Welcome to the North American Subaru Impreza Owners Club Thursday April 18, 2019
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L 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.
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 02-28-2019, 01:25 PM   #51
Haive_Music
Scooby Newbie
 
Member#: 493578
Join Date: Nov 2018
Location: TN
Vehicle:
2017 STI
White

Default

Quote:
Originally Posted by Dwbarrett7 View Post
2017 STI with the same exact issue over 40ish degrees. All the bolt ons except for TGV deletes and upgraded turbo. Iíve been trying to resolve this issue since the fuel system was upgraded and ECU retuned. Since installation of AEM 320 fuel pump, id1300x injectors, Cobb stumble kit, and Cobb flex fuel kit the issue started. On 93 it only stumbles (surges) for 5 seconds and on E85 it lasts up to 90 seconds. Changed front 02 and deleted air pump thinking it could be the cause. This however did not resolve the issue. The shop that had performed the work and tuning has been more than willing to try to fix this issue but has had no luck. Iíll keep you posted if it ever gets solved. PS There is another thread about this too ď2016 STI SURGINGĒ
I find it very interesting that you're having this issue too, and that you don't have TGV deletes. Definitely seems more fueling related. You and I have very similar fueling setups, except I'm on 93 only - no flex fuel. I have the same pump, injectors, stumble fix kit, and also COBB's fuel rail and line kit.

I finally received a revised map yesterday from my tuner, 30+ days later. The good news is, the issue is lessened in severity, the bad new is - it's still there.


I didn't get too many details with the revision, but he basically said that he thinks that the car's o2 sensor isn't fully warmed up enough yet by the time it goes to switch into closed loop mode, and it mistakenly thinks the car is running in a rich condition, which it's not, and tries to compensate. He said that he has "adjusted the closed loop delay a bit for this revision to give the front o2 more time to warm up and to allow the post start enrichment table to run a bit longer before entering closed loop mode."


I've sent him another log, and am hopefully he can continue to work toward resolving this issue. I've seen similar posts from people with this issue lately too across other forums. Some people have learned to deal with the issue, others have had success with their tuners being able to resolve the issue. Really would be nice to get some more definitive answers to help lay this issue to bed once and for all.

I'll definitely post back with updates when/if I receive any.
* Registered users of the site do not see these ads.
Haive_Music is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 02-28-2019, 02:42 PM   #52
avikm289
Scooby Newbie
 
Member#: 315748
Join Date: Apr 2012
Chapter/Region: Tri-State
Location: Long island NY
Vehicle:
2017 wrx sti
ice silver metallic

Default

Quote:
Originally Posted by greygonzalez View Post
i have the same issue, i believe it has to do with the larger injectors. i'm running the same injectors you have tuned for e85 and from what i've been hearing depending on your tune the larger injectors start off rich and in order to compensate the car leans it self out to adjust (rpm dip) then since you're not moving it adds more fuel to prevent stalling and bumps up the rpm (hrnce the fluctuation). once its warmed up it goes away for the day. my tuner recommended tapping the gas to hold it at the higher idle when you first start it up and it goes away. this only happens on the first cold start of the day.
avikm289 is online now   Reply With Quote
Old 02-28-2019, 04:28 PM   #53
Dwbarrett7
Scooby Newbie
 
Member#: 421948
Join Date: May 2015
Location: Rhode Island
Vehicle:
2017 WRX STI
WR Blue Pearl

Default

Quote:
Originally Posted by avikm289 View Post
i have the same issue, i believe it has to do with the larger injectors. i'm running the same injectors you have tuned for e85 and from what i've been hearing depending on your tune the larger injectors start off rich and in order to compensate the car leans it self out to adjust (rpm dip) then since you're not moving it adds more fuel to prevent stalling and bumps up the rpm (hrnce the fluctuation). once its warmed up it goes away for the day. my tuner recommended tapping the gas to hold it at the higher idle when you first start it up and it goes away. this only happens on the first cold start of the day.
I think your tuner is right. This is basically what Iíve come up with too. Iíve read of Mustang owners having the same problems with these injectors. They ended up switching injectors and problem went away. Very costly experiment for me I rather just deal with it. People stand by injector dynamics very strongly but still makes me wonder. If you go through every post on this topic itís the only correlation :/.
Dwbarrett7 is offline   Reply With Quote
Old 02-28-2019, 11:38 PM   #54
Haive_Music
Scooby Newbie
 
Member#: 493578
Join Date: Nov 2018
Location: TN
Vehicle:
2017 STI
White

Default

Quote:
Originally Posted by Dwbarrett7 View Post
I think your tuner is right. This is basically what Iíve come up with too. Iíve read of Mustang owners having the same problems with these injectors. They ended up switching injectors and problem went away. Very costly experiment for me I rather just deal with it. People stand by injector dynamics very strongly but still makes me wonder. If you go through every post on this topic itís the only correlation :/.
Seems like an odd explanation to me, when you look at the wideband and it's sitting fine idling at 14.7 for 20 seconds and then *wham* leans out randomly for a few seconds, then everything's back fine.

