Welcome to the North American Subaru Impreza Owners Club Monday September 1, 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 > Factory 2.0L Turbo 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 08-16-2005, 09:13 PM   #1
galacticWRX
Scooby Newbie
 
Member#: 91841
Join Date: Jul 2005
Chapter/Region: SCIC
Location: So. Cal
Vehicle:
2004 Subaru REX
Corner Exit Speeds :)

Default Major Idle problem ? Help ?

Ok guys this one is not only defying my knowledge but also every Subaru tech in SoCal.
I have a 2004 WRX Protuned by Harman and this is my problem:

I have a nasty idle problem where it rises to about 1500rpm when cold then stumbles down to about 500 or even 450 rpms. Sometimes it even stalls. (Scary especially when your doing 60mph on the freeway.) The car does it at any temperature and in any condition. Also there is a large amount of hesitation when pressing the gas anywhere below 4,000rpms. It is not throwing a cell code, but that may be attributed to the Cobb Accessport.

All bolt-ons are done except for the turbo and fuel upgrades.

The dealer will cover it under warranty but they can't find out whats wrong. They think it is a MAF sensor and I think it could be the IAC sensor. Since just 2 weeks ago the coolant line going into the IAC came off and splattered coolant everywhere. I reconnected it ASAP but ever since then I have had problems.

Please any help would be appreciated at this point. I am tired of losing sleep over this. Need those pro's out there to lend a hand please....
* Registered users of the site do not see these ads.
galacticWRX is offline   Reply With Quote
Old 08-16-2005, 09:27 PM   #2
JRSCCivic98
Scooby Specialist
 
Member#: 67080
Join Date: Jul 2004
Default

I was going to point my finger at a coolant bypass mod done to the TB, but then I saw you indicate the hose comming off and whatnot. Since coolant can be somewhat of a pain for electrical equipment I would check the harness connector to the IAC first and make sure it's not coroded or covered in coolant. Next if cleaning that doesn't do anything I would seriously check for any leaks you may have on a vacume hose arround the IAC... when you plugged the IAC coolant hose back in you could have knocked something loose. Last, I would make sure you have the latest Harman map tune backed up and I would unmarry your AP to see if that does anything in stabalizing the idle (to rule out aftermarket EM) or if that helps in generating a CEL since it'll be running on the OEM engine code for diags.

On a side note... you haven't done the 05 firmware update on your 04 AP have you? There are issues with 05 firmware on 04 ecus, but it's not exactly like you're describing the problem. Stallouts are part of that problem for the majority.
JRSCCivic98 is offline   Reply With Quote
Old 08-16-2005, 09:57 PM   #3
galacticWRX
Scooby Newbie
 
Member#: 91841
Join Date: Jul 2005
Chapter/Region: SCIC
Location: So. Cal
Vehicle:
2004 Subaru REX
Corner Exit Speeds :)

Default

Ok what happens when the coolant is bypassed into the tb. Is it when the top hose to the IAC is connected to the lower hose coming out of the TB. If so what problems does this make..?? May have some coolant in intake??? I may have done this not sure??? Thanks for help...
galacticWRX is offline   Reply With Quote
Old 08-16-2005, 10:39 PM   #4
JRSCCivic98
Scooby Specialist
 
Member#: 67080
Join Date: Jul 2004
Default

No coolant will go into the intake by disconnecting this. (Don't panic) What the coolant is there to do is flow through the tb to keep it from possibly freezing in extreme winters. However, the IAC also tends to feed off this supply line (haven't actually looked at my wrx, but all other cars are like this) and it controls how much air to let in during warmup of the engine to keep the engine from dying out. When you bypass this coolant flow the IAC cannot tell what the coolant temp is at and can't properly actuate the right amount of air and sometimes (not always) causes the engine to have an erratic idle such as you describe.
JRSCCivic98 is offline   Reply With Quote
Old 08-17-2005, 01:23 AM   #5
galacticWRX
Scooby Newbie
 
Member#: 91841
Join Date: Jul 2005
Chapter/Region: SCIC
Location: So. Cal
Vehicle:
2004 Subaru REX
Corner Exit Speeds :)

Unhappy

Thanks... but I put the hoses back and it is still idling eradic even after I reversed the process. Is the sensor wiped out or can they just clean it?
I dont know whether it is bad to drive with this poor idle. Should I get it towed tomarrow? What else could have been affected and are there any other possible fixes?

Thanks for being helpful.
galacticWRX is offline   Reply With Quote
Old 08-17-2005, 07:44 AM   #6
Unabomber
Big Ron
Moderator
 
Member#: 18062
Join Date: Apr 2002
Chapter/Region: MAIC
Location: I can save you a ton of cash
Vehicle:
on car parts so PM
me b4 j00 buy

Default

Go to the service & maintenance forum. Perform the procedure that is a sticky in that forum about cleaning the IAC. Once you are done and it fixes your problem, post back praising the knowledge of the Unabomber.
Unabomber is offline   Reply With Quote
Old 08-17-2005, 09:48 AM   #7
JRSCCivic98
Scooby Specialist
 
Member#: 67080
Join Date: Jul 2004
Default

He has an 04 with a dirty IAC already...

