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 > 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 01-23-2009, 04:14 PM   #1
aclver1
Scooby Specialist
 
Member#: 114177
Join Date: May 2006
Chapter/Region: RMIC
Location: SLC utah
Vehicle:
2004 Impreza 2.5rs
70 Datsun Fairlady

Default delta cams and mis fires.

I had some delta cams 1000 grind installed a few weeks ago and I started getting misfires on random cylinders. I have a lw flywheel and lw crank pulley so it may be that but I got the 1000 grids so i would have less chances of having issues. It had a mis fire CEL right after we got it put back together and I reset the code and didn't have one for about 350 miles so I wasn't worried. I readjusted the valve lash because it was ticking like crazy and about 3 days later I got a p0301,p0303 and a p0304 code. Is there a chance that if I have the valve clearance set to tight, that it would cause a misfire? I just want to make sure it's not really a misfire, if it is just because of the flywheel or pulley it's fine, i just don't want there to be an issue.
* Registered users of the site do not see these ads.
aclver1 is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 01-23-2009, 04:25 PM   #2
shanemono4
Scooby Specialist
 
Member#: 173332
Join Date: Mar 2008
Chapter/Region: RMIC
Location: UT
Vehicle:
2003 2.5rs
PSM.

Default

hmmmmmm... I don't know if those are the codes that lightweight flywheels and pulleys throw. You sure it's not a misfire? when was the last time you did plugs and wires?
shanemono4 is offline   Reply With Quote
Old 01-23-2009, 04:31 PM   #3
sa4baru
Scooby Specialist
 
Member#: 195354
Join Date: Nov 2008
Location: State College, PA
Default

my deltacams have been throwing misfire codes since day one. i just keep a scanguage in the car to clear the codes that show up at least once a week...
sa4baru is offline   Reply With Quote
Old 01-23-2009, 04:51 PM   #4
aclver1
Scooby Specialist
 
Member#: 114177
Join Date: May 2006
Chapter/Region: RMIC
Location: SLC utah
Vehicle:
2004 Impreza 2.5rs
70 Datsun Fairlady

Default

I have a code scanner and i can reset them I just wanted to make sure it wasn't really a misfire. Is there any way to tell?
aclver1 is offline   Reply With Quote
Old 01-23-2009, 04:56 PM   #5
Qman
Scooby Specialist
 
Member#: 964
Join Date: Feb 2000
Chapter/Region: NWIC
Location: Bonney Lake, Wash. USA
Vehicle:
'95 work in
progress

Default

The computer reads it as a misfire. It isn't but the ecu is kind of picky sometimes. We are finding that most who have lwfw and pulleys are getting codes almost automatically. Just one or the other is about 50-50. What did you set your lash to?
Qman is offline   Reply With Quote
Old 01-23-2009, 04:56 PM   #6
fastenova
Scooby Specialist
 
Member#: 38829
Join Date: Jun 2003
Chapter/Region: NWIC
Location: Tigard, OR
Vehicle:
Not your usual 1997
Legacy GT

Default

Quote:
Originally Posted by aclver1 View Post
I have a code scanner and i can reset them I just wanted to make sure it wasn't really a misfire. Is there any way to tell?
Yeah, I'm beginning to think that they just do that. How does the car run?
fastenova is offline   Reply With Quote
Old 01-23-2009, 04:57 PM   #7
doubledribble
Scooby Specialist
 
Member#: 42912
Join Date: Sep 2003
Chapter/Region: MAIC
Location: Newark, DE
Vehicle:
2003 Outback Sport
bird **** & door dings

Default

is the tapping still there? does it run smooth? if it's not riding abnormally it's probably just the ECU.

simple, but have you checked your plugs?
doubledribble is offline   Reply With Quote
Old 01-23-2009, 05:10 PM   #8
aclver1
Scooby Specialist
 
Member#: 114177
Join Date: May 2006
Chapter/Region: RMIC
Location: SLC utah
Vehicle:
2004 Impreza 2.5rs
70 Datsun Fairlady

Default

It has a lumpy idle but anything over 1000rps is seems to be fine, i figured the idle is just the cams. The tapping is gone and it sounds good, I had the lash set to .006 for the intake and .008 of the exhaust but my feelers are tapered on the ends so I thin they are .002 smaller on the tip so if I didn't have them in all the way they could be off. I wouldn't imagine that .002 would make that much of a difference. I haven't checked the plugs so maybe that will be my next step.
aclver1 is offline   Reply With Quote
Old 01-23-2009, 05:11 PM   #9
fastenova
Scooby Specialist
 