However, that does seem to be a commonality here. I will say this is my second set of ID injectors across 2 cars, and while these idle better than my old ID1000's from back in the day, for me, nothing comes close to the idle/fuel control I had with my FIC 1100's. Never had a single problem with them. Wish I would have went with them on this built too.

Live and learn I suppose.
Haive_Music is offline   Reply With Quote
Old 03-01-2019, 02:56 AM   #55
Dwbarrett7
Scooby Newbie
 
Member#: 421948
Join Date: May 2015
Location: Rhode Island
Vehicle:
2017 WRX STI
WR Blue Pearl

Default

Quote:
Originally Posted by Haive_Music View Post
Seems like an odd explanation to me, when you look at the wideband and it's sitting fine idling at 14.7 for 20 seconds and then *wham* leans out randomly for a few seconds, then everything's back fine.

However, that does seem to be a commonality here. I will say this is my second set of ID injectors across 2 cars, and while these idle better than my old ID1000's from back in the day, for me, nothing comes close to the idle/fuel control I had with my FIC 1100's. Never had a single problem with them. Wish I would have went with them on this built too.

Live and learn I suppose.
The more I think about this too thereís one more thing that doesnít make sense. Seems like a large portion of the people say when the ambient temperature is cold it doesnít do it. For me it seems like that temperature is around 38-40ish degrees. 99% of the time under that temperature not even one hiccup. Just some more food for thought. Well, hopefully someone figures it out.
Dwbarrett7 is offline   Reply With Quote
Old 03-01-2019, 05:25 PM   #56
Haive_Music
Scooby Newbie
 
Member#: 493578
Join Date: Nov 2018
Location: TN
Vehicle:
2017 STI
White

Default

Quote:
Originally Posted by Dwbarrett7 View Post
The more I think about this too thereís one more thing that doesnít make sense. Seems like a large portion of the people say when the ambient temperature is cold it doesnít do it. For me it seems like that temperature is around 38-40ish degrees. 99% of the time under that temperature not even one hiccup. Just some more food for thought. Well, hopefully someone figures it out.
I'm afraid I can't offer much insight on that. I haven't taken ambient temperature into consideration, and I don't drive the car every day, but I can say that every single time I've started my car since I've done the mods/gotten tuned, it's done this, and there has been some fluctuation in the temps, although my car is kept in a (non-heated) garage.

It doesn't get super cold here, but I know there have been a few times I've started it up when it's colder, and still experienced the issue. Although I can't say for 100% certainty, I'm sure I've experienced this issue when I've had temperatures under 38-40 degrees.

I just looked at the 2 logs I've had, one of which shows coolant temp at about 733/74 degrees, the other right at 61 degrees. That's with the car sitting all night in the garage, but I wasn't monitoring ambient temp, so.... not sure.
Haive_Music is offline   Reply With Quote
Old 04-01-2019, 01:11 AM   #57
nasiocnerd
Scooby Newbie
 
Member#: 499216
Join Date: Mar 2019
Default

Same issue here. Since building my 15 STI with an IAG stage 2, 1.5 Dom, 1050x, Walbro 450, TGV and tuned at a highly reputable local shop, I have had the stumble on cold start. Just like in the previously posted videos. It's worse with lower temps, and today for the first time, I had the car stall out right after crank. Took a few starts to get it going and had to give it a good bit of throttle. My tuner did warn there might be a stumble in the 15+ STIs, but unknown why.

I'm wondering if there's a way to tune the cold start to idle at a higher RPM, aka prevent the stumbles?

Also, I'm already upgrading to 1300cc injectors, so hopefully it doesn't worsen the situation!

Will update if tuner has any solutions on the re-tune.
nasiocnerd is offline   Reply With Quote
Old 04-05-2019, 09:26 PM   #58
james-30
Scooby Newbie
 
Member#: 430450
Join Date: Sep 2015
Location: Indianapolis
Vehicle:
2019 STI
Lapis Blue

Default

2019 full bolt on sti doing the same thing. 431 whp on e85. My fuel pressure is shooting to 65-70 psi, 100% duty cycle for roughly 20-30 seconds. Once FP drops to normal engine smooths out and all is fine. FYI my rear o2 sensor has been completely removed.