Besides, it sounds like he doesn't like working on his own car... so I'm betting it's going back to the dealership where all the idiots live.
JRSCCivic98 is offline   Reply With Quote
Old 08-17-2005, 10:38 AM   #8
Unabomber
Big Ron
Moderator
 
Member#: 18062
Join Date: Apr 2002
Chapter/Region: MAIC
Location: I can save you a ton of cash
Vehicle:
on car parts so PM
me b4 j00 buy

Default

Dirty IACs happen, it did on my 04 several months ago. I know better now and am rockin' the OEM paper filter. Paper > Foam/high flow filters at filtration.
Unabomber is offline   Reply With Quote
Old 08-17-2005, 11:36 AM   #9
galacticWRX
Scooby Newbie
 
Member#: 91841
Join Date: Jul 2005
Chapter/Region: SCIC
Location: So. Cal
Vehicle:
2004 Subaru REX
Corner Exit Speeds :)

Have a Nice Day?

I love working on my own car infact I did all the mods so far except tuning. My approach to this situation is: If the dealer will fix it under warranty then let them try. If they will put a new sensor on then I am in good shape. I have tried to locate the problem but couldn't find it so I came to you guys the experts... I dont know what other problems this could have caused but any info on the consiquences would be appreciated.

Im on my way to the dealer for the warranty work hopefully its quick. I Will post back on the outcome....

Thanks again,
galacticWRX is offline   Reply With Quote
Old 08-17-2005, 01:20 PM   #10
AQ Motorsports
Former Vendor
 
Member#: 60836
Join Date: Apr 2004
Chapter/Region: SCIC
Location: Torrance, CA
Vehicle:
2006 Mod Class STI
TIMEATTACK!!

Default

Anytime you have a funky idle or hesitation, the first thing you need to look for is a vacuum leak.

Check every hose coming off your intake manifold. If you notice that the hesitation clears up when you floor the car, that's a good indication that it is a hose issue (once the car is in open loop - it doesn't try to compensate anymore).

Is your boost steady? When did the problem start?

Regards,

Dan
AQ Motorsports is offline   Reply With Quote
Old 08-17-2005, 09:05 PM   #11
galacticWRX
Scooby Newbie
 
Member#: 91841
Join Date: Jul 2005
Chapter/Region: SCIC
Location: So. Cal
Vehicle:
2004 Subaru REX
Corner Exit Speeds :)

Unhappy

No it feels like the car is jurky and hesitating in low rpms and then almost stalls. Up top it feels pretty smooth. I think boost is fluctuating but I cant tell. I am going to flash it back to stock then see if it stops. The dealer claimed it was an ecu problem because of "modification" or an unseen hose leak.
I hope it isn't running to lean...
I may stop by if I cant find the problem tomarrow.
Thanks,
galacticWRX is offline   Reply With Quote
Old 08-18-2005, 11:56 AM   #12
galacticWRX
Scooby Newbie
 
Member#: 91841
Join Date: Jul 2005
Chapter/Region: SCIC
Location: So. Cal
Vehicle:
2004 Subaru REX
Corner Exit Speeds :)

Impreza WRX

So after all that time spent at the dealer they gave it back to me with the same exact problem. They claimed they checked Manifold pressure, IAC sensor, MAP sensor, MAF sensor, and the knock sensor. Then they proceeded to tell me that the tuning that I did cause this problem.

So after limping the car home I decided to let it cool then go to work and maybe tear the engine apart. First I reset the ecu back to the stock map and it continued having the same issue. So i removed the intercooler and voulah... The BOV hose was disconnected from the Turbo inlet completely. So I fixed the prob tightened everything and put it back together. NO IDLE PROBLEM NOW.... ....

I called the dealership and gave then a forcefull lecture on how they have had the car for over 2 days and couldn't find the issue. So then I get the car and spend 10-15 minutes taking it apart and find exactly what wrong.
Are they idiots????
Also told them that they gave me a line of **** about checking the manifold pressure. They should have seen that there was a leak and the fluctuation in MAP readings. My EM wasn't letting the CEL go off so they couldn't diagnos the prob. Thats what they claimed.

Oh well the trip to the dealer wasn't a total loss. They replaced my flywheel, clutch, and pressure plate under warranty. Feels smooth as butter.
galacticWRX is offline   Reply With Quote
Old 08-18-2005, 01:12 PM   #13
JRSCCivic98
Scooby Specialist
 
Member#: 67080
Join Date: Jul 2004
Default

Good for you.
JRSCCivic98 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
PE800 idle problems! Help! GMTarkin Engine Management & Tuning 23 06-11-2006 12:12 AM
Major Engine Problem, help! popnGEAR Normally Aspirated Powertrain 6 10-03-2004 10:05 PM
Major Engine Problem, help! popnGEAR Factory 2.5L Turbo Powertrain 0 10-02-2004 02:38 PM
TEC 3 idle problem? Help hayscoob Engine Management & Tuning 12 07-23-2004 10:49 AM
Idling problem. HELP!! Bulletken Newbies & FAQs 3 11-12-2001 05:27 PM


All times are GMT -4. The time now is 03:57 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.