Member#: 38829
Join Date: Jun 2003
Chapter/Region: NWIC
Location: Tigard, OR
Vehicle:
Not your usual 1997
Legacy GT

Default

Quote:
Originally Posted by aclver1 View Post
...I had the lash set to .006 for the intake and .008 of the exhaust
Isn't that too tight?
Quote:
Originally Posted by fastenova View Post
I'm looking at the FHI factory service manual and it says that valve lash for the 2.5L DOHC/SOHC motor should be:
Intake: 0.20 ± 0.02 mm (0.0079 ± 0.0008 in)
Exhaust 0.25 ± 0.02 mm (0.0098 ± 0.0008 in)

Last edited by fastenova; 01-23-2009 at 05:13 PM. Reason: neenjah
fastenova is offline   Reply With Quote
Old 01-23-2009, 06:23 PM   #10
aclver1
Scooby Specialist
 
Member#: 114177
Join Date: May 2006
Chapter/Region: RMIC
Location: SLC utah
Vehicle:
2004 Impreza 2.5rs
70 Datsun Fairlady

Default

I read that is was .011 and .015 but for a regrind on cams it was .006 to .008 for intake and .008 to .0010 for exhaust depending on the grind. The first time i adjusted them I did .008 and .0010 and that is when it was ticking like crazy so I went to .006 and .008 and the is no ticking at all. If it is set too low would that cause a misfire? should I set it to .007 and .009?
aclver1 is offline   Reply With Quote
Old 01-24-2009, 02:29 PM   #11
watchunglava
Scooby Specialist
 
Member#: 168862
Join Date: Jan 2008
Chapter/Region: NESIC
Location: Portland Maine
Vehicle:
2007 ej253n/a 5speed
Red Sox Nation Lifer

Default

a misfire is an ignition problem. its timed with your crank and piston position.

if your getting a misfire, its either , the plugs the wires the coil pack the ecu .

or you could have a compression issue , cracks , leaks , ?

or lastly and most likely is your afr is out of wack because of the cams install.

what are you using for engine management?
watchunglava is offline   Reply With Quote
Old 01-24-2009, 03:13 PM   #12
Skidd
Scooby Specialist
 
Member#: 1853
Join Date: Jul 2000
Chapter/Region: TXIC
Location: SA-TX (Hozer expat)
Vehicle:
GC6 Supercharged
STM

Default

I get misfire codes with my 2000 grind Delta Cams and a 14lb ACT Flywheel (and many other mods). I was working on a recent theory that it was my AFPR, but that has not panned out. It has helped the idle situation with a correctly set FPR though . Prior to installing my 14lb FW, I never used to get misfire codes with the delta cams ( and a 900 rpm idle) I repeat.. NEVER!!!. But, since the LWFW went in, I cant' seem to quite stop them. It might take a week for it to happen, but the 0301-0304 codes usually come back. And it always happens while sitting at a red-light. Oh yeah, and I currently have my lash set at 0.08 and 0.10.
Skidd is offline   Reply With Quote
Old 01-24-2009, 08:35 PM   #13
watchunglava
Scooby Specialist
 
Member#: 168862
Join Date: Jan 2008
Chapter/Region: NESIC
Location: Portland Maine
Vehicle:
2007 ej253n/a 5speed
Red Sox Nation Lifer

Default

if your geting misfire at idle its most likely because your not giving it enough fuel. richen the mix see if it helps
watchunglava is offline   Reply With Quote
Old 01-24-2009, 08:43 PM   #14
sniper1rfa
Scooby Specialist
 
Member#: 141040
Join Date: Feb 2007
Chapter/Region: BAIC
Location: Designing things
Vehicle:
07 2.5i wagon
UGM

Default

isn't the combination of a lightweight flywheel and lightweight pulling combined notorious for causing misfire codes anyway?

I recall reading something about the accel. and decel. on the crank being too fast, causing the ECU to throw a misfire.


