Page 2 of 2 FirstFirst 12
Results 21 to 36 of 36

Thread: 2014 silverado misfire

  1. #21
    Tuner in Training
    Join Date
    Mar 2020
    Posts
    23
    um also I cant get my cooling to kick on even trying to turn them on in hptuners.

  2. #22
    Tuner in Training
    Join Date
    Mar 2020
    Posts
    23
    Just found out the fans will turn on if I unplug the maf.
    The truck idles smooth but fans will not turn on but once I unplug the maf the fans kick on and it runs rough. But it doesn't die.

  3. #23
    Tuner in Training
    Join Date
    Mar 2020
    Posts
    23
    Added new map sensor. Also tried a vacuum test couldn't find any leaks. I have no clue what's going on.

  4. #24
    Senior Tuner
    Join Date
    Jan 2015
    Location
    Franklin, NC / Gainesville, Ga
    Posts
    4,412
    I thought you had this figured out and fixed already? Guess I missed something. If it's backfiring, then it's timing or valve train - pretty much it. Either reluctor spun on crank or the more likely - you have bad lifter and or bent push rods.

    This is of course you still have the same problem with all of the misfire, map and maf codes.
    2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
    2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80

    ~Greg Huggins~
    Remote Tuning Available at GHugginsTuning@gmail.com
    Mobile Tuning Available for North Georgia and WNC

  5. #25
    Tuner in Training
    Join Date
    Mar 2020
    Posts
    23
    Quote Originally Posted by GHuggins View Post
    I thought you had this figured out and fixed already? Guess I missed something. If it's backfiring, then it's timing or valve train - pretty much it. Either reluctor spun on crank or the more likely - you have bad lifter and or bent push rods.

    This is of course you still have the same problem with all of the misfire, map and maf codes.
    Only permanent codes, seems to run fine till it hits operating temp. Low on power but doesn't backfire till I hit operating temperature.

  6. #26
    Senior Tuner
    Join Date
    Jan 2015
    Location
    Franklin, NC / Gainesville, Ga
    Posts
    4,412
    Get a log while watching current cylinder misfires and misfire histories per cylinder

  7. #27
    Senior Tuner
    Join Date
    Jan 2015
    Location
    Franklin, NC / Gainesville, Ga
    Posts
    4,412
    Everything you're describing is pointing to a dead exhaust valve. Gas in oil misfires map sensor codes maf sensor codes and backfires

  8. #28
    Tuner in Training
    Join Date
    Sep 2021
    Location
    Lexington KY
    Posts
    42
    Quote Originally Posted by GHuggins View Post
    Everything you're describing is pointing to a dead exhaust valve. Gas in oil misfires map sensor codes maf sensor codes and backfires
    Or possibly a converter thats getting more and more clogged up.....especially since it gets worse after it warms up. I think he replaced the 02 sensors too because he had codes for it? A log will help a bunch

  9. #29
    Tuner in Training
    Join Date
    Mar 2020
    Posts
    23
    Quote Originally Posted by GHuggins View Post
    Get a log while watching current cylinder misfires and misfire histories per cylinder
    newestlog.hpl
    here is a short log.
    misfires in cylinders 1,3,5,7

    sorry it took so long to figure out how to set up the scanner to read it.

    I really hope this helps solve the problem.

    Thanks everyone for your time.

  10. #30
    Senior Tuner
    Join Date
    Jan 2015
    Location
    Franklin, NC / Gainesville, Ga
    Posts
    4,412
    Yep, driver's side pulling fuel whilst passenger's adding fuel with all cylinders on driver's bank misfiring. Estep got this one. Unbolt your exhaust if you can right at the collector and re-drive or just do a back pressure test - if you have this ability. You should even be able to do some wot stomps with everything bolted up and then unbolt and do a quick compare.

    Funny thing is - you usually don't see cats go all at once like this - usually over time...

