Thread: Help with idle misfire tuning

Results 1 to 4 of 4
  1. #1 Help with idle misfire tuning 
    SE Level Member
    Join Date
    Nov 2008
    Location
    Syracuse
    Posts
    2
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Does anyone have any tips for idle misfire tuning? I have an 04 Comp G with a VS cam, 39lb cobra injectors, 85mm MAF and the usual other stuff. I never had idle misfire issues until I installed the cam. Cyl 5, 4 and 3 are the worst for misfire counts. The car runs great and the misfires only happen at idle. I see in tiny tuner there is a rough idle injector skew table. has anyone tried skewing the injectors either way to help. I see the #3 is already skewed to 102% stock. I tried increasing the idle timing up to 25 with my HPT but it really made no difference. The firing order is 165432 so when cyl's 5,4,3 start misfiring it makes for a pretty rough idle. any advice would be appreciated.
    Reply With Quote  
     

  2. #2 Re: Help with idle misfire tuning 
    Turbo is the way to go. Fivefingerdeathpunch's Avatar
    Join Date
    Sep 2009
    Location
    Rogers, MN
    Posts
    21,030
    Thanks (Received)
    21
    Likes (Received)
    45
    Dislikes (Received)
    0
    well just so you know this. Once a 3800 is fairly modded, idle misfires are just gunna be part of the game, and you cant stop it from happening.

    Tho it seems like you have a little worse case with having many many misfires.

    How do your plugs look, are the wires in good shape?

    What gap are you running and what plugs aswell?

    SMGPFC Member #1
    Reply With Quote  
     

  3. #3 Re: Help with idle misfire tuning 
    SE Level Member
    Join Date
    Nov 2008
    Location
    Syracuse
    Posts
    2
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    I'm using AL104 plugs and the wires are Delco's less than a year old. The car is wideband tuned so I'm not super rich so fouling shouldnt be an issue. I see no misfires above 1200 rpm at all.

    Before I installed the cam my fuel trims at idle were arould -1 now after the cam install when it first starts to idle the trims are still -1 the when the misfires start the go to -8 obviously to counter the presumed richness of the unburned fuel. in affect making the other injectors leaner. which inturn I believe makes the misfiring worse.

    I'm really curious what the rough idle injector skew table does. if anything
    Reply With Quote  
     

  4. #4 Re: Help with idle misfire tuning 
    GTP Level Member 01gpgt01's Avatar
    Join Date
    Apr 2010
    Location
    Hagerstown,Md
    Posts
    1,933
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    If it doesnt set the CEL i wouldnt worry with it.
    2001 GT. A few here and there mods http://www.streetfire.net/video/2001...ynp_208097.htm

    2009 Hummer H3 Solar flare premium
    Reply With Quote  
     

Similar Threads

  1. unreported misfire at idle
    By 02bluegtss in forum 3.8L V6 Supercharged (L67)(L32)
    Replies: 7
    Last Post: 05-29-2011, 10:02 PM
  2. Odd rough sound at idle...possible misfire?
    By Spartanzz in forum 3.8L V6 Supercharged (L67)(L32)
    Replies: 7
    Last Post: 02-09-2011, 01:06 AM
  3. Another idle surge/misfire problem with multiple codes
    By Justinzoso in forum 3.8L V6 Naturally Aspirated (L36)(L26)
    Replies: 6
    Last Post: 06-04-2010, 11:43 AM
  4. Random dieing at idle + occasional misfire = me pissed off
    By mark455 in forum 3.8L V6 Naturally Aspirated (L36)(L26)
    Replies: 6
    Last Post: 04-22-2009, 09:22 PM
  5. Replies: 5
    Last Post: 05-11-2008, 07:10 PM
Tags for this Thread

View Tag Cloud

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