Welcome to the North American Subaru Impreza Owners Club Thursday March 28, 2024
Home Forums Images 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.







* 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 07-10-2018, 11:34 AM   #1
NoTorq
Scooby Newbie
 
Member#: 456717
Join Date: Oct 2016
Location: MA
Vehicle:
15 Sti
DGM

Default CEL's got me all over the place

So the car is a 15 wrx sti with 70k miles.
Mods- ELH and Catless DP with Protune.

Issue- Misfiring and strong hesistation when under heavy load.
CEL's- P0302, P0352

What i have replaced so far using all OEM Subaru parts-
Replaced all 4 coils-
Replaced all 4 spark plugs
Replaced purge valve
Cleaned the MAF sensor
Added Techron Fuel injector cleaner

What im replacing next is the fuel pump with an AEM one.


Im at a loss, all i can think of next is maybe an injector in cyl 2?
* Registered users of the site do not see these ads.
NoTorq is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 07-11-2018, 08:13 AM   #2
alexholl
Scooby Newbie
 
Member#: 458056
Join Date: Nov 2016
Chapter/Region: NESIC
Location: NY/CT
Vehicle:
2005 FXT Premium
Obsidian Black Pearl

Default

Before you start throwing parts at it and waisting money, Understand that a P0352 and P0302 is an ignition coil system malfunction and a cylinder 2 misfire. Your misfire is very likely caused by a short/break in the cylinder 2 coil pack wire or an issue with the computer that controls the ignition since you have new coil packs and spark plugs. Other experts will know more than I do about the electronic components.

Just for future reference, Its easier and cheaper to swap expensive parts like coil packs and injectors from other working cylinders to see if the issue moves with the part, rather than replacing all of them right away. Ask me how I know
alexholl is offline   Reply With Quote
Old 07-11-2018, 02:25 PM   #3
mrsaturn7085
Scooby Specialist
 
Member#: 375462
Join Date: Dec 2013
Chapter/Region: NWIC
Location: Portland, OR
Vehicle:
2006 Impreza WRX STI
WR Blue

Default

How much boost are you tuned to, and how 'pro' is your 'protune' (i.e. who did the tune...)?

You've addressed a possible bad coil/plug on the no.2 cylinder so there are two possibilities - bad ECU pin/wiring (uncommon but it happens... I personally had an injector wire back out of an OEM harness plug last year) or unsafe tune (noted that you only experience this under heavy load).

Wiggle the under-hood harnesses while the engine is running and see if you can cause the engine to misfire. Also, check your spark gap. Read your plugs if you can... but if you can't, I understand - unfortunately this requires killing the engine under load for your condition and pushing the car into the garage since the plugs aren't easy to access. If you do this, do NOT forget that you'll lose power brakes when you cut the motor while you're flooring it.

For the unsafe tune idea, you can post your tune or a few logs (research which data-points to log, it is explained all over the forum). Chances are, the tune is locked and you won't be able to see it.

You don't have a bad injector - you would get an injector open/short CEL if you did.
mrsaturn7085 is offline   Reply With Quote
Old 07-11-2018, 03:06 PM   #4
NoTorq
Scooby Newbie
 
Member#: 456717
Join Date: Oct 2016
Location: MA
Vehicle:
15 Sti
DGM

Default

Yea spent a good amount on coils and plugs already but i figured what the hell, im a bit anal about maint. so i did them all anyways.


Protuned by Brentuning. But i have been tuned by them since december and have had 0 issues till now. I dont blame their tune whatsoever. As far as moving the harness around while car is running so see if anything happens, i did that aswell and nothing so far.

As i have ran thru more of my fuel with the injector cleaner added in, the CEL has gone away but their is LESS misfire's but if i attempt to go WOT it will start misfiring. It definitley is smoother driving around the city as i had misfires even pulling out of a driveway before injector cleaner.

This is the reason im thinking it's the injector. Tomorrow i will install a new oem one on cyl 2 and hope for the best
NoTorq is offline   Reply With Quote
Old 07-11-2018, 07:08 PM   #5
mrsaturn7085
Scooby Specialist
 
Member#: 375462
Join Date: Dec 2013
Chapter/Region: NWIC
Location: Portland, OR
Vehicle:
2006 Impreza WRX STI
WR Blue

Default

Worth a shot, if the injector is lazy without being fully open/closed electrically, it may not throw it's specific code.
mrsaturn7085 is offline   Reply With Quote
Old 07-13-2018, 02:16 PM   #6
NoTorq
Scooby Newbie
 
Member#: 456717
Join Date: Oct 2016
Location: MA
Vehicle:
15 Sti
DGM

Default

Replaced injector.

