Welcome to the North American Subaru Impreza Owners Club Sunday October 26, 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 04-23-2002, 11:20 PM   #1
PRODRIVEN
Scooby Specialist
 
Member#: 111
Join Date: Jul 1999
Location: Cincinnati - San Diego
Vehicle:
1999 Impreza 2.5 RS
EJtwentyfied -> '04 STi

Question Running extemely rich

My car (MY99 RS) is running extremely rich. It idles at about 500rpm then rises to 1000rpm and back down to almost zero until it revs back to about 1000k until it eventually dies if I sit at a red light to long. Black smoke also comes out the exhaust when it idles. You can even smell the gas fumes when driving behind me. I tried resetting the ecu but that didn't change anything. The only other changes recently have been a new fuel filter and pcv valve last week, but the problem only started a couple days ago. Anyone have any ideas what the problrm may be? Bad O2 sensor, MAF, burnt spark plugs (except thay are only about 2 months old)?
* Registered users of the site do not see these ads.
PRODRIVEN is offline   Reply With Quote
Old 04-23-2002, 11:51 PM   #2
Penphoe
Friendly Neighbourhood
Moderator
 
Member#: 269
Join Date: Sep 1999
Chapter/Region: VIC
Location: Burnaby, B.C., Canada
Vehicle:
2005 ABP LGT LTD BP6
00 Impreza RS GM6 RIP

Default 500 RPM???

Are you sure you're idling at 500 RPM? That seems a little low. If you look at the first line after the zero mark, it is the "medium" sized line, it is the 500 RPM line.

LaterZ!
Darren!!
Penphoe is offline   Reply With Quote
Old 04-24-2002, 12:08 AM   #3
wistful
Scooby Specialist
 
Member#: 745
Join Date: Jan 2000
Location: Royal Oak, MI
Vehicle:
2004 STi
Java Black Pearl

Default

kinda sounds like an o2 sensor. I think its getting weird readings and adjustingly accordingly. *Scratching head*.. dunno what else it might be. what MY do you have?

Don
wistful is offline   Reply With Quote
Old 04-24-2002, 01:23 AM   #4
Penphoe
Friendly Neighbourhood
Moderator
 
Member#: 269
Join Date: Sep 1999
Chapter/Region: VIC
Location: Burnaby, B.C., Canada
Vehicle:
2005 ABP LGT LTD BP6
00 Impreza RS GM6 RIP

Default

Quote:
Originally posted by wistful
kinda sounds like an o2 sensor. I think its getting weird readings and adjustingly accordingly. *Scratching head*.. dunno what else it might be. what MY do you have?

Don
He's got a MY99 - posted right up top!

O2 Sensor? Yah, you could be right. But wouldn't an O2 sensor going bad throw a CE light?

LaterZ!
Darren!!
Penphoe is offline   Reply With Quote
Old 04-24-2002, 03:04 AM   #5
HndaTch627
Scooby Guru
 
Member#: 6551
Join Date: May 2001
Chapter/Region: MWSOC
Location: Carol Stream, IL
Vehicle:
'01 GC8 Dinged STM
'09 Concours 14 ABS Black

Default

Quote:
Originally posted by Penphoe


He's got a MY99 - posted right up top!

O2 Sensor? Yah, you could be right. But wouldn't an O2 sensor going bad throw a CE light?

LaterZ!
Darren!!
yes...sounds like the typical goofy 99 MAF...unplug it and see if the car will idle normally. if it does you found your problem.

jeremy
HndaTch627 is offline   Reply With Quote
Old 04-24-2002, 10:34 AM   #6
PRODRIVEN
Scooby Specialist
 
Member#: 111
Join Date: Jul 1999
Location: Cincinnati - San Diego
Vehicle:
1999 Impreza 2.5 RS
EJtwentyfied -> '04 STi

Default

I was thinking o2 sensor, but that would throw a CE light which hasn't happened yet. I'll try and unplug the maf. Thanks guys.

