line on the fuel pressure regulator.
Tim Sanderson is offline   Reply With Quote
Old 08-15-2006, 01:09 PM   #4
msm98lw
Scooby Newbie
 
Member#: 55849
Join Date: Feb 2004
Location: Danbury, CT
Vehicle:
2000 Impreza 2.5RS
'97 legacy GT wagon

Default

My '97 LGT (95K) has a whistle at wOT that I thought was a vacuum leak, but the dealer told me it was a failing muffler baffle.
msm98lw is offline   Reply With Quote
Old 08-16-2006, 06:25 AM   #5
Necromancer
Scooby Specialist
 
Member#: 477
Join Date: Oct 1999
Location: Vancouver
Vehicle:
GC4 -> GGA -> GM6
Yeah, that's about right.

Default

Thanks for the responses so far. The car is an '01 2.5RS with about 70K miles. Fuel filter, spark plugs, and lots more are new.

I guess the fuel pressure test would be the obvious thing to do -- not exactly easy but I'll give it a try.

An exhaust leak wouldn't normally cause this kind of lean situation, right?

Anyway, thanks for the thoughts -- I'll keep the board updated with where this is going.
Necromancer is offline   Reply With Quote
Old 08-16-2006, 08:35 AM   #6
Nemesis Digital
Scooby Newbie
 
Member#: 119579
Join Date: Jul 2006
Chapter/Region: South East
Vehicle:
2004 WRX Wagon
San Remo Red

Default

Quote:
Originally Posted by Necromancer
Thanks for the responses so far. The car is an '01 2.5RS with about 70K miles. Fuel filter, spark plugs, and lots more are new.

I guess the fuel pressure test would be the obvious thing to do -- not exactly easy but I'll give it a try.

An exhaust leak wouldn't normally cause this kind of lean situation, right?

Anyway, thanks for the thoughts -- I'll keep the board updated with where this is going.

An exhaust leak large enough could allow more Oxygen to cause a false reading. My wideband read higher AFRs when I had a leak.
Nemesis Digital is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
fuel problem, is it the fuel pump or FPR? Unabomber Factory 2.0L Turbo Powertrain 12 02-24-2012 04:42 PM
WTB:OE Fuel Pump or Walbro Fuel Pump hey1 Private 'Wanted' Classifieds 2 02-20-2007 08:58 PM
Wierd whine at wot, like a supercharger Supra95 Newbies & FAQs 43 05-27-2006 02:16 AM
Torque mods: Do I need a bigger fuel pump or TMIC with a vf24 upgrade? chazbott Factory 2.0L Turbo Powertrain 7 12-05-2004 11:39 AM
high pitched sound at speed; fuel pump?? Dave G Outback Forum 11 11-22-2004 10:18 PM


All times are GMT -4. The time now is 09:21 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.