Welcome to the North American Subaru Impreza Owners Club Thursday December 25, 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 > Engine Management & Tuning > AccessPort

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 03-08-2013, 11:23 PM   #1
matts
Scooby Newbie
 
Member#: 322939
Join Date: Jun 2012
Location: midwest
Vehicle:
10 WRX
96 LSi

Default Fuel pump duty cycle

When I start the car up the fuel pump runs at 100% dc for like the first minute. The ecu is trying like hell to correct AFR (-20% to -25%)at this totally unnecessary flow rate. When it goes back to 33% dc all is well. Does this huge negative compensation mean my fpr is bad or going bad? I guess I don't see the point of running the pump so high during idle. Is this maxed out condition at startup normal? Should I be concerned?
* Registered users of the site do not see these ads.
matts is offline   Reply With Quote
Old 03-11-2013, 11:44 AM   #2
Cobb Tuning
NASIOC Vendor
 
Member#: 4803
Join Date: Mar 2001
Location: Austin, DFW, Portland, SOCAL
Default

Quote:
Originally Posted by matts View Post
When I start the car up the fuel pump runs at 100% dc for like the first minute. The ecu is trying like hell to correct AFR (-20% to -25%)at this totally unnecessary flow rate. When it goes back to 33% dc all is well. Does this huge negative compensation mean my fpr is bad or going bad? I guess I don't see the point of running the pump so high during idle. Is this maxed out condition at startup normal? Should I be concerned?
Fuel pump duty at 100% after engine start for a short period of time is the expected behavior and part of the ECU code. As far as why you are seeing large corrections, we would need to know what car this is, your mods, what map you are running. That said, you can see some unusual corrections briefly after cold start or during warm-up enrichment even on a stock car. I would try to get a data log and post it up so we can take a look at it.

Bill
Cobb Tuning is offline   Reply With Quote
Old 03-11-2013, 11:55 AM   #3
matts
Scooby Newbie
 
Member#: 322939
Join Date: Jun 2012
Location: midwest
Vehicle:
10 WRX
96 LSi

Default

The corrections taper off to +/- 1% to 3% after the duty cycle switches to 33%.

10' WRX. I have a walbro 255 and use the stock regulator setup. My map is the one editted from your ots stg2. I didn't edit anything in regard to the fuel pump.

I was just concerned about the stock regulator. If this behavior is the norm, then I will not worry about it.

Last edited by matts; 03-11-2013 at 12:03 PM. Reason: redundant comments removed
matts 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 09:10 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.