Welcome to the North American Subaru Impreza Owners Club Wednesday August 20, 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 with bolt-on Forced Induction 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 04-24-2002, 10:04 PM   #1
giulio
Scooby Newbie
 
Member#: 16040
Join Date: Mar 2002
Location: NY USA
Vehicle:
1998 Impreza RS
Supercharged

Default No a/f cycling at idle

Whats up fellas

Recently I changed my clutch slave cyl. That fixed my low pedal problem, but that same night i got idle problems.

It idles rough, once the car is warm and rpms drop to 700. sometimes almost stalling, dropping to 500 then catching up to 850 and back to 700.

TPS is working fine. 0.0%
AFL is fine. 0.8% (98MY)
Vac is fine. 18-20mmHg
All Cylinders are firing
what isN'T fine is the A/F...

it's not cycling anymore at idle. While cruising it's working fine though. And at high throttle it's fine too- nothing is out of the ordinary except at idle.
I disconnected the boost guage and PFR from the lines, pretty much putting fueling back to stock. Reset the ECU. Started it up... same thing. I checked all the vacuum lines... they're all fine.

Any ideas?
Would an ODBII scan find out what's up? There's not CEL.

thanks in advance,
giulio
* Registered users of the site do not see these ads.
giulio is offline   Reply With Quote
Old 04-24-2002, 11:01 PM   #2
Graham
Scooby Specialist
 
Member#: 11931
Join Date: Nov 2001
Location: Winter Park, FL/ SMU @ Dallas,
Vehicle:
2001 2.5 RS Turbo
257/FMIC/T3-T04S

Default

I would say maybe a bad MAF reading at low RPM. Also, what your fuel pressure at idle? If you have a high pressure pump, like most of the Walbro's out there, long term high baseline fuel pressure could be a catalyst for something like this, just a thought.

Also, and I have mentioned this in previous posts, but what about your fuel filter going bad? They do have a life expectancy you know.

Hope you get it figured out, sitting at traffic lights with your foot pumping the throttle sucks.

Graham
Graham is offline   Reply With Quote
Old 04-24-2002, 11:27 PM   #3
Legacy GTR
Scooby Specialist
 
Member#: 9316
Join Date: Aug 2001
Location: Litchfield Park, AZ
Vehicle:
1997 Legacy GT
14.767@93.54

Default

Is it staying constent at one place on the A/F meter? Or is it not on at all. Check and see what voltage your at during idle. mabe it's a little low.
Mike
Legacy GTR is offline   Reply With Quote
Old 04-25-2002, 12:35 AM   #4
Aphex
Scooby Specialist
 
Member#: 146
Join Date: Aug 1999
Location: Wahcheeta, KS
Vehicle:
'05 Legacy GT
Silver

Default

damn, another one, same thing with me, I'll check my A/F meter tomorrow when it does it to see what it's doing, but the idle characteristics is the same, fuel filter replaced shortly before it happened.
Aphex is offline   Reply With Quote
Old 04-25-2002, 01:38 AM   #5
subachad
Scooby Specialist
 
Member#: 8488
Join Date: Jul 2001
Location: Sin City
Vehicle:
1993 Impreza GCStyle
Teal

Default

Are you sure it's not just cold? When the o2 is cold, it's not going to cycle.

If it's doing it after a drive, perhaps you should relocate the o2 sensor.

Chad
93 1.8T
subachad is offline   Reply With Quote
Old 04-25-2002, 04:05 PM   #6
Aphex
Scooby Specialist
 
Member#: 146
Join Date: Aug 1999
Location: Wahcheeta, KS
Vehicle:
'05 Legacy GT
Silver

Default

been driving around today and I get the exact same symptoms as gulio, A/F cycles at cruise, but not at idle.

what the heck does that mean?

eli
Aphex is offline   Reply With Quote
Old 04-25-2002, 09:03 PM   #7
STiTuner
Scooby Specialist
 
Member#: 5778
Join Date: Apr 2001
Chapter/Region: South East
Vehicle:
09 135i
Jet Black

Default

just tell people you cam cams with big lobes in your car and no one will ask whats up

Brad
STiTuner is offline   Reply With Quote
Old 04-26-2002, 02:28 PM   #8
giulio
Scooby Newbie
 
Member#: 16040
Join Date: Mar 2002
Location: NY USA
Vehicle:
1998 Impreza RS
Supercharged

Lightbulb

Thanks for the help everyone, much appreciated.

air meter readings are normal, about 0.8% at idle. usually it's .9 or 1.0... does .1% really make that much of a difference? i get a little over 50% at 6500rpm full throttle.
the walbro pump is only a year old and sounds fine. At cruise and full throttle everything is fine.
fuel filters were changed 30k miles ago.
the a/f guage isnt even lighting up the first led. it's off the chart, low.
Cold start it idles fine, 1500 rpm. when it drops to 700 it gets rough.