EDIT: nevermind, reread your post - you addressed that. This convo is over my head.
sniper1rfa is offline   Reply With Quote
Old 01-24-2009, 08:55 PM   #15
watchunglava
Scooby Specialist
 
Member#: 168862
Join Date: Jan 2008
Chapter/Region: NESIC
Location: Portland Maine
Vehicle:
2007 ej253n/a 5speed
Red Sox Nation Lifer

Default

yea i hear the lightweight flywheel / pulley combo is no good. i run a light weight pulley , if i had the combo i would shoot myself in any traffic.

you probably need a stand alone ecu if you wanna run a race set up. there is only so far modifying the stock goodies will get you.
watchunglava is offline   Reply With Quote
Old 01-24-2009, 11:12 PM   #16
ten80
Scooby Specialist
 
Member#: 53625
Join Date: Jan 2004
Location: AK
Vehicle:
00 16' FXT

Default

I ran a lightweight flywheel and pulley with my delta cams on my 03 TS and had to remove the pulley so that the car would idle normally at 700rpm and removing the pulley greatly improved the smoothness of the engine. No idea about misfire CELs since I had a persistant catalytic converter CEL.
ten80 is offline   Reply With Quote
Old 01-25-2009, 01:49 AM   #17
Skidd
Scooby Specialist
 
Member#: 1853
Join Date: Jul 2000
Chapter/Region: TXIC
Location: SA-TX (Hozer expat)
Vehicle:
GC6 Supercharged
STM

Default

Quote:
Originally Posted by watchunglava View Post
if your geting misfire at idle its most likely because your not giving it enough fuel. richen the mix see if it helps
What? richen the mix? uh.. yeah.. I'll get right out there with my screw driver, set of idle jets and try that? How exactly do you propose we richen the mix? The fact is, the ECU is pulling fuel at idle mostly due to the lack of vacuum caused by a lumpy cam. Closed loop STFT and LTFT are in the negative. So, if anything.. it's too rich.
Skidd is offline   Reply With Quote
Old 01-25-2009, 03:03 AM   #18
watchunglava
Scooby Specialist
 
Member#: 168862
Join Date: Jan 2008
Chapter/Region: NESIC
Location: Portland Maine
Vehicle:
2007 ej253n/a 5speed
Red Sox Nation Lifer

Default

Dude u tell me then? Lol.

My motors not misfiring.

U even said it that your pulling fuel at idle. So I was correct then in telling you your mix is too lean.

If you have a lack of vaccum then that's an issue. Do you have lower vaccum under load as well . Or just at idle?
watchunglava is offline   Reply With Quote
Old 01-25-2009, 10:31 AM   #19
Skidd
Scooby Specialist
 
Member#: 1853
Join Date: Jul 2000
Chapter/Region: TXIC
Location: SA-TX (Hozer expat)
Vehicle:
GC6 Supercharged
STM

Default

Quote:
U even said it that your pulling fuel at idle. So I was correct then in telling you your mix is too lean.
Actually, no.. that's backwards.. if the ECU is pulling -20% LTFT in closed loop, then it's an indication of the AF being too rich.

I'm not pulling fuel, the ECU is pulling fuel due to the O2 sensor in closed loop detecting a rich condition. That's what STFT and LTFT is all about. The only thing I can do is change the fuel pressure to find the setting the ECU likes the best. (currently 39psi static). The ECU is in 100% full control of AF targets. The only way to change the AF targets in closed loop is to modify the ECU directly (open tune, access port, i-speed). And the only one that works on my car is the i-speed flash.

As for a lack of idle vaccum, it idles and sits nicely at 18-19Hg waiting at a stop light. In fact, it's not even rough given the modified cams. When you change the way a cam is to perform, it's offen a sacrifice of something. In this case, it's a rougher idle.

Here is the kicker.. I don't have a misfire either!! But, due to the things that I've done to my car, my idle is no longer stock smooth. The ECU is way too picky about idle smoothness, and throws misfire codes when a mouse farts next door! It's almost a 50:50 change, that if you put cams in your car, you might throw a code, and you might not. I did not throw any codes (with 950 idle) until adding the LWFT.

Last edited by Skidd; 01-25-2009 at 11:00 AM.
Skidd is offline   Reply With Quote
Old 01-25-2009, 12:49 PM   #20
watchunglava
Scooby Specialist
 
Member#: 168862
Join Date: Jan 2008
Chapter/Region: NESIC
Location: Portland Maine
Vehicle:
2007 ej253n/a 5speed
Red Sox Nation Lifer

Default

well its not too rich when the ecu is pulling fuel lol!!!!!

open source doesnt work for your car? thats way too bad .

i was going to suggest the fuel pressure next , but you seem to have it all figured out.

irridium plugs are supposed to ignite the mixture better and more complete maybe give them a try.

or swap out your ecu for a more modern one that open sorce works with . same motor should be pretty easy neigh?
watchunglava is offline   Reply With Quote
Old 01-25-2009, 01:04 PM   #21
Skidd
Scooby Specialist
 
Member#: 1853
Join Date: Jul 2000
Chapter/Region: TXIC
Location: SA-TX (Hozer expat)
Vehicle:
GC6 Supercharged
STM

Default

Correct.. if the ECU is pulling fuel to match it's target AF, then it "should" not be the fuel mixture. Unless the ECU can't pull or add enough fuel. But, I watch my STFT and LTFT every time I get into my car (see pic below), and the LTFT never goes below 22-23% while the STFT sits around +-5%. But, sometimes it takes the ECU a few moments to detect the rich condition and pull enough fuel, then for the LTFT to learn that condition. But, once the LTFT is set, it runs like a champ... but.. with the odd misfire code! D'Oh!

