Welcome to the North American Subaru Impreza Owners Club Saturday September 22, 2018
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Built Motor Discussion

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 04-01-2017, 09:03 PM   #1
WilliHaM
Scooby Newbie
 
Member#: 453391
Join Date: Aug 2016
Unhappy 2002 WRX Forged 2.0, 20g Hesitation/Bucking

I have had this problem in the past and clearly have not fixed it while I thought it went away at times.

The car has many aftermarket parts and more recently seems to buck and hesitate under more boost but previously was only under hard throttle.

I am using a MBC and car is tuned for around 20lbs.

Does not sputter in 1st and is less often in 2nd. Logs show no knock during
during these pulls or time of hesitation. 3rd is most prevalent wit sputtering
pretty much any time over 35% throttle and higher lbs of boost.

Tests done so far:
Swapped MAF
Fixed MAF wiring
Swapped Plugs to stock heat range copper .30 (might have made things worse)
Check Fuel pressure by driving with fuel pressure kit hooked up to the outlet of fuel filter, pressure was around 65lbs with 15lbs of boost (under the
impression that this is slightly high)
A/F seems to jump up around .3 from 11 under boost when hesitation occurs

No CEL or seemingly other problems.

Will appreciate any suggestions to get to the bottom of this. Friends and Family have subarus so I can swap parts from them if need be. Any help is greatly appreciated!
* Registered users of the site do not see these ads.
WilliHaM is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 04-01-2017, 10:33 PM   #2
andyfloyd
Scooby Newbie
 
Member#: 87587
Join Date: May 2005
Vehicle:
2002 wrx
silver

Default

could it be coils going bad, would make sense as the higher gears put more load on the engine.
andyfloyd is offline   Reply With Quote
Old 04-01-2017, 11:35 PM   #3
WilliHaM
Scooby Newbie
 
Member#: 453391
Join Date: Aug 2016
Default

Quote:
Originally Posted by andyfloyd View Post
could it be coils going bad, would make sense as the higher gears put more load on the engine.
No misfire codes, no blinking check engine light. Still possible?
WilliHaM is offline   Reply With Quote
Old 04-01-2017, 11:58 PM   #4
isurfnj1
Scooby Specialist
 
Member#: 343367
Join Date: Jan 2013
Chapter/Region: Tri-State
Location: south jersey
Vehicle:
2002 rotated gt3076

Default

Quote:
Originally Posted by WilliHaM View Post
No misfire codes, no blinking check engine light. Still possible?
Happened to me like that on my last hybrid set up. So yes. Definitely possible.
isurfnj1 is offline   Reply With Quote
Old 04-02-2017, 12:00 AM   #5
junior1023
Scooby Newbie
 
Member#: 223393
Join Date: Sep 2009
Chapter/Region: RMIC
Location: Colorado Springs
Vehicle:
2015 WRX
Dark Grey Metallic

Default

Quote:
Originally Posted by WilliHaM View Post
No misfire codes, no blinking check engine light. Still possible?
I had a similar problem. My tuner (etune) told me that he was seeing a misfire on the logs I sent. Even though it wasnt throwing a code of any kind. Replaced all 4 coil packs (they were old anyway, 125,xxx miles) and the problem went away.
junior1023 is offline   Reply With Quote
Old 04-02-2017, 11:09 PM   #6
andyfloyd
Scooby Newbie
 
Member#: 87587
Join Date: May 2005
Vehicle:
2002 wrx
silver

Default

On a side note, my coils are getting old and I am thinking of replacing them ( going vf48 soon). Are people just going with OEM coils new to replace? You can find a set of 4 on fleabay ( not OEM ) for 80 bucks but Im assuming they are junk.
andyfloyd is offline   Reply With Quote
Old 04-03-2017, 01:23 AM   #7
monkeyposeur
Scooby Specialist
 
Member#: 333468
Join Date: Sep 2012
Chapter/Region: RMIC
Location: SLC, UT
Vehicle:
1993 SS
03 WRB GD 205/22T 20G-XT

Default

Is it possible you have a boost leak? Have you checked your grounds and battery terminal connections?

