backfiring?
Page 1 of 2 12 LastLast
Results 1 to 15 of 21

This is a discussion on backfiring? within the General Maintenance, Troubleshooting & Accidents. forums, part of the Tech & Modifying & General Repairs category; Its about 2500 miles after my rebuild was just going to do a log with my AP as soon as ...

  1. #1
    doa
    doa is offline
    Registered User
    Join Date
    Sep 2011
    Posts
    36

    backfiring?

    Its about 2500 miles after my rebuild was just going to do a log with my AP as soon as I got to about 5200 rpm it almost sounded like my exhaust was multi backfiring, I tried 3 other pulls not at WOT and it seemed to be building boost good but as soon as I got to around 51-5200 rpm it starts doing it.

  2. Remove Advertisements
    ClubWRX.net
    Advertisements
     

  3. #2
    Moderator Donkey's Avatar
    Join Date
    Apr 2005
    Location
    Da boonies
    Posts
    6,150
    I Support ClubWRX
    Need more info........
    ***How to Ask a Technical Question!**
    Resident Adviser @ WTF Tuning, LLC
    2002 FORESTER S
    1998 FORESTER S




  4. #3
    doa
    doa is offline
    Registered User
    Join Date
    Sep 2011
    Posts
    36
    This is all the info I have, I have no clue where to even start. Like I said I was going to do my first pull in the car after the rebuild and as soon as I approached 5k rpm there was a rapid amount of backfiring coming from the exhaust, I tried twice more and the same thing. I didn't bring the rpms any higher because I have no clue what it was.

  5. #4
    Master Baiter EJ257's Avatar
    Join Date
    Aug 2007
    Location
    On a stream bank somewhere
    Posts
    19,768
    I Support ClubWRX
    Modifications?
    2005 WRX STi (Mods | Virtual Dyno)

    Resident Tuner @ WTF Tuning

    "Never trust anything that bleeds for a week and lives ..."

    UNYSOC

  6. #5
    Registered User Killerkanadian's Avatar
    Join Date
    Mar 2012
    Location
    Oklahoma
    Posts
    116
    Checked your A/F Ratio?

  7. #6
    doa
    doa is offline
    Registered User
    Join Date
    Sep 2011
    Posts
    36
    From what the AP says its around 14.7 at idle did not check it when this had happened and do not really want to do it again incase it will cause damage. Stage 2 + sf are my mods. Could it possibly be the ecu cutting fuel? My AP read 16.5psi was the max boost, I wasn't even WOT probably a little less. Maybe boost leak, vaccum leak or intake manifold leak?

  8. #7
    doa
    doa is offline
    Registered User
    Join Date
    Sep 2011
    Posts
    36
    Just attempted another pull and threw a misfire code in 2 and 4. It felt like the car was surging. Pull was done from 2nd gear 3k to 5k and 3rd gear to 5k.

  9. #8
    Master Baiter EJ257's Avatar
    Join Date
    Aug 2007
    Location
    On a stream bank somewhere
    Posts
    19,768
    I Support ClubWRX
    Quote Originally Posted by doa
    Just attempted another pull and threw a misfire code in 2 and 4. It felt like the car was surging.
    IF YOU HAVE A MISFIRE CODE ,PLEASE READ THIS!!!
    2005 WRX STi (Mods | Virtual Dyno)

    Resident Tuner @ WTF Tuning

    "Never trust anything that bleeds for a week and lives ..."

    UNYSOC

  10. #9
    doa
    doa is offline
    Registered User
    Join Date
    Sep 2011
    Posts
    36
    My dad seems to think its the maf because the car is surging. Can any old sensor cleaner be used?

  11. #10
    Moderator T0rque's Avatar
    Join Date
    Dec 2004
    Location
    Medford, Oregon
    Posts
    25,521
    I Support ClubWRX
    nope, you need maf sensor cleaner


    Lead Wrench @ WTF Tuning, LLC

  12. #11
    Registered User teflon_jones's Avatar
    Join Date
    Apr 2007
    Location
    8000' up in Colorado
    Posts
    6,753
    Quote Originally Posted by T0rque View Post
    nope, you need maf sensor cleaner
    Well it depends what he means by "any old sensor cleaner." Electronics spray cleaner is the same stuff and 1/2 the price if there's a Radio Shack near you. Apparently if you put "MAF" on the label it costs twice as much...
    Scott
    Past Subies - '11 STI Limited stage 1+ and '04 STi stage 2+
    '13 Wrangler Rubicon - custom front bumper w/12k lb winch & off-road lights, skid plates, diff guards, etc.
    '04 Porsche 911 Turbo GT2 clone 600 HP/TQ
    '77 F-150 heavily modded for off-roading

  13. #12
    doa
    doa is offline
    Registered User
    Join Date
    Sep 2011
    Posts
    36
    Im going to change fuel pump and plugs tomorrow with one step colder ngks, anyone know the perfect gap for our cars on these plugs. Hopefully it is not the coil packs or the o2 sensors but with my luck it most likely is.

  14. #13
    Registered User teflon_jones's Avatar
    Join Date
    Apr 2007
    Location
    8000' up in Colorado
    Posts
    6,753
    Leave the gap on the plugs they come with.

    Did you try cleaning the MAF yet?
    Scott
    Past Subies - '11 STI Limited stage 1+ and '04 STi stage 2+
    '13 Wrangler Rubicon - custom front bumper w/12k lb winch & off-road lights, skid plates, diff guards, etc.
    '04 Porsche 911 Turbo GT2 clone 600 HP/TQ
    '77 F-150 heavily modded for off-roading

  15. #14
    Moderator T0rque's Avatar
    Join Date
    Dec 2004
    Location
    Medford, Oregon
    Posts
    25,521
    I Support ClubWRX
    did you read the threads posted above??


    Lead Wrench @ WTF Tuning, LLC

  16. #15
    doa
    doa is offline
    Registered User
    Join Date
    Sep 2011
    Posts
    36
    Yes I read through them I have yet to change the fuel pump and plugs and do anything for that matter. Here is a log of me merging on the highway, anything that looks out of the norm to point me in the right direction. https://docs.google.com/spreadsheet/...0ak9TWWc#gid=0

    I would just start buying stuff and replacing it but I just dropped 6k on a complete rebuild of this engine and dont really have the budget to start guessing.

Page 1 of 2 12 LastLast

Posting Permissions

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