Welcome to the North American Subaru Impreza Owners Club Thursday March 28, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)

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.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 01-22-2004, 05:06 AM   #1
Big Turkey
Scooby Specialist
 
Member#: 32118
Join Date: Jan 2003
Location: Houston, TX
Default Crazy AFR's

I was out with a couple of high-rollin' domestics tonight playing around because I just poured in some C16 for some fun. I ended up running a LS1 Formula Firebird on slicks in the back, skinnies up front, no exhaust, race gas and a decent shot of gas. We went from a 20 punch and I ended up putting about 2-3 on him.. I have a vid I'll link soon, but that isn't the point of the post. Well about end of 3rd gear, my motor pops and detonates.

So I pull into the gas station and check everything.. seems okay. I change maps to a more conversative one. I go for a test run. 50 punch, 3rd gear. The turbo screams, and the exhaust is deafening.. but I'm not going anywhere. I look at the boost gauge, 1.7bar. ***?! I look down at the wideband.. 16.1:1 AFR!!! I let off. I turn down the boost. Stand on it. Same thing. 16:1. I turn off the boost controller and switch my map to my pump gas map.. which is EXTREMELY conversative especially on C16, then I floor it. 15.5:1. Something's wrong. The car kept buckin' and popping and hesitating. No bueno.

Even at wastegate boost (about 12-13psi, it's my secret sauce wastegate ), the AFR's would jump straight to 15:1-16:1 on my wideband. I know it's the wideband because at cruise and partial throttle everything seems normal.

This leads me to believe that my front air/fuel 02 sensor went out on me. Probably clogged up from all that lead. What do you guys think?
* Registered users of the site do not see these ads.
Big Turkey is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 01-22-2004, 06:59 AM   #2
recursian
Scooby Newbie
 
Member#: 9976
Join Date: Sep 2001
Location: Atlanta, GA
Vehicle:
2003 Subaru WRX
Blue

Default

Could be any number of things. Is it running right in closed loop, with your wideband displaying around 14.2? I would check the maf sensor first. Then check the fuel pressure. The front O2 sensor should not impact full throttle mixtures as the system is in open loop. The only way it might do that is by using long term fuel trim offset. I haven't seen any evidence of that happening in my experimentation.
recursian is offline   Reply With Quote
Old 01-22-2004, 09:26 AM   #3
8Complex

Moderator
 
Member#: 922
Join Date: Feb 2000
Chapter/Region: MWSOC
Location: Schaumburg, IL
Vehicle:
16 WRX (white)
04 FXT (red)

Default

What year is your car?
8Complex is offline   Reply With Quote
Old 01-22-2004, 10:02 AM   #4
davidm_sh
Scooby Specialist
 
Member#: 5994
Join Date: Apr 2001
Location: Fort Collins, CO
Vehicle:
2004 Impreza WRX STi
Java Black

Default

Check your vacuum line running to your FPR.
davidm_sh is offline   Reply With Quote
Old 01-22-2004, 10:07 AM   #5
Big Turkey
Scooby Specialist
 
Member#: 32118
Join Date: Jan 2003
Location: Houston, TX
Default

My car is a 2003. I'll check that out.

Well *** do you know. Sure enough, it came off. How did you know?
Big Turkey is offline   Reply With Quote
Old 01-22-2004, 10:12 AM   #6
scoobystas
Scooby Specialist
 
Member#: 26568
Join Date: Oct 2002
Chapter/Region: NESIC
Location: Brighton, Mass
Vehicle:
2003 Yellow Bugeye
Version 8-Vf37

Default

FRP is located on the passenger side of the manifold right? I put a small clamp on mine because it was the spot i use to run my boost guage off.
scoobystas is offline   Reply With Quote
Old 01-22-2004, 10:47 AM   #7
jblaine
Scooby Guru
 
Member#: 8512
Join Date: Jul 2001
Chapter/Region: South East
Location: St. Pete, FL
Vehicle:
2002 WRX chassis...
stage-infinity.com

Default

Quote:
Originally posted by Big Turkey
How did you know?
Member#: 5994
jblaine is offline   Reply With Quote
Old 01-22-2004, 11:24 AM   #8
worry
Scooby Newbie
 
Member#: 13461
Join Date: Dec 2001
Location: UK, bbs.22b.com
Default

I had the same problem a few years ago. The rolling road operator had T'd a boost gauge into the FPR line for a power run and had not properly secured (with a zip-tie or similar) the FPR reference line back onto the manifold afterwards. The first chance I had to run some boost, the unsecured FPR line blew off and the engine let go within seconds, having melted two pistons.

It sounds as though you may have been more lucky, in that your engine is still running. I hope you haven't sufffered any significant damage to the internals in the process. I'll cross my fingers for you.
worry is offline   Reply With Quote
Old 01-22-2004, 12:48 PM   #9
Big Turkey
Scooby Specialist
 
Member#: 32118
Join Date: Jan 2003
Location: Houston, TX
Default

I think the reason why I didn't suffer too much damage is because I had C16 in the tank. And I was running off my pump gas map so that it was extremely rich. Thank goodness. The motor seems fine. I just did a quick pull through the gears and it pulls as hard as before.
Big Turkey is offline   Reply With Quote
Old 01-22-2004, 12:48 PM   #10
Big Turkey
Scooby Specialist
 
Member#: 32118
Join Date: Jan 2003
Location: Houston, TX
Default

Quote:
Originally posted by scoobystas
FRP is located on the passenger side of the manifold right? I put a small clamp on mine because it was the spot i use to run my boost guage off.
Mine is located on the driver's side because I have Perrin Fuel Rails.
Big Turkey 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
ideal afr's vs. rpm kenlee Engine Management & Tuning 11 03-30-2005 01:16 AM
Ignition Timing and AFR's 555 Engine Management & Tuning 2 01-02-2005 04:02 PM
AFR's hondaeater69 Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 2 10-15-2004 08:06 PM
what are some normal healthy AFR's for a stge 4 wrx? blackie Engine Management & Tuning 3 10-01-2004 04:31 PM
Spiraling AFR's when pumping the brakes at idle... TexRex2002 Engine Management & Tuning 5 06-30-2004 12:57 AM

All times are GMT -4. The time now is 10:21 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.