CEL & Fuel setup Questions
+ Reply to Thread
Results 1 to 11 of 11

This is a discussion on CEL & Fuel setup Questions within the General Maintenance, Troubleshooting & Accidents. forums, part of the Tech & Modifying & General Repairs category; 2006 WRX Wagon - bone stock. I get phantom cylinder misfires - cylinders 1 and 3 are the most common. ...

  1. #1
    Registered User
    Join Date
    May 2013
    Posts
    27

    CEL & Fuel setup Questions

    2006 WRX Wagon - bone stock.

    I get phantom cylinder misfires - cylinders 1 and 3 are the most common. I've replaced the fuel pump with a Walbro 255lph unit, I replaced the fuel filter with a Subaru OEM new filter, I replaced the fuel strainers (both sides), I've tightened down all of the fuel line clamps (intake manifold was off) and used Gorilla Glue to try to negate the chances of the fuel line clamps coming loose. I have also replaced the fuel injector o-rings and run a few bottles of fuel system cleaner. I did replace the coil boot (not the pack itself, but the rubber stem that connects to the spark plug) with new Denso units. I've also replaced the spark plugs with Denso units - properly gapped (0.029).

    My setup is simple:
    Factory intake, factory TD04, factory intercooler, PTP turbo blanket, factory exhaust from the heads to the muffler.

    The only modification that I've done (which actually helped) was adding an engine grounding kit (a la Paranoid Fabrications).

    I have tried swapping the coil packs around, but the problem stays mainly at cylinders 1 and 3.

    I've been debating either replacing the coil packs, but I am reluctant as if it does not resolve it - I've just dropped a lot of cash for nothing.

    I've also been looking into changing the fuel delivery system from series (2, 4, 1, 3) to parrallel (1 and 2 then 3 and 4). I'm trying to find a way to relocate the factory fuel pressure regulator, but have had little success on that front.


    So, I'm curious if anyone else has run a similarly (99% stock) setup and had similar issues. If yes, what resolved it? If no, any recommendations?

    Thanks!

  2. Remove Advertisements
    ClubWRX.net
    Advertisements
     

  3. #2
    Moderator Donkey's Avatar
    Join Date
    Apr 2005
    Location
    Da boonies,Va
    Posts
    6,492
    I Support ClubWRX
    Resident Adviser @ WTF Tuning, LLC
    2002 FORESTER S
    1998 FORESTER S




  4. #3
    Registered User
    Join Date
    May 2013
    Posts
    27
    after reading over the list, and recalling all that i've done previously to resolve this - it boils down to:
    vacuum leaks
    PCV blowby
    valve clearances

    i'll be pulling off the intake manifold to replace the turbo and intake pipe next week - at that time, i'll replace the vacuum lines for the turbo and check all of the hoses (just to be safe). i'll see about mounting the oil catch can as well to help negate the blowby (i know i have some blowby - i've seen oil inside the intercooler).

    i can't check the valve clearances myself, so i'll have to take it to a shop to get that done.

    i'll report back my findings.

  5. #4
    Registered User
    Join Date
    May 2013
    Posts
    27
    did not put the catch can on.

    did replace the turbo (such a hassle).

    did replace the vacuum lines with high quality silicone vacuum lines. now i get a near constant misfire on cylinder 2... the car feels like it is stumbling almost constantly.

    i do have some near smoke rising up from the turbo area - my guess is the oil return hose OR the gasket for the oil return pipe. if it is the gasket, that is entirely my fault - i did not purchase one ahead of time (brain fart there), so i used a Toyota Oxygen Sensor gasket (near identical shape and size).

    so... i get to remove the turbo again this weekend and see if it is the hose or the gasket - in either case, i am replacing both. just highly, highly annoyed that i have to do this again.

  6. #5
    Registered User
    Join Date
    May 2013
    Posts
    27
    this past weekend, i replaced all of the vacuum hoses and replaced nearly all of the PCV hoses and clamps.

    found an exhaust leak (the cross pipe was not fully tightened), so that is fixed now.

    both upstream and downstream oxygen sensors were replaced.

    the turbo oil return hose and gasket were both replaced with new pieces. the original turbo oil hose was the problem - it was not going on straight to the return feed.

    smoke appears to be completely gone.

    the stumbling/stuttering still happens above 4000rpms. this really has me puzzled. it never had this previously. either it was a faulty rebuild of the turbo, i have a vacuum leak somewhere, one or more of the coils is bad or the wiring harness needs to be repaired.