    You can also have damaged O2's cause the same symptoms, but you've already replaced them, sooooo...
    2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
    2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80

    ~Greg Huggins~
    Remote Tuning Available at GHugginsTuning@gmail.com
    Mobile Tuning Available for North Georgia and WNC

  11. #31
    Tuner in Training
    Join Date
    Mar 2020
    Posts
    23
    Quote Originally Posted by GHuggins View Post
    Yep, driver's side pulling fuel whilst passenger's adding fuel with all cylinders on driver's bank misfiring. Estep got this one. Unbolt your exhaust if you can right at the collector and re-drive or just do a back pressure test - if you have this ability. You should even be able to do some wot stomps with everything bolted up and then unbolt and do a quick compare.

    Funny thing is - you usually don't see cats go all at once like this - usually over time...

    You can also have damaged O2's cause the same symptoms, but you've already replaced them, sooooo...
    sorry for the confusion about the o2 sensors but I "cleaned" them.

    So pretty good chance I ruined them.

  12. #32
    Senior Tuner
    Join Date
    Jan 2015
    Location
    Franklin, NC / Gainesville, Ga
    Posts
    4,412
    Wouldn't hurt to replace them at this point, but go ahead and unbolt and test - you may even be able to look down in it for damage. You should be able to take temperature readings too.
    2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
    2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80

    ~Greg Huggins~
    Remote Tuning Available at GHugginsTuning@gmail.com
    Mobile Tuning Available for North Georgia and WNC

  13. #33
    Tuner in Training
    Join Date
    Mar 2020
    Posts
    23
    Wanted to thank everyone for helping turns out both cats are better than 90% plugged and the o2 sensors were pretty nasty looking. I replaced the 02 sensors but the cats are too far gone. I'm still trying to lossen the exhaust bolts. My ⅜ impact just doesnt have the power to remove them. I lathered them in pb blaster and have a ? impact on the way. If I can't clean them while off the truck I will replace them with long tube headers and new cats.

    Thanks again everyone

  14. #34
    Senior Tuner
    Join Date
    Jan 2015
    Location
    Franklin, NC / Gainesville, Ga
    Posts
    4,412
    Trick for the nuts is to fire the engine up - wait until the coolant temp just starts to move off of it's cold mark - shut it off - soak it with the PB - then wait a couple or minutes to cool, but not completely then hit them with the 1/2 - usually come right off.
    2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
    2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80

    ~Greg Huggins~
    Remote Tuning Available at GHugginsTuning@gmail.com
    Mobile Tuning Available for North Georgia and WNC

  15. #35
    Potential Tuner
    Join Date
    Jun 2022
    Posts
    1
    Just piggy backing here, 2015 sierra 1500 6.2 dod delete from AMS, stage one cam, throws code P0011. What can I do to get this beast back on the road??

  16. #36
    Tuner in Training
    Join Date
    Sep 2021
    Location
    Lexington KY
    Posts
    42
    Quote Originally Posted by 3dgord View Post
    Just piggy backing here, 2015 sierra 1500 6.2 dod delete from AMS, stage one cam, throws code P0011. What can I do to get this beast back on the road??
    Check the oil pressure at the oil pressure sender.
    Check the number 2 cam bearing. this is where the oil is fed to the actuator. Did you do the lockout on the actuator? Also, check the connector on the harness near the vacuum pump on the engine front cover. they are known to have corrosion in the connector.


    One other thing to try. this is from an old GM bulletin. if none of this works, Id say you have a bad connection, bad Cam magnet, or actuator bolt (solenoid valve). heres the copied bulletin procedure.

    Use the GDS to actuate the cam phaser solenoid 4 or 5 times then try starting the vehicle.
    GDS steps

    1.1 Engine control module

    1.2 Control function

    1.3 Camshaft position actuator system

    1.4 Intake camshaft position actuator solenoid valve

    1.5 Cycle the solenoid 4 or 5 times then try to start the engine If the engine does not start go to the next step

    Begin by disabling ignition. Remove KR75 Engine Controls Ignition Relay located in the Under Hood Fuse Block in position 70 according to the fuse block lid map.
    Also disable fuel by removing the Fuel Pump relay in position 59 according to the fuse block lid map.

    Unplug the camshaft actuator to perform the following. Install a 20A fused jumper wire between the terminal 2 and 12V.

    Tickle/tap the low reference terminal 1 to ground (by using the correct test terminal from the Kit. (J-35616-65B)) on the cam actuator magnet, while cranking the engine over.

    Then try to start the engine. This may have to be performed more than once