Welcome to the North American Subaru Impreza Owners Club Saturday November 16, 2019
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)

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.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 10-02-2019, 01:39 AM   #1
mik_sti
Scooby Newbie
 
Member#: 470125
Join Date: Jun 2017
Vehicle:
2005 Impreza
Candy Blue

Default Insanely high injector duty cycle HELP!!!

Hey subaru folks, looking for some technical advice. Ive been seeing some crazy high injector duty cycles lately for eg while revving under no load at 5-6k rpm ill see figues of about 150%. Sometimes i would also get a really lean break up and hesitation whilst driving also, lean as in off my wide band lean and wont cross 2k rpm, but doesnt happen all the time. I only started to notice this problem after i installed a 10 gallon fuel cell with a gravity fed 044 pump that is hardwired. But im not entirely sure what could be the problem, i suspect the pump may be trash or i may have a wiring issue on the engine harness side. But im not sure, the fuel pressure reg seems to be working and i cleaned my injectors recently too. Any thoughts?
Mods:
044 300lph pump hardwired (10an gravity fed, 6an to engine)
10 gal fuel cell
Rc750cc injectors
Tomei fuel pressure reg type s with rails in parallel
Tomei M7960 turbo
Tial 38mm Ewg with 14psi spring
* Registered users of the site do not see these ads.
mik_sti is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 10-02-2019, 02:51 AM   #2
mik_sti
Scooby Newbie
 
Member#: 470125
Join Date: Jun 2017
Vehicle:
2005 Impreza
Candy Blue

Default


Ignore my afr correction, only reason it’s so high I because I turned up the base pressure a little to see if it would lower the injector duty
mik_sti is offline   Reply With Quote
Old 10-02-2019, 08:23 AM   #3
rtv900
Scooby Guru
 
Member#: 428511
Join Date: Aug 2015
Location: philadelphia
Vehicle:
2016 STI

Default

Quote:
Originally Posted by mik_sti View Post
ill see figues of about 150%.
You must be in a time vortex or something if you injector is operating 50% more time than exists

either that or the data is simply incorrect
rtv900 is offline   Reply With Quote
Old 10-02-2019, 12:01 PM   #4
mik_sti
Scooby Newbie
 
Member#: 470125
Join Date: Jun 2017
Vehicle:
2005 Impreza
Candy Blue

Default

Quote:
Originally Posted by rtv900 View Post
You must be in a time vortex or something if you injector is operating 50% more time than exists

either that or the data is simply incorrect
���������� I really hope I’m not in a time vortex. I’m certainly not the tuner, but I could post the injector data on the map, if you want ?

Last edited by mik_sti; 10-02-2019 at 01:09 PM.
mik_sti is offline   Reply With Quote
Old 10-02-2019, 01:08 PM   #5
rtv900
Scooby Guru
 
Member#: 428511
Join Date: Aug 2015
Location: philadelphia
Vehicle:
2016 STI

Default

^all I mean is a 100% duty cycle means that the injector is 'open' (spraying) 100% of the time.
So it can't really be spraying fuel 150% of the time right? If that were the case it would be spraying fuel 3 seconds out of every 2 seconds of real time, hence the time vortex comment.

Something is borked with your data
rtv900 is offline   Reply With Quote
Old 10-02-2019, 01:10 PM   #6
mik_sti
Scooby Newbie
 
Member#: 470125
Join Date: Jun 2017
Vehicle:
2005 Impreza
Candy Blue

Default

Quote:
Originally Posted by rtv900 View Post
^all I mean is a 100% duty cycle means that the injector is 'open' (spraying) 100% of the time.
So it can't really be spraying fuel 150% of the time right? If that were the case it would be spraying fuel 3 seconds out of every 2 seconds of real time, hence the time vortex comment.

Something is borked with your data
what youre saying makes sense, I appreciate that you took the time to reply.
This is the injector data ive got

Here is the manufacturer data https://www.rcfuelinjection.com/Port...tency_Time.pdf

dead times on my map:
6.5V= 3.20ms
9.0V=1.13ms
11.5V=0.80ms
14.0v=0.62ms
16.5v=0.46ms

flow rate = 750.09cc
mik_sti is offline   Reply With Quote
Old 10-02-2019, 01:32 PM   #7
subaru_gc8
Scooby Specialist
 
Member#: 29292
Join Date: Nov 2002
Chapter/Region: SCIC
Location: Orange County CA
Vehicle:
2004 WRX wagon
silver