  7. #6
    OMG WTF MainFrame's Avatar
    Join Date
    Sep 2002
    Location
    Texas, United States
    Posts
    9,027
    I Support ClubWRX I Support ClubWRX
    So the misfire was always on 1 and 3, regardless of which coilpack you had on them, and now it's always on #2? That seems very odd.

    Usually valve lash being off will result in noisy valves.. do they seem abnormally noisy? (for a subaru I mean, they're already pretty noisy anyways)


    Going to parallel fuel lines usually causes more misfires than the stock arrangement, so I wouldn't mess with that.

    Do you have a way of data logging the engine, or pulling a look at learning view? Have you tried performing a boost leak test to hunt down any possible leaks?

  8. #7
    Registered User
    Join Date
    May 2013
    Posts
    27
    when the factory clutch, flywheel and crank pulley were on the vehicle - it would get misfires usually on 1 and 3 - rarely on 2 or 4, but it did happen.

    i have the exedy organic clutch and replacement flywheel. still getting misfires on all 4 cylinders - randomly, but mainly 1 and 3.

    the engine is quieter now then it has ever been (replacing the hoses helped) - valvetrain and all.

    at this point, i am not touching anything under the hood.

    i have the Torque app - i will see if it allows data logging. if it does, i'll report back the findings.

  9. #8
    Registered User
    Join Date
    May 2013
    Posts
    27
    to try and troubleshoot the issue, i started the engine and began spraying carb cleaner all around - while watching the Air/Fuel Ratio on my phone. when i sprayed under the intercooler on the driver side the AFR went from 14.7 to 13.0 - dead giveaway of an air/vacuum leak.

    i removed the intercooler and found 1 of the clamps was not securely on (from the secondary air pump to the Y splitter), so i put the clamp on correctly and checked the 2 ends of the Y pipe - everything is on tight.

    i put the intercooler back on - idling is fine. under acceleration (foot BARELY touching the gas) the whole car shudders and bucks like a wild bronco - in every gear.

    so, i limped the car home - the whopping 500 feet. and it is just sitting now. i'll get some more carb cleaner to see if i missed something.

    i am just very, very confused and frustrated.

  10. #9
    OMG WTF MainFrame's Avatar
    Join Date
    Sep 2002
    Location
    Texas, United States
    Posts
    9,027
    I Support ClubWRX I Support ClubWRX
    I would put a boost leak tester on the intake, pressurize the whole system to about 20psi, and listen for any leaks..

  11. #10
    Registered User
    Join Date
    May 2013
    Posts
    27
    i am having the car towed to LIC tomorrow. i don't have the time to troubleshoot it and have it be non-operational.

    so, they'll fix it, i'll pay the bill - and other than spark plugs, the air filter and oil filter - i won't be going into the engine bay anymore.

    i'll save all my wrench time for my Mr2 and Starlet. those are not my daily drivers, so if they're down for a bit, it doesn't matter all that much.

  12. #11
    Registered User
    Join Date
    May 2013
    Posts
    27
    so... LIC did a HUGE job on my WRX. absolutely props to those guys for an amazing job!

    firstly, yes, boost leak. was resolved by removing a gasket that was not needed.

    secondly, thanks to Subaru for using hollow stemmed (filled with sodium) valves, my exhaust valve seats were trashed.

    thirdly, the 'wonderfully' light Exedy flywheel was removed.


    the short of it. due to the crap design of the hollow stemmed (sodium filled) valves and the way too light flywheel, yeah... plenty of misfires. the flywheel did not CAUSE the misfires, but with the condition of my exhaust valves, it did not help.

    my wife and i picked up the car today and despite the near 80 miles of driving, the check engine light never came on. this is NOT normal compared to previous.

    a ton of other small things were addressed (none of which would cause nor impact the check engine light nor misfire). i drove the WRX roughly 20 miles... it has never felt so smooth or healthy.

    i won't go into detail of everything that was done, but suffice to say, any work that gets done to my WRX will be by the hands of LIC.

    is LIC the cheapest? no. are they worth the money? ABSOLUTELY.

    i went back and forth with Noah over details (because i read way too much) - he spent the time to tell me his experience and what DOES and DOES NOT work, based upon the total experience of LIC.

    there are a few things that he and i absolutely agreed upon without question - upgraded head gaskets, upgraded head studs, stock flywheel, new valve train, new exhaust gaskets and hardware, etc.


    so... in the end, i have a WRX that runs amazingly well. again, it has never felt better or more healthy (even at 86k miles when i originally purchased it).

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself. We strongly suggest that you stay away from using aol, yahoo, msn, and hotmail accounts. Sometimes the mail server blocks the emails from our server. As a result you will not receive any notifications including the confirmation email.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •