Welcome to the North American Subaru Impreza Owners Club Saturday July 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 06-10-2010, 06:06 AM   #1
WRX03
Scooby Specialist
 
Member#: 20744
Join Date: Jul 2002
Chapter/Region: MAIC
Location: Goodview, VA-SML
Vehicle:
05 Baja Regal Blue
03 WRX Little Red Wagon

Default Idle bouncing with air conditioner only

On my 05 Baja N/A only with the air conditioner on the rpm's will bounce erratically 3-6 times when you fully let off the throttle (either clutch in or out). This is a fast snap of the rpm's bouncing between 750 to 2000rpm oscillating about 1 second reving an 1 second off.
Another sympton with the air and cruise control on when the cruise decelerates the engine falls flat and snaps back on (neck jerks-not as smooth between on and off throttle).
Once again this is only with the air on and severe bouncing of the rpm's.
* Registered users of the site do not see these ads.
WRX03 is offline   Reply With Quote
Old 06-10-2010, 10:59 AM   #2
flightwatch
Scooby Specialist
 
Member#: 231058
Join Date: Nov 2009
Chapter/Region: South East
Location: St Petersburg, FL
Vehicle:
2013 Genesis Coupe
2.0T

Default

You could try resetting your ecu to start off with. Also, check that the tps is still good. Check the general condition of the tb to make sure it's in good working order.

It sounds like the ecu isn't opening the throttle plate enough to compensate for the extra engine load. Then when it does, it opens it too far, and it goes back and forth until it comes to a happy medium.
flightwatch is offline   Reply With Quote
Old 06-11-2010, 08:36 AM   #3
Boxer4Dad
Scooby Newbie
 
Member#: 137226
Join Date: Jan 2007
Chapter/Region: MWSOC
Location: SE Michigan
Vehicle:
2005 Saabaru 2.5i
OBP, or Black

Default

Also, check your throttle body. If there's gunk in there, the plate can get sticky. Cleaning it is cheap and fairly easy. I use the CRC Intake cleaner from my auto parts place, but use an intake cleaner and a rag to wipe up the goo.
Boxer4Dad is offline   Reply With Quote
Old 06-11-2010, 10:35 PM   #4
ronemus
Scooby Newbie
 
Member#: 124146
Join Date: Aug 2006
Chapter/Region: MWSOC
Vehicle:
'02 Legacy GT 5MT
Titanium

Default

A gummed up idle air control valve is another possibility; hit it with some carb cleaner when you do the throttle.
ronemus is offline   Reply With Quote
Old 06-12-2010, 02:53 PM   #5
WRX03
Scooby Specialist
 
Member#: 20744
Join Date: Jul 2002
Chapter/Region: MAIC
Location: Goodview, VA-SML
Vehicle:
05 Baja Regal Blue
03 WRX Little Red Wagon

Default

How about the front O2 sensor?

I cleaned the TB out before my wife took the Baja on a trip but it was a simple spraying the butterfly and the port leading up to the idle valve. After 500 miles it is still doing the same. She is still on her trip so I won't be able to really dig in to it But the "only when the air conditioner is on" is a little confusing. It doesn't following the compressor turning on/off.
WRX03 is offline   Reply With Quote
Old 06-27-2010, 06:00 AM   #6
WRX03
Scooby Specialist
 
Member#: 20744
Join Date: Jul 2002
Chapter/Region: MAIC
Location: Goodview, VA-SML
Vehicle:
05 Baja Regal Blue
03 WRX Little Red Wagon

Default

FYI. It was the IAT sensor, I take to mean Intake Air Temperature. It's the sensor mounted in the filter box. ~$65 online.
WRX03 is offline   Reply With Quote
Old 08-18-2010, 01:32 PM   #7
EVAN&MONICA
Scooby Newbie
 
Member#: 221802
Join Date: Aug 2009
Chapter/Region: NWIC
Location: Corbett OR
Vehicle:
2001 2.5RS coupe
BRP

Default

Quote:
Originally Posted by WRX03 View Post
FYI. It was the IAT sensor, I take to mean Intake Air Temperature. It's the sensor mounted in the filter box. ~$65 online.
Sweet ^ We've been dealing with this since we bought the RS (2.5NA) in feb, same exact problem, same exact conditions!

Happy to see you found the fix, I'll give it a try soon!
EVAN&MONICA 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
my Impreza's idle bounces! 04.STI Normally Aspirated Powertrain 7 02-07-2007 03:58 PM
04 STi idle bouncing. Vtecready Factory 2.5L Turbo Powertrain 15 09-16-2005 05:12 PM
problem with air conditioner please help boxer04 Factory 2.0L Turbo Powertrain 2 08-25-2005 10:51 AM
('93-'01) rally racing v. air conditioner condenser and radiator Damon Impreza Forum 4 06-01-2001 02:52 PM
help! Water from air conditioner? gumball Technical Forum Archive 6 09-05-2000 12:48 AM


All times are GMT -4. The time now is 07:31 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.