Cleared CEL

Went for a test run

Boom P0352 is back :|

fml
NoTorq is offline   Reply With Quote
Old 07-15-2018, 10:07 AM   #7
Elbert Bass
Scooby Specialist
 
Member#: 283429
Join Date: May 2011
Chapter/Region: South East
Location: Down yonder.
Vehicle:
2016 Fuji Sunfire 03
Silver

Default

OK, I see you going in circles. As noted that P0352 indicates a fault in the coil drive circuit so it won't be an injector issue (as already noted). Lets try using a diagnostic procedure other than swapping parts - that is so 1970's...

You need to perform the electrical tests on the wires between the ECM and #2 coil pack. Short to each other, short to power, short to ground, high resistance end to end, poor connections at each end.

If you have an oscilloscope tap into the trigger wire at the coil and watch the pattern from the ECM during misfire - should be a nice evenly timed square wave signal that gets closer together with faster RPM.

Given that you have a new coil/swapped coils if wiring checks out but the "primary" pattern drops out it could be the coil driver in the ECM.
Elbert Bass is offline   Reply With Quote
Old 07-15-2018, 02:33 PM   #8
mrsaturn7085
Scooby Specialist
 
Member#: 375462
Join Date: Dec 2013
Chapter/Region: NWIC
Location: Portland, OR
Vehicle:
2006 Impreza WRX STI
WR Blue

Default

NoTorq - fill out your profile, once in a while you'll find someone local to help.
mrsaturn7085 is offline   Reply With Quote
Old 07-16-2018, 08:48 AM   #9
NoTorq
Scooby Newbie
 
Member#: 456717
Join Date: Oct 2016
Location: MA
Vehicle:
15 Sti
DGM

Default

So i changed the fuel pump to an AEM one.
Still have an issue.

No longer seem to be getting P0302

Car has it moments where it can full wot
Then has moments where it hesitates/misfires? under WOT and somethings even minor ones when in low rpm and pops up with P0352.

Elbert, i didnt mind changing the coil and plugs since i want the motor to be as healthy as can be.

Injector i just bought one just incase it was causing the the P0302 code.

And fuel pump i upgraded to future proof.

But i agree on the wiring issue since it looks like that is what its probably gonna be.

I hate wiring issues :|
NoTorq is offline   Reply With Quote
Old 08-11-2018, 10:02 AM   #10
NoTorq
Scooby Newbie
 
Member#: 456717
Join Date: Oct 2016
Location: MA
Vehicle:
15 Sti
DGM

Default

Just to update for anyone having similar issues in the future
Well it's been over a month now. Finally solved it.

I took it to Brentuning for a steering rack replacement (oem one started leaking)
While doing that service they peeked into my existing issue.

They couldn't narrow it down. They installed a Cobb FPR kit. Then dyno put it on the dyno and did some pulls. Car had 0 issues when on the dyno. But once you took it on the street then it would continously hesistate. I was recommended to remove my Compustar Alarm just incase that was the issue.

So i removed the alarm. Still had the CEL.

With no luck anywhere and Subaru not wanting to give me a wiring diagram, as i searched online a member on IWSTI named Wade-0 pm'd the diagrams i was looking for.

Put the car on the lift. Started looking at the harness. And finally found it. The harness coming off the firewall was orignally ziptied when the DP was installed almost a year ago and somehow broke,
So some wires were touching the COBB heatshield and the rubber melted off exposing the wire to the meal shield.

Ziptied it back and BOOM issue solved
NoTorq is offline   Reply With Quote
Old 08-20-2018, 11:45 AM   #11
NoTorq
Scooby Newbie
 
Member#: 456717
Join Date: Oct 2016
Location: MA
Vehicle:
15 Sti
DGM

Default

So car ran fine for a week after i zip tied the harness away from the heatshield. Had not had time to repair the wiring.

Midweek there was a big rain storm. Had to go thru a good small puddle of water. CEL popped up for P0352. Next day hot and dry the CEL went away. Im going to assume water hit the exposed wires causing the CEL to pop up.

Fast forward 2 days later. Drove the car and parked it at a store. It was driving perfectly until i parked it. It no longer starts. Towed it and cut the exposed wires and spliced it with new same size wire.

So the wiring issue is fixed on the end of being exposed and barely connected.

Now the car still wont start. Only cranks and cranks. One thing after another.
NoTorq is offline   Reply With Quote
Old 09-05-2018, 10:21 AM   #12
NoTorq
Scooby Newbie
 
Member#: 456717
Join Date: Oct 2016
Location: MA
Vehicle:
15 Sti
DGM

Default

So to update and help anyone in the future reading this.

I towed the car to Wicked Performance Group in Manchester,NH over labor day weekend.

Explained to them my ongoing issues with the car. They said np and they will get it taken care of.

Tuesday after labor day, i can get an email from Wicked Performance stating car is good to go.

Cleaned up the wiring mess that was left over from the splicing and while checking my fuel pump found a o-ring missing on the supply line. They put a new one and bam. Cars running like a champ.
0 Cel's
Glorious WOT pulls.

Life is great again.

Big thanks to Tom and Jay from Wicked Performance
NoTorq 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 12:36 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.