Welcome to the North American Subaru Impreza Owners Club Friday August 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 > 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 06-20-2013, 01:49 AM   #1
ksingh2463
Scooby Newbie
 
Member#: 247537
Join Date: May 2010
Chapter/Region: MWSOC
Location: KCMO
Vehicle:
02 MBP WRX

Default 2003 Idle/Drivability Problem

I recently swapped out the engine in my 2003 WRX (over 200K mi) with a high mileage replacement unit in good condition. It started up just fine the first time with no issues or CELs.

After a brief test drive, I fired the engine back up and it began to idle high. P0519 CEL (Idle Control System ***********Malfunction: Engine keeps running at higher revolution than specified idling revolution) popped up on the dash. At idle, the engine speed would occasionally oscillate between 1250 and 2000RPM and sometimes drop very low and run rough.

I then decided to take it out for another test drive to see if the problem would go away. Right away, I could feel that driveability had gone to complete ****, especially after engaging the clutch and giving it some gas in first gear. Going from partial throttle to off throttle in gear also doesn't feel as it should.

After doing some digging and research on the problem, I decided to clean out the IACV (this is the same IACV that was on the previous engine and never caused an idling problem). Didn't help any so I replaced it with another one. That also didn't solve anything. I then checked the throttle cables for excessive tension and they had plenty of slack. After doing all this, I tried swapping out the Neutral Safety Switch. I tried two switches from two different perfectly running cars and none helped solve the problem. I've also reset the ECU many times and that didn't help either.

Has anyone had a similar problem? If so, can you tell me what I'm doing wrong because I feel like I've tried just about everything. I've added a video below of how the car idles. Notice how the engine speed rises upon starting and then falls. In the video it stays around 1500 RPM but occasionally it will begin to oscillate.

Any insight or help would be extremely appreciated. Thanks in advance!

* Registered users of the site do not see these ads.
ksingh2463 is offline   Reply With Quote
Old 06-20-2013, 03:52 PM   #2
ToddMcF2002
Scooby Specialist
 
Member#: 135007
Join Date: Dec 2006
Location: Plymouth, MA
Vehicle:
2014 STi Hatch
Crystal Black Silica

Default

Did you change the IACV gasket? I would think a vacuum leak there of any size would create havok. Maybe try cleaning your MAF or swap one out as a test. BTW when you resolve this *please* post the solution!
ToddMcF2002 is offline   Reply With Quote
Old 06-20-2013, 04:31 PM   #3
GulfCoastMotorworks
Former Vendor
 
Member#: 358317
Join Date: Jun 2013
Chapter/Region: South East
Location: Bonita Springs, FL
Vehicle:
6266 Built Bugeye
GulfCoastMotorWorks.com

Default

We had a car recently go through 3 used IACVs until one was operational......it happens.
GulfCoastMotorworks is offline   Reply With Quote
Old 06-20-2013, 05:10 PM   #4
fastnoypi
Scooby Specialist
 
Member#: 6886
Join Date: May 2001
Chapter/Region: Tri-State
Vehicle:
MY01 EJ207 HTA35r
nothing to see, i'm stock

Default

did the rpm oscillation go away once you came up to operating temp?
If you didn't wait, the IACV is doing what it is supposed to.
Also double check your IACV gasket install to make sure it didnt get pinched. A pinched gasket can also cause rough idle.
fastnoypi is online now   Reply With Quote
Old 06-20-2013, 07:20 PM   #5
Blktrax
Scooby Newbie
 
Member#: 220971
Join Date: Aug 2009
Chapter/Region: South East
Location: Havelock, NC
Vehicle:
2002 WRX 209K Mi.
2012 Impreza Sport Ltd.

Default

unplug the maf, start engine,

if it idles smooth-er, maf is toast.

IACV is a response to a closed throttle condition, to manage what the maf sees.

also try disconnecting your throttle cables, if either the pedal or cruise cable is too tight, it wont allow the throttle to close completely, causing the same code.


These of course assume no vacuum leaks.
Blktrax is offline   Reply With Quote
Old 06-21-2013, 09:42 AM   #6
ksingh2463
Scooby Newbie
 
Member#: 247537
Join Date: May 2010
Chapter/Region: MWSOC
Location: KCMO
Vehicle:
02 MBP WRX

Default

I made sure that the IACV gasket was installed correctly and I'm pretty confident that the IACV isn't the problem. Throttle cables have been loosened and it didn't make a difference. The MAF is the same one that came off the perfectly running engine and I believe it to be in good condition.

I believe I have an intake/vacuum leak somewhere. Before dropping the new motor into the car, I did swap out the throttle body but didn't change the gasket since it looked good. Could not changing the gasket cause a leak? Also will an intake leak on the turbo outlet hose cause an idling problem?
ksingh2463 is offline   Reply With Quote
Old 06-21-2013, 10:57 AM   #7
StarburstAutos
Scooby Newbie
 
Member#: 344253
Join Date: Jan 2013
Location: barberton ohio
Vehicle:
03 WRX Sedan
primer black

Default

thinking vacuum leak check the tb gasket that you didn't change. good start there then you can do the spray trick to see if there is a leak just use a can of carb cleaner or brake cleaner if you don't have carb cleaner and when you hit the spot with the leak the idle will change hard. this will at least get you in the right area for a vacuum leak.
StarburstAutos is offline   Reply With Quote
Old 07-02-2013, 03:49 AM   #8
ksingh2463
Scooby Newbie
 
Member#: 247537
Join Date: May 2010
Chapter/Region: MWSOC
Location: KCMO
Vehicle:
02 MBP WRX

Default

Problem solved. No vacuum/intake leaks were found. Replaced the IACV for the third time and the issue was resolved. Just my bad luck with these things. Both of the ones I used previously were bad.

Thanks for the help guys!
ksingh2463 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


All times are GMT -4. The time now is 10:33 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.