I would get new OEM coils if I was to get any.
monkeyposeur is offline   Reply With Quote
Old 04-03-2017, 10:16 AM   #8
WilliHaM
Scooby Newbie
 
Member#: 453391
Join Date: Aug 2016
Default

Appreciate the responses, I checked my coilpacks and one of four was the stock coilpack
(probably has the 250k miles like the car) while the others had DE DIAMONDS FK0333,
not sure how much better they actually are but apparently they are.

Replaced my #1 coilpack with another known working one from another 02 WRX and it
boosted strong to redline with higher boost levels and no hesitation. I believe this is the
problem at hand but will report back in a week to confirm.
WilliHaM is offline   Reply With Quote
Old 04-03-2017, 11:48 AM   #9
silvercookie
Scooby Specialist
 
Member#: 180033
Join Date: May 2008
Chapter/Region: Tri-State
Location: Queens, NY, 11385
Vehicle:
2005 WRX
PSM

Default

If it hasn't been said, probably wouldnt hurt to get new 02 sensors and a new MAF, or at least a clean.
silvercookie is offline   Reply With Quote
Old 04-03-2017, 11:49 AM   #10
silvercookie
Scooby Specialist
 
Member#: 180033
Join Date: May 2008
Chapter/Region: Tri-State
Location: Queens, NY, 11385
Vehicle:
2005 WRX
PSM

Default

Also definitely run OEM NGK iridiums. They are good for 400 whp or so. No reason to go with copper or platinum or anything else.
silvercookie is offline   Reply With Quote
Old 04-03-2017, 12:23 PM   #11
Samurai Jack
Scooby Guru
 
Member#: 21145
Join Date: Jul 2002
Chapter/Region: NESIC
Location: Not in my own time
Vehicle:
2002 Enemy of Aku

Default

Definitely sounds like the coil packs are your issue.


Quote:
Originally Posted by silvercookie View Post
Also definitely run OEM NGK iridiums. They are good for 400 whp or so. No reason to go with copper or platinum or anything else.
How can you make spark plug recommendations when you know nothing about his car?
Samurai Jack is offline   Reply With Quote
Old 04-03-2017, 12:26 PM   #12
Titter
Scooby Specialist
 
Member#: 416107
Join Date: Mar 2015
Chapter/Region: International
Location: Ontario, Canada
Vehicle:
2002 WRX Wagon
EJ207 Spec C 4EAT

Default

spark blow out is my guess
Titter is offline   Reply With Quote
Old 04-03-2017, 12:31 PM   #13
silvercookie
Scooby Specialist
 
Member#: 180033
Join Date: May 2008
Chapter/Region: Tri-State
Location: Queens, NY, 11385
Vehicle:
2005 WRX
PSM

Default

Quote:
Originally Posted by Samurai Jack View Post
Definitely sounds like the coil packs are your issue.




How can you make spark plug recommendations when you know nothing about his car?
How? Because a 20g on a 2.0 isnt making more than 350-375. More so on only 20psi.

And good job telling him what his issue sounded like after he confirmed what the issue was since you are in a pissy mood it seems like.
silvercookie is offline   Reply With Quote
Old 04-03-2017, 02:42 PM   #14
Samurai Jack
Scooby Guru
 
Member#: 21145
Join Date: Jul 2002
Chapter/Region: NESIC
Location: Not in my own time
Vehicle:
2002 Enemy of Aku

Default

Having a tantrum, are we?

No where did the OP state what his mods were other than a 20G? You have no idea what his power levels are.

STD practice is one grade colder plug for every 100HP increase.
350 - 375HP is well above the standard power levels of the EJ205
Samurai Jack is offline   Reply With Quote
Old 04-03-2017, 04:10 PM   #15
WilliHaM
Scooby Newbie
 
Member#: 453391
Join Date: Aug 2016
Default

Quote:
Originally Posted by Samurai Jack View Post
Having a tantrum, are we?

No where did the OP state what his mods were other than a 20G? You have no idea what his power levels are.

STD practice is one grade colder plug for every 100HP increase.
350 - 375HP is well above the standard power levels of the EJ205
Yes it's forged internals and all with a decent 20lb+ tune but I don't agree with the idea of different sparks anyway, I'm not tracking the car and do not plan on fouling plugs.

I have seen no evidence suggesting platinum or iridium gives a better charge than copper only that a step or two colder will allow me to run better with the side effect (to my knowledge) being more fouled plugs if driving in low rpms often or for extended amounts of time.