Default

Quote:
Originally Posted by mik_sti View Post
what youre saying makes sense, I appreciate that you took the time to reply.
This is the injector data ive got

Here is the manufacturer data https://www.rcfuelinjection.com/Port...tency_Time.pdf

dead times on my map:
6.5V= 3.20ms
9.0V=1.13ms
11.5V=0.80ms
14.0v=0.62ms
16.5v=0.46ms

flow rate = 750.09cc
something isnt right on your data. I would point to the latency or scaling as being off, just fyi the numbers they injector copanies give arent always right.. I had to adjust mine for my ID's to make the car run

Last edited by subaru_gc8; 10-05-2019 at 01:33 AM.
subaru_gc8 is offline   Reply With Quote
Old 10-11-2019, 09:31 AM   #8
subaruandmr2
Scooby Newbie
 
Member#: 472573
Join Date: Aug 2017
Vehicle:
2003 Impreza WRX
WRB

Default

IDC can go well past 100% as seen before with others logging and pushing the stock injectors (although 150% is a bit high). So the issue could be with your logging but if you're experiencing lean conditions on your wideband then thats indicitive of your fuel pump failing.
If your fuel pump can't maintain proper pressure, the injectors would need to stay open much longer to get the same amount of fuel in. This is why increasing your fuel pressure is equivalent to increasing injector size.

Go borrow a fuel pressure test kit from Autozone. The loan them out for free, although they will put a $150 charge on a credit card that you get back when you return the kit. With the kit you can check your fuel pressure at idle. It should be roughly 43.5 psi. I suspect you're going to see like 10psi of pressure when you go to check.
subaruandmr2 is offline   Reply With Quote
Old 10-16-2019, 12:30 AM   #9
mik_sti
Scooby Newbie
 
Member#: 470125
Join Date: Jun 2017
Vehicle:
2005 Impreza
Candy Blue

Default

Quote:
Originally Posted by subaruandmr2 View Post
IDC can go well past 100% as seen before with others logging and pushing the stock injectors (although 150% is a bit high). So the issue could be with your logging but if you're experiencing lean conditions on your wideband then thats indicitive of your fuel pump failing.
If your fuel pump can't maintain proper pressure, the injectors would need to stay open much longer to get the same amount of fuel in. This is why increasing your fuel pressure is equivalent to increasing injector size.

Go borrow a fuel pressure test kit from Autozone. The loan them out for free, although they will put a $150 charge on a credit card that you get back when you return the kit. With the kit you can check your fuel pressure at idle. It should be roughly 43.5 psi. I suspect you're going to see like 10psi of pressure when you go to check.
i really appreciate your feedback, im currently setting up a new fuel pump, seems i was experiencing premature pump failure due to the foam in the fuel cell breaking down and getting trapped in the pump.
mik_sti is offline   Reply With Quote
Old 10-16-2019, 10:21 AM   #10
rtv900
Scooby Guru
 
Member#: 428511
Join Date: Aug 2015
Location: philadelphia
Vehicle:
2016 STI

Default

Quote:
Originally Posted by subaruandmr2 View Post
IDC can go well past 100%
ok, then the figure is not actually duty cycle, it is another factor of some kind and they're just using the term duty cycle

duty cycle is run time out of actual time
nothing can run more than 100% of the time
rtv900 is offline   Reply With Quote
Old 10-17-2019, 01:13 AM   #11
mrsaturn7085
Scooby Specialist
 
Member#: 375462
Join Date: Dec 2013
Chapter/Region: NWIC
Location: Portland, OR
Vehicle:
2006 Impreza WRX STI
WR Blue

Default

The logger lists injector duty, but the readings and the way he revved it correspond with MAP in kPa units.

Check your data channels in the display.
mrsaturn7085 is offline   Reply With Quote
Old 10-31-2019, 11:30 PM   #12
mik_sti
Scooby Newbie
 
Member#: 470125
Join Date: Jun 2017
Vehicle:
2005 Impreza
Candy Blue

Default

Quote:
Originally Posted by mrsaturn7085 View Post
The logger lists injector duty, but the readings and the way he revved it correspond with MAP in kPa units.

Check your data channels in the display.
i borrowed the laptop i was using and was in a mild rush, i installed a fresh new aem pump and redid the wiring, and have been logging different parameters for the past few days, however my injector duty is still pretty high like 102%. I should mention that my maf scaling wasnt completed when tuning due to the high idc, so i dont know if that is contributing to the issue. Im gonna try throwing in another fpr, try some wrx decaps and check my engine harness later in the week.
mik_sti 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 05:14 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2019 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.