Duncan
PRODRIVEN is offline   Reply With Quote
Old 04-24-2002, 11:09 AM   #7
imposter
Scooby Newbie
 
Member#: 10642
Join Date: Sep 2001
Location: Omaha Nebraska
Vehicle:
95 Impreza EJ22T
05 LGT, 96 Outback

Default

An O2 sensor going bad may not always throw a CEL right away, or even at all. I would start by cleaning the MAF w/ some electronic parts cleaner available at most auto parts stores, and then go to the O2 sensor. If you could get your hands on an OBD2 scanner that would really help.

-Jim
imposter is offline   Reply With Quote
Old 04-24-2002, 11:33 AM   #8
HndaTch627
Scooby Guru
 
Member#: 6551
Join Date: May 2001
Chapter/Region: MWSOC
Location: Carol Stream, IL
Vehicle:
'01 GC8 Dinged STM
'09 Concours 14 ABS Black

Default

9 times out of 10 a bad 02 will throw a code of some sort(usually a fuel trim code)

Jeremy
HndaTch627 is offline   Reply With Quote
Old 05-03-2002, 02:53 PM   #9
RageHardIntoTheBendies
Scooby Specialist
 
Member#: 1532
Join Date: May 2000
Location: Wnnipeg, MB, Canada
Vehicle:
1999 RS, Silverthorn
www.zucru.com

Default

Hey I have the same problem Was it the maf or the O2?
RageHardIntoTheBendies is offline   Reply With Quote
Old 05-07-2002, 02:38 PM   #10
BOY
NASIOC Supporter
 
Member#: 232
Join Date: Sep 1999
Chapter/Region: MWSOC
Location: Ft Wayne, IN
Vehicle:
99 RS-T RIP
02 Forster-S

Default

What happens when you turn on the AC? When I killed my MAF (ok, there was some life lift in it but not much) I had the exact same problem, rich running, rough idling, etc. When I turned on the AC the engine revs raised to ~800 and were stable. Now, mind you I've only blown one MAF throughout the entire 76k mi on the car (although I did blow up the shortblock too and I've been running a Weapon R CAI (with custom ram tubing dropped into the fender).
BOY is offline   Reply With Quote
Old 05-07-2002, 06:12 PM   #11
STi-Nane
Scooby Newbie
 
Member#: 18568
Join Date: May 2002
Location: Office Space, MD
Vehicle:
2006 7.5L Turbo
TypeR Rotary with Headers

Default

I had a similar problem with my MY01 and it turned out to be a short circuit in the Air/Fuel part of my ECU. It would idle really rough, almost to the point of stalling and sometimes the power would completely cut out during acceleration. I got terrible mileage too because the engine was running VERY rich at some times. Dealership fixed the ECU and it hasnt come back.
STi-Nane is offline   Reply With Quote
Old 05-07-2002, 06:19 PM   #12
karl_hungus
Scooby Newbie
 
Member#: 7507
Join Date: Jun 2001
Location: Windsor, Ontario
Vehicle:
2002 WRX Wagon
PSM

Default

This sounds almost exactly like the way my car was acting a few days ago. It turned out to be a bad front O2 sensor but I have a MY02...

I also got a CEL with 2 codes but they didn't show up right away:

Code #1 - running lean (which makes no sense since I'm usually running SUPER rich). I cleaned my exhaust tips about 10 days ago and already there is some carbon build up

Code #2 - faulty front O2
karl_hungus 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
Dyno'ed Car Today/HELP-Running Way Rich Bigmike Bay Area Impreza Club Forum -- BAIC 11 08-04-2002 05:32 PM
Dyno'ed Car Today/HELP-Running Way Rich Bigmike Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 0 08-02-2002 10:48 PM
Can running too rich for too long throw a CEL? Bighurt1 Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 7 03-26-2002 04:57 PM
My car is running really rich tcs007 Normally Aspirated Powertrain 24 01-08-2002 08:22 AM
My98 runs ultra rich up top even with intake...but i fixed it GregBolby General Forum Archive 4 03-26-2001 04:06 AM


All times are GMT -4. The time now is 03:09 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.