Thanks for both of your contributions though and hope this issue doesn't resurface with a newer coilpack in. Does anyone know where to buy coilpacks?
WilliHaM is offline   Reply With Quote
Old 04-03-2017, 08:45 PM   #16
andyfloyd
Scooby Newbie
 
Member#: 87587
Join Date: May 2005
Vehicle:
2002 wrx
silver

Default

Quote:
Originally Posted by WilliHaM View Post
Appreciate the responses, I checked my coilpacks and one of four was the stock coilpack
(probably has the 250k miles like the car) while the others had DE DIAMONDS FK0333,
not sure how much better they actually are but apparently they are.

Replaced my #1 coilpack with another known working one from another 02 WRX and it
boosted strong to redline with higher boost levels and no hesitation. I believe this is the
problem at hand but will report back in a week to confirm.

Awesome man!!! glad that was the issue. BTW for anyone looking into coils the Cosmo coils are 160 shipped and people seem to love them. They arent OEM but they are somehow cheaper and people are having great luck with them. Im gonna drop a set into my 257k ej205 haha.

Copper plus will actually work just as well, but they dont last as long, platinum will last longer and iridium will last the longest but you really dont see much difference between the 3 as far as power levels go. I do think a #7heatrange NGK is ideal at anything over 300whp.
andyfloyd is offline   Reply With Quote
Old 04-04-2017, 07:16 AM   #17
Samurai Jack
Scooby Guru
 
Member#: 21145
Join Date: Jul 2002
Chapter/Region: NESIC
Location: Not in my own time
Vehicle:
2002 Enemy of Aku

Default

Quote:
Originally Posted by WilliHaM View Post
Yes it's forged internals and all with a decent 20lb+ tune but I don't agree with the idea of different sparks anyway, I'm not tracking the car and do not plan on fouling plugs.

I have seen no evidence suggesting platinum or iridium gives a better charge than copper only that a step or two colder will allow me to run better with the side effect (to my knowledge) being more fouled plugs if driving in low rpms often or for extended amounts of time.

Thanks for both of your contributions though and hope this issue doesn't resurface with a newer coilpack in. Does anyone know where to buy coilpacks?
There is no evidence that copper / iridium / platinum are any better than the other. Choose the right plug for the application, in the same heat range, and you will get equal performance. As was mentioned, one lasts longer than the other.

Ultimately, you either buy copper ( the least expensive ) or the iridium ( the most expensive ) and you get the same overall service life. You just change copper more frequently. Some people change their plugs every 10000 miles, so copper is the better alternative for them.

I've never had any issues running one step colder plugs in a daily. Plugs run fine and look fine. This is on both 4 & 8 cylinder cars.

When I replaced my coil packs, I bought OEM Subaru from a dealer off of Amazon. I think they were ~ $350 shipped. Just had to do a little shopping around to find the best price.
Samurai Jack is offline   Reply With Quote
Old 04-04-2017, 09:12 AM   #18
insaneimpreza
Scooby Newbie
 
Member#: 83291
Join Date: Mar 2005
Location: NE PA
Vehicle:
1998 RSTi
IAG Stg4 Extreme S366SXE

Default

I had this happen once and mine was an injector clip that wasn't fully seated. Could also be a coil pack connector tho too. Go over all of them quick, at least its easy to start with.
insaneimpreza is offline   Reply With Quote
Old 08-06-2018, 03:33 AM   #19
Psycho-82
Scooby Newbie
 
Member#: 489746
Join Date: Aug 2018
Default

Just trying to confirm, was the solution the newer coil pack? I'm currently dealing with a similar issue on my 16 Sti... along with a heating issue... but that's for another time.
Psycho-82 is offline   Reply With Quote
Old 08-13-2018, 03:26 AM   #20
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 WilliHaM View Post
No misfire codes, no blinking check engine light. Still possible?
yep mine did that for a year before the light came on
subaru_gc8 is online now   Reply With Quote
Old 08-13-2018, 03:27 AM   #21
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 Psycho-82 View Post
Just trying to confirm, was the solution the newer coil pack? I'm currently dealing with a similar issue on my 16 Sti... along with a heating issue... but that's for another time.
I wouldnt think you would have problems yet, the op had a 2002. I would take yours back to the dealer and have them figure it out
subaru_gc8 is online now   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 02:33 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2018 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.