Welcome to the North American Subaru Impreza Owners Club Sunday December 17, 2017
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
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. 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 08-08-2005, 02:02 PM   #1
Scooby Specialist
Member#: 2604
Join Date: Oct 2000
Chapter/Region: NESIC
Location: CA
1999 2.5RSt

Default RS ECU wow - Knock Correction

So I was pretty sure that my shortblock was blown for about a week. I had just installed my Emanage Ultimate and the car was running extremely slugish and with almost no power. I had the boost way down till I had time to do some significant retuning and was hoping that it was just my learning curve and the new nature of the ultimate that was causing my issues.

Well I decided to log the stock ECU to see if everything was happy sensor wise and came accross an interesting MIL code "Knock Sensor Circuit Malfunction".

I had never seen that code but decided to check it out and swapped out the knock sensor... no luck

Looking at the dataloggs closer revealed that the ECU was droping to 4 degrees of advance at partial throttle!!!! 4! and holding at 4 seemingly indefinitely! If that is what limp mode entails thats pretty extreme!! I am pretty sure I wasn't in limp mode cause I could rev past 4k If I really tried. The car made absolutely no power at all with good reason!

SO I found that the Ultimate was pulling the knock sensor up! I haven't got the knock detection on the ultimate running yet but wired it regardless to see if it would work. So basically it was causing the stock ECU to see intense knock ALL the time.

After fixing the pull up issue the car now runs as smooth as ever again. Looks like I'll go back to using the J&S for knock detection till I find a better solution / get the ultimate detection compairible.

So the moral of the story is the Stock ECU is incredible in its capacity to remove timing with respect to knock. I see almost 40 degrees sometimes on light throttle and for it to drop it to 4! Thats pretty extreme!

On the other hand its good to know that the stock ecu has the capibility to trim ignition to that degree. I suggest everyone RSt buy a cable from http://tactrix.com/ and get the free ECU logger from http://www.tari.co.za/ and check out the iGN timing and knock correction that your ECU is currently running while turbo - send me the logs too just out of curiosity - [email protected]
Hitokiri is offline   Reply With Quote

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
How come I Can't see feedback knock correction, fine learning knock correction? AraSh Open Source Reflashes 23 01-08-2014 08:04 PM
fbkc, knock sum, knock correction advance, help kh15 Open Source Reflashes 7 06-05-2009 01:56 PM
Correlations between Knock Lite and negative knock correction xFactor Engine Management & Tuning 1 01-12-2006 08:36 PM
ECU reset-> 16 IAM = "aggressive" knock correction BIGSKYWRX Engine Management & Tuning 13 05-10-2005 11:18 AM
Knock Correction and timing (long!) Ryan23 Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 14 06-28-2002 08:18 PM

All times are GMT -4. The time now is 01:50 AM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2017 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.