93 octane log: https://docs.google.com/spreadsheets...#gid=972392134

E61 log: https://docs.google.com/spreadsheets...#gid=291028390

Mod list:
*factory long block
*Speed density pro tuned
*BCP x500+ turbo with oil lines
*Invidia catless downpipe
*P&L track series catback
*Grimmspeed top mount
*Grimmspeed up pipe with 40mm ts ewg
*Grimmspeed EBCS
*ID 1300cc injectors
*Factory Fuel rails, lines. Cobb fuel regulator
*High flow 340 lph pump
*DW hard wire kit
*COBB EBCS 1/4in EWG Fitting Kit
*Cobb intake
*Full Cobb e85 kit
*South Bend stage 3 clutch
*HKS ELH
*IAG street AOS
*Torque Solutions TGV
*Perrin Turbo Inlet Hose
*NGK Spark Plugs LFR7AIX
*Air pump block off kit


Last edited by james-30; 04-05-2019 at 09:39 PM.
james-30 is offline   Reply With Quote
Old 04-06-2019, 03:09 PM   #59
Haive_Music
Scooby Newbie
 
Member#: 493578
Join Date: Nov 2018
Location: TN
Vehicle:
2017 STI
White

Default

Quote:
Originally Posted by james-30 View Post
2019 full bolt on sti doing the same thing. 431 whp on e85. My fuel pressure is shooting to 65-70 psi, 100% duty cycle for roughly 20-30 seconds. Once FP drops to normal engine smooths out and all is fine. FYI my rear o2 sensor has been completely removed.

93 octane log: https://docs.google.com/spreadsheets...#gid=972392134

E61 log: https://docs.google.com/spreadsheets...#gid=291028390

Mod list:
*factory long block
*Speed density pro tuned
*BCP x500+ turbo with oil lines
*Invidia catless downpipe
*P&L track series catback
*Grimmspeed top mount
*Grimmspeed up pipe with 40mm ts ewg
*Grimmspeed EBCS
*ID 1300cc injectors
*Factory Fuel rails, lines. Cobb fuel regulator
*High flow 340 lph pump
*DW hard wire kit
*COBB EBCS 1/4in EWG Fitting Kit
*Cobb intake
*Full Cobb e85 kit
*South Bend stage 3 clutch
*HKS ELH
*IAG street AOS
*Torque Solutions TGV
*Perrin Turbo Inlet Hose
*NGK Spark Plugs LFR7AIX
*Air pump block off kit

2267B7C7 9A48 4BA1 9E35 CE8D457E6E3C - YouTube
Interesting, yours is more of a lope, and the issue isn't as severe as I've seen where the car damned near dies.

What I do find interesting, is the fuel pressure readings. I almost wonder if this is somehow related to the FPR? I have the same FPR setup, and the same pump.



An update to my issue - I spent a week at my tuners, and they were unable to resolve the issue. Supposedly, they were reaching out directly to COBB to see if they've encountered anything like this, and know of any fix, but I haven't heard anything back. Given that it was like pulling teeth to get them to even look at the car or respond to my initial inquiries for 2 months, I doubt I'll hear back.



In the interim - someone from this forum has reached out and thinks it's a tuning issue. They're working on a new map for me to try now. If they can successfully combat this issue, I'll def report back. *fingers crossed*. In either case, it's nice to finally find a tuner who seems to truly care and want to help. I think I'm done with the shop who tuned my car this last go around which is sad given their reputation.
Haive_Music is offline   Reply With Quote
Old 04-09-2019, 03:09 PM   #60
Haive_Music
Scooby Newbie
 
Member#: 493578
Join Date: Nov 2018
Location: TN
Vehicle:
2017 STI
White

Default

Odd question, especially given the new years / low milage vehicles that exhibit this problem, but has anyone attempted trying to install a brand new front O2 sensor by chance?

I've been tempted to try it, but considering the car only has 12k miles on it, I doubt it went bad already, but...the problem does seem to happen right when the sensor begins reading.
Haive_Music is offline   Reply With Quote
Old 04-10-2019, 08:10 PM   #61
nasiocnerd
Scooby Newbie
 
Member#: 499216
Join Date: Mar 2019
Default

I retuned my 15sti after installing ID 1300x injectors, this time with a different tuner. I did find out that my fuel pump was still stock even though I paid for a walbro 450, and also replaced that.

He states he has not had any stumble issues with any customer cars, and it all has to do with the fuel trims. He did spend a good bit of time setting everything up. I have not had any issues since then, even on a little colder days.

So ultimately, it sounds like it may all just be in the tune after all.
nasiocnerd is offline   Reply With Quote
Old 04-11-2019, 09:07 PM   #62
james-30
Scooby Newbie
 
Member#: 430450
Join Date: Sep 2015
Location: Indianapolis
Vehicle:
2019 STI
Lapis Blue

Default

Quote:
Originally Posted by nasiocnerd View Post
I retuned my 15sti after installing ID 1300x injectors, this time with a different tuner. I did find out that my fuel pump was still stock even though I paid for a walbro 450, and also replaced that.

