Welcome to the North American Subaru Impreza Owners Club Thursday July 10, 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 01-10-2013, 10:39 PM   #1
Pickler
Scooby Newbie
 
Member#: 301247
Join Date: Nov 2011
Location: Toronto
Vehicle:
09 Impreza 2.5i MT
White

Default help ignition timing problem

my maximum ignition timing during cruising at 2500rpm keeps changing some days. i can hit 35-38 deg max on one day and 42-45 the other. With the higher ignition timing i get much better fuel economy. Most of the time though my car is in 35-38 deg range. i'm wondering whats causing this drop in timing? i also found that if i restart the car after its fully warm it tends to advance the ignition timing? wtf? anyone has any clue?

09 impreza 2.5i sedan premium 4eat stock 40k miles on the odo. changed plugs at 30k miles with laser platinums.
* Registered users of the site do not see these ads.
Pickler is offline   Reply With Quote
Old 01-11-2013, 12:58 AM   #2
RaceFaceXC
NASIOC Supporter
 
Member#: 165749
Join Date: Dec 2007
Chapter/Region: South East
Location: stupid Florida
Vehicle:
2007 No YELLING
on the bus!

Default

Fuel quality/octane or OAT are the most relevant reasons for ignition timing to change, load, rpm and mixture being the same.
RaceFaceXC is offline   Reply With Quote
Old 01-11-2013, 05:02 PM   #3
Pickler
Scooby Newbie
 
Member#: 301247
Join Date: Nov 2011
Location: Toronto
Vehicle:
09 Impreza 2.5i MT
White

Default

i have been suspecting fuel. i have always used e10 87 octane gas. today on the way home i was averaging 42 degrees whilst yesterday only 35 degrees same route.

i forgot to add that once i noticed ign fall to -1 during cruising and back to 35. happend fairly quickly.
Pickler is offline   Reply With Quote
Old 01-11-2013, 07:34 PM   #4
RaceFaceXC
NASIOC Supporter
 
Member#: 165749
Join Date: Dec 2007
Chapter/Region: South East
Location: stupid Florida
Vehicle:
2007 No YELLING
on the bus!

Default

I know the knock correction logic pretty well but not necessarily the ecu decides what timing table to use for cruise. Pull a learning view screen shot and pull your timing tables also. See if there is knock in the range of cruise where the changes are occurring or maybe you are just in between two cells interpolating and it switches back and forth. Seems like a large change in timing for one cell over on the table, though.

Also, this might be discussed better in the engine management forum.
RaceFaceXC is offline   Reply With Quote
Old 01-11-2013, 09:16 PM   #5
Pickler
Scooby Newbie
 
Member#: 301247
Join Date: Nov 2011
Location: Toronto
Vehicle:
09 Impreza 2.5i MT
White

Default

ok thanks for the help
Pickler 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 02:27 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.