OpenSource doesn't work on any of the JECS ECUs (99-01). Only the Denso ECUs. I believe that means the OS tune is only good for 02+ (or was it 03+? can't remember).

Plus, I'm way to cheap to drop for Irridium plugs!! Besides, the good ol NGK coppers have just always worked great in my car. I might try the irridiums.. but.. we'll see. Remember.. that I'm 99% sure it's not a true misfire, but rather the ECU "thinking" it's a misfire. So.. plugs should not be an issue.

ECU Swap is not a trivial thing at all. My car is a MAP car, and most of the NA ECUs that are OS tunable are MAF cars. So right away the wiring is going to be way different. Then there is the whole SOHC vs DOHC issue. The cam sensor position is different on each, so I'd need a custom cam sprocket. Blech! Basically, I'm stuck with what I have until I make a decision for piggy-back ecu.

How I watch my fuel trims
Skidd is offline   Reply With Quote
Old 01-25-2009, 01:21 PM   #22
watchunglava
Scooby Specialist
 
Member#: 168862
Join Date: Jan 2008
Chapter/Region: NESIC
Location: Portland Maine
Vehicle:
2007 ej253n/a 5speed
Red Sox Nation Lifer

Default

true that i thought 98-07 was pretty much the same deal. guess not
watchunglava is offline   Reply With Quote
Old 01-30-2009, 12:06 AM   #23
staticfritz
Scooby Specialist
 
Member#: 66934
Join Date: Jul 2004
Chapter/Region: NWIC
Location: Seattle WA
Vehicle:
2004 JBP FXT
2002 cammed OBS - RIP

Default

I've had cobbs spicy cams (~ delta 200's) in since early 05 (almost at a 4yr anniversary!) lwfw the whole time, stock crank pulley. ganzflo intake, brullen EL headers, highflow cat, stromung resonated exhaust. over the course of those fours years, i've replaced plugs, wires, coils, 1 set of headgaskets (popped the radiator, overheated bad), and gotten an ispeed reflash almost2 yrs ago.

I have Always gotten misfire codes with regularity. after four years of driving it, i'm pretty sure it's not actually misfiring.
unfortunately i can't change my idle (2002) to see if that takes care of it.
staticfritz is offline   Reply With Quote
Old 01-30-2009, 12:20 AM   #24
2.5i
Scooby Specialist
 
Member#: 112986
Join Date: Apr 2006
Chapter/Region: NWIC
Location: Camano Island
Vehicle:
N/A Cam'd & Cornfed
DOM TUNED 06 Impreza

Default

In all honesty I am sure the cams have some to do with it, but mixing it with lw crank pulley and lw flywheel. You motor is pissed try removing the lw crank pulley and I gets better and doesn't throw as many codes.
2.5i is offline   Reply With Quote
Old 01-30-2009, 11:36 AM   #25
sa4baru
Scooby Specialist
 
Member#: 195354
Join Date: Nov 2008
Location: State College, PA
Default

i and my tuner have not figured out how to correct the misfire&cam issue. he says that he does not have access to the closed loop idle solenoid map (iirc) which is what he needs to get to in order to fix this. I have a 2005 drive by wire btw. the car is tuned, runs great above 2000 rmps, but the idle is all F'd up. the idle target is 1400 but it settles between 800 and 1200. i get misfires when it is below 1000, moreso towards 800. I was thinking it needs fuel at idle, but there's no way to get it there with the maps we have access to...
sa4baru 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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Delta cams and emissions testing in MA DNut New England Impreza Club Forum -- NESIC 4 03-06-2009 01:19 PM
The strangness mis-fire figured out. scoobi02 Mid Atlantic Impreza Club -- MAIC 7 09-28-2004 09:49 AM
Mis-Firing System install Elleipein Engine Management & Tuning 6 04-04-2003 04:22 PM
Bee R Rev Limiter with mis-fire system K3TR Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 4 02-06-2003 07:59 PM

All times are GMT -4. The time now is 10:14 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.