Welcome to the North American Subaru Impreza Owners Club Monday September 23, 2019
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Normally Aspirated 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.







* 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 08-01-2019, 06:44 PM   #1
pcampbell
Scooby Newbie
 
Member#: 437670
Join Date: Jan 2016
Location: VT
Vehicle:
2005 2.5 SC OB

Default Cyl 1 misfire - changed plugs ,wires, coil

I have a supercharged ej253 which misfires on cyl 1 only above 5500rpm and 10psi (this is a WOT pull). I have swapped plugs with cyl 2 (no change), wire on cyl 1 (no change) and coil (no change).

Any ideas on what to try next? Compression is good, have not done leak down. Have also not tried swapping injectors left/right, etc.

It does not misfire at light load/high rpm.

WOT PULL LOG here. It's running a bit rich right now but the misfires were happening earlier.
https://drive.google.com/open?id=0By...JzNndnMnlVY0pJ
* Registered users of the site do not see these ads.

Last edited by pcampbell; 08-01-2019 at 07:08 PM.
pcampbell is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 08-02-2019, 01:15 PM   #2
pcampbell
Scooby Newbie
 
Member#: 437670
Join Date: Jan 2016
Location: VT
Vehicle:
2005 2.5 SC OB

Default

Gapping tighter seems to make the problem occur at higher RPM and higher boost level which makes me hopefully that going even tighter will make it go away. But I don't understand why it is cyl 1 only.
pcampbell is offline   Reply With Quote
Old 08-02-2019, 06:03 PM   #3
pcampbell
Scooby Newbie
 
Member#: 437670
Join Date: Jan 2016
Location: VT
Vehicle:
2005 2.5 SC OB

Default

Ok nevermind the plug gap isn't fixing it. I am back to being confused. Going to try swapping injectors next.

I need help with this but I think the fact that it only happens > 5500rpm and 10+psi is an indicator of something, I just don't know what exactly.

Last edited by pcampbell; 08-02-2019 at 06:34 PM.
pcampbell is offline   Reply With Quote
Old 08-02-2019, 08:04 PM   #4
pcampbell
Scooby Newbie
 
Member#: 437670
Join Date: Jan 2016
Location: VT
Vehicle:
2005 2.5 SC OB

Default

I added 1 new ground strap today and ordered 3 more to install next week. I will try swapping #1 and #3 injectors.
pcampbell is offline   Reply With Quote
Old 08-08-2019, 03:00 PM   #5
pcampbell
Scooby Newbie
 
Member#: 437670
Join Date: Jan 2016
Location: VT
Vehicle:
2005 2.5 SC OB

Default

Still no luck...
pcampbell is offline   Reply With Quote
Old 08-08-2019, 06:00 PM   #6
yarrgh
Scooby Specialist
 
Member#: 80465
Join Date: Jan 2005
Chapter/Region: RMIC
Location: Denver
Vehicle:
2001 2.5RS
Black Diamond Pearl

Default

What's the compression and leak down numbers on all cyls? How's the valve lash?
yarrgh is offline   Reply With Quote
Old 08-09-2019, 07:42 AM   #7
pcampbell
Scooby Newbie
 
Member#: 437670
Join Date: Jan 2016
Location: VT
Vehicle:
2005 2.5 SC OB

Default Cyl 1 misfire - changed plugs ,wires, coil

Thanks. Compression was (cold):

1,3,2,4: 187,190,200,195


Leakdown on 1 was very low like 2% but Iíll check again on other cylinders.

These are not very high quality gauges so I am sure these some room for error in the compression numbers but the idea is there.

I have not checked valve lash adjustment yet although the heads and were done 15k miles ago, hopefully done correctly then but you never know. Do you think that would cause a high rpm high load misfire ? Thereís a decent amount of room to remove valve cover when I remove the SC so maybe that is next.

I should note that itís not strictly at 5500 plus. I might be at 5000rpm but only under WOT. At lighter throttle / load itís fine.

Last edited by pcampbell; 08-09-2019 at 07:57 AM.
pcampbell is offline   Reply With Quote
Old 08-10-2019, 02:07 AM   #8
CosmoTheCat
Scooby Newbie
 
Member#: 3409
Join Date: Jan 2001
Chapter/Region: NWIC
Location: Oly
Vehicle:
98 My FMIC
Is bigger than yours.

Default

Did you swap injectors around yet?
CosmoTheCat is offline   Reply With Quote
Old 08-10-2019, 05:34 AM   #9
pcampbell
Scooby Newbie
 
Member#: 437670
Join Date: Jan 2016
Location: VT
Vehicle:
2005 2.5 SC OB

Default

Yes sir, I swapped 1 and 3 including the pigtail for the Bosch injectors. Ecu still says misfire on 1 and only 1.
pcampbell is offline   Reply With Quote
Old 08-11-2019, 10:55 AM   #10
yarrgh
Scooby Specialist
 
Member#: 80465
Join Date: Jan 2005
Chapter/Region: RMIC
Location: Denver
Vehicle:
2001 2.5RS
Black Diamond Pearl

Default

Could be valves getting burned, you can check if a valve guide has started to migrate.
yarrgh is offline   Reply With Quote
Old 08-11-2019, 07:03 PM   #11
pcampbell
Scooby Newbie
 
Member#: 437670
Join Date: Jan 2016
Location: VT
Vehicle:
2005 2.5 SC OB

Default Cyl 1 misfire - changed plugs ,wires, coil

Hmmm how do I see that? Is it something you can see without dismantling? Look through exhaust port?? Wouldnít that affect leak down test results too?

Last edited by pcampbell; 08-11-2019 at 07:09 PM.
pcampbell is offline   Reply With Quote
Old 08-18-2019, 02:08 PM   #12
Freon-Peon
Scooby Newbie
 
Member#: 505152
Join Date: Aug 2019
Default

Are you getting any oil residue on the plug/wire? I had this happen due to valve cover gasket failure fouling the connection.
Freon-Peon is offline   Reply With Quote
Old 08-21-2019, 06:59 AM   #13
pcampbell
Scooby Newbie
 
Member#: 437670
Join Date: Jan 2016
Location: VT
Vehicle:
2005 2.5 SC OB

Default

Quote:
Originally Posted by Freon-Peon View Post
Are you getting any oil residue on the plug/wire? I had this happen due to valve cover gasket failure fouling the connection.


No oil that I can see. The spark plug tube seems dry.
pcampbell is offline   Reply With Quote
Old 08-23-2019, 07:37 AM   #14
pcampbell
Scooby Newbie
 
Member#: 437670
Join Date: Jan 2016
Location: VT
Vehicle:
2005 2.5 SC OB

Default

Going to check valve lash. Maybe it is a tiny bit tight.
pcampbell 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 03:17 AM.


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.