He states he has not had any stumble issues with any customer cars, and it all has to do with the fuel trims. He did spend a good bit of time setting everything up. I have not had any issues since then, even on a little colder days.

So ultimately, it sounds like it may all just be in the tune after all.
Who is your tuner?
james-30 is offline   Reply With Quote
Old 04-14-2019, 11:38 AM   #63
nasiocnerd
Scooby Newbie
 
Member#: 499216
Join Date: Mar 2019
Default

Doug at DBW Motorsport
nasiocnerd is offline   Reply With Quote
Old 04-14-2019, 02:35 PM   #64
james-30
Scooby Newbie
 
Member#: 430450
Join Date: Sep 2015
Location: Indianapolis
Vehicle:
2019 STI
Lapis Blue

Default

Quote:
Originally Posted by nasiocnerd View Post
Doug at DBW Motorsport
Doug have a facebook account so I can message him direct?
james-30 is offline   Reply With Quote
Old 04-14-2019, 04:02 PM   #65
Haive_Music
Scooby Newbie
 
Member#: 493578
Join Date: Nov 2018
Location: TN
Vehicle:
2017 STI
White

Default

Quote:
Originally Posted by nasiocnerd View Post
Doug at DBW Motorsport
Damn, they're like 20 mins away from where I just was at with my tuner - who was unable to resolve the issue! If I would have known that, I would have just scheduled something up with him instead.

I'm pretty sure I'm going to just have to bite the bullet and find another tuner. I guess the question now is if I get ahold of your guy, or if I try contacting Boxer4Racing which I've also heard good things about. I won't be going back to Top Speed again....
Haive_Music is offline   Reply With Quote
Old 04-14-2019, 04:06 PM   #66
nasiocnerd
Scooby Newbie
 
Member#: 499216
Join Date: Mar 2019
Default

Quote:
Originally Posted by james-30 View Post
Doug have a facebook account so I can message him direct?


There should be a Facebook page for DBW Motorsport if you look it up.
nasiocnerd is offline   Reply With Quote
Old 04-14-2019, 04:10 PM   #67
nasiocnerd
Scooby Newbie
 
Member#: 499216
Join Date: Mar 2019
Default

Quote:
Originally Posted by Haive_Music View Post
Damn, they're like 20 mins away from where I just was at with my tuner - who was unable to resolve the issue! If I would have known that, I would have just scheduled something up with him instead.



I'm pretty sure I'm going to just have to bite the bullet and find another tuner. I guess the question now is if I get ahold of your guy, or if I try contacting Boxer4Racing which I've also heard good things about. I won't be going back to Top Speed again....


Iím not trying to advertise or anything, but my tune from Doug was so much better than my previous one from another reputable tuner. You will not be disappointed. I also wished I would have known of DBW sooner. Btw, Doug actually started Topspeed back in the day.
nasiocnerd is offline   Reply With Quote
Old 04-14-2019, 05:07 PM   #68
james-30
Scooby Newbie
 
Member#: 430450
Join Date: Sep 2015
Location: Indianapolis
Vehicle:
2019 STI
Lapis Blue

Default

Quote:
Originally Posted by nasiocnerd View Post
Iím not trying to advertise or anything, but my tune from Doug was so much better than my previous one from another reputable tuner. You will not be disappointed. I also wished I would have known of DBW sooner. Btw, Doug actually started Topspeed back in the day.
Yea, I found their page before I asked abt contacting Doug direct. No big, Iíll reach out and see what they say. I live in Indiana but if they can retune my car to not have this annoying stumble then Iíll ship my car first thing Monday morning. In my opinion this stumble is unacceptable! My build cost me 12k and Iíd be damned if Iím just going to accept and forget abt this issue.
james-30 is offline   Reply With Quote
Old 04-14-2019, 07:40 PM   #69
nasiocnerd
Scooby Newbie
 
Member#: 499216
Join Date: Mar 2019
Default

Quote:
Originally Posted by james-30 View Post
Yea, I found their page before I asked abt contacting Doug direct. No big, Iíll reach out and see what they say. I live in Indiana but if they can retune my car to not have this annoying stumble then Iíll ship my car first thing Monday morning. In my opinion this stumble is unacceptable! My build cost me 12k and Iíd be damned if Iím just going to accept and forget abt this issue.


If you call their number, you can usually talk directly with him. Good luck! Let us know how it turns out.
nasiocnerd 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 06:16 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2019 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.