Well I finally gave up... brought it to the local mechanic to have it checked out (please forgive me haha).
He says there's a small leak where the SC is mounted to the intake manifold adapter. so some air is leaking out and screwing up the reading. but it's not enough to matter at cruise or boost.
I think he might be right. The rimmer instructions said to use RTV sealer and so i always have. but this time i didnt let it sit and cure overnight (totally forgot). i just bolted it on and full boosted down the road. oops! I guess it blew some sealer out of the junction. It was that very next drive when this condition started... and just got worse every day so far.

So... guess what i'll be doing saturday morning... again. I'm getting pretty good at this now. runnin out of bandaids though =/
Hopefully the mech is right and i'll be back to normal sunday morning.

Eli,
Check every single vacuum hose. i wonder if you can put a drop of water over fittings and see if it gets sucked in (leak). good luck with it!
giulio is offline   Reply With Quote
Old 04-26-2002, 08:09 PM   #9
Aphex
Scooby Specialist
 
Member#: 146
Join Date: Aug 1999
Location: Wahcheeta, KS
Vehicle:
'05 Legacy GT
Silver

Default

thanks I'll check into it, it did seem to start happening after I put my IC on, however I've had an air leak in my second air box before when I was N/A and it was totally different from what it happening now, I'll check it out though.

eli
Aphex is offline   Reply With Quote
Old 04-27-2002, 10:55 AM   #10
PunKidd
Scooby Specialist
 
Member#: 8533
Join Date: Jul 2001
Location: Austin TX
Vehicle:
2002 2.5 RS-T
LudeSpeed S. III W/ FMIC

Default

Just a thought, but getting water inside a vacume line does not sound like a great idea to me.
PunKidd is offline   Reply With Quote
Old 04-27-2002, 12:06 PM   #11
ColinL
Scooby Guru
 
Member#: 114
Join Date: Jul 1999
Chapter/Region: MWSOC
Location: Wichita, KS and Whoring, OT
Vehicle:
'03 Evo, Rice White
'01 Erion CBR 929

Default

true, a smarter thing to use is starting fluid.
ColinL is offline   Reply With Quote
Old 04-29-2002, 09:16 AM   #12
giulio
Scooby Newbie
 
Member#: 16040
Join Date: Mar 2002
Location: NY USA
Vehicle:
1998 Impreza RS
Supercharged

Exclamation

What the hell was i thinking with that water comment...


I resealed the mating parts. But I can't tell if it worked or not. The rpms won't drop below 1300 now.

bypass valve is in the correct position.
a/f is cycling normally again.
throttle is 0.0%
afl is well over 1%.
CEL is on.

I'm thinking 2 things.

A) air is being sucked in before the throttle body
- Maybe something's broken with that valve that handles idling at 0 throttle ( forgot the name... pvc? pcv? )

B) timing is being raised causing really high idle.
- Ecu or J&S fried?

I don't think it's a fuel problem. I tried lowering it with the afc but the rpms didnt go down. I also tried raising it. The car just compensates and goes back to 1300.

i'm getting sick and tired of this.
the rx-8 is looking better every day.

g
giulio is offline   Reply With Quote
Old 04-29-2002, 09:35 AM   #13
Graham
Scooby Specialist
 
Member#: 11931
Join Date: Nov 2001
Location: Winter Park, FL/ SMU @ Dallas,
Vehicle:
2001 2.5 RS Turbo
257/FMIC/T3-T04S

Default

So you have resealed it and the car is still doing this?

Graham
Graham is offline   Reply With Quote
Old 04-29-2002, 02:34 PM   #14
giulio
Scooby Newbie
 
Member#: 16040
Join Date: Mar 2002
Location: NY USA
Vehicle:
1998 Impreza RS
Supercharged

Default

No, it's a different problem now.

Before the car idled at normal rpm, very rough, then droped to 400... bounced to 900, then leveled off at 700 again. (sometimes it wouldnt bounce back, and just stall) There was no CEL.

Now it doesnt go below 1300rpm, smooth, and i have a CEL.

Since I have a CEL i might as well have the code pulled.

Situations suck when it's your commuter car.
g
giulio 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
No heat at Idle?? northpolerex Factory 2.0L Turbo Powertrain 14 12-24-2009 07:45 PM
Help no power steering at idle. Porkchop-WRX Brakes, Steering & Suspension 9 10-09-2006 10:49 AM
Why no boost at idle? vipernj Factory 2.0L Turbo Powertrain 60 12-15-2005 01:52 PM
No heat at idle, only when moving, and long warm up period? Need4Boost Factory 2.0L Turbo Powertrain 18 12-01-2002 12:01 PM
Rev at idle, why no boost? Ethan Factory 2.0L Turbo Powertrain 4 07-24-2001 06:35 PM


All times are GMT -4. The time now is 08:02 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.