Page 1 of 2 12 LastLast
Results 1 to 20 of 27

Thread: Turbo ls6 backfires and pops in boost???

  1. #1

    Turbo ls6 backfires and pops in boost???

    Just as title says I have a turbo ls6 with a few issues. I can get about one smooth pull through the rpms then it starts running crappy and breaking up resulting in poping and backfiring from the exhaust. I'm including the current tune and a log...I can't tell anything different from a clean pull to a breaking up pull. Maybe I am missing something. 80 lb injectors s475 turbo
    Silverstone 93 Mazda Rx-7 ls-6 swap

  2. #2
    I think it may be heat affecting my pass plug wires causing misfire
    Silverstone 93 Mazda Rx-7 ls-6 swap

  3. #3
    Advanced Tuner WS6HUMMER's Avatar
    Join Date
    Feb 2006
    Location
    Pineville La. US
    Posts
    771
    What plug and what's the gap?
    99 T/A WS6, original LS1 turbo

  4. #4
    typical tr6's I'd have to check the gap but i think somewhere around .035 if that sounds right. Its werid cause another local guy had a similar issue with his turbo ta. It will pull fine then all of a sudden its alomst like a whole side is missing
    Silverstone 93 Mazda Rx-7 ls-6 swap

  5. #5
    Advanced Tuner WS6HUMMER's Avatar
    Join Date
    Feb 2006
    Location
    Pineville La. US
    Posts
    771
    Quote Originally Posted by dark-one View Post
    typical tr6's I'd have to check the gap but i think somewhere around .035 if that sounds right. Its werid cause another local guy had a similar issue with his turbo ta. It will pull fine then all of a sudden its alomst like a whole side is missing
    How much boost are you running at that gap?
    99 T/A WS6, original LS1 turbo

  6. #6
    less than 8 psi Just trying to get things figured out. Nice build btw...I like you built mine myself Fabbing and all.
    Silverstone 93 Mazda Rx-7 ls-6 swap

  7. #7
    Advanced Tuner WS6HUMMER's Avatar
    Join Date
    Feb 2006
    Location
    Pineville La. US
    Posts
    771
    Quote Originally Posted by dark-one View Post
    less than 8 psi Just trying to get things figured out. Nice build btw...I like you built mine myself Fabbing and all.
    Thanks

    Gap is a hair wider than I'd run it but not your problem I think. Do you have a wideband on the car?
    99 T/A WS6, original LS1 turbo

  8. #8
    Sure do...It should be in that log on the first post...I'm still quite rich 10.8 at wot in spots
    Silverstone 93 Mazda Rx-7 ls-6 swap

  9. #9
    Advanced Tuner WS6HUMMER's Avatar
    Join Date
    Feb 2006
    Location
    Pineville La. US
    Posts
    771
    Just looked at your tune, your open loop EQ ratio table still has multipliers in it, it should be all set to 1.0
    99 T/A WS6, original LS1 turbo

  10. #10
    Advanced Tuner WS6HUMMER's Avatar
    Join Date
    Feb 2006
    Location
    Pineville La. US
    Posts
    771
    I'm also guessing that you have a boost referenced FPR by looking at your flow rate table, right?
    99 T/A WS6, original LS1 turbo

  11. #11
    That would explain some bizarre commanded ratios i've seen at times.
    Silverstone 93 Mazda Rx-7 ls-6 swap

  12. #12
    Its just running off 39psi at the rail now not referenced yet as I have plenty of fuel now...Its a a1000 pump return setup
    Silverstone 93 Mazda Rx-7 ls-6 swap

  13. #13
    Advanced Tuner robbyredneck's Avatar
    Join Date
    Jan 2010
    Location
    fingerlakes ny
    Posts
    356
    what do you meen not referenced? your flow rate vs kpa is telling your pcm it is. i am assuming ford lu80s right? how does it idle? sorry for more questions than info. just noticing some parts of your tune. hard to tell where the problem is even occuring from your scan

  14. #14
    I'm just running a staic pressure of 39psi aka the port on the regulator is not hooked up. It idled alright till i took out the open loop adders. And I agree the scans are not showing me anything as far as to whats going on with it. Injectors are the siemens deka 80lbers
    Silverstone 93 Mazda Rx-7 ls-6 swap

  15. #15
    Advanced Tuner robbyredneck's Avatar
    Join Date
    Jan 2010
    Location
    fingerlakes ny
    Posts
    356
    i would think open loop adders until your up to operating temp then have it set to 1. and definately hook up your regulator to a reference. think of it like this. at 50kpa its pulling fuel out of the injector and at 140 kpa its trying to push boost into it but at either of these conditions your computer thinks the fuel flowing through the injector is the same. you must be damn close ve wise or tuned the fudge out of it to get there cause' your wideband looks pretty good. just my 2cents. keep this thread going i love inspired swaps. have you seen snypers car. nissan may want to hire him.

  16. #16
    I have just been logging the ve error and correcting it each time and repeating...Something else i've noticed is the 4 degrees of knock everytime it goes into boost. I have a feeling it is false and probably has to do with some pipe making noise on something as everything in the car is so close.
    Silverstone 93 Mazda Rx-7 ls-6 swap

  17. #17
    Advanced Tuner robbyredneck's Avatar
    Join Date
    Jan 2010
    Location
    fingerlakes ny
    Posts
    356
    if it's knocking then it will be going into low octane table. usually procedure is to copy high table into low.

  18. #18
    Advanced Tuner WS6HUMMER's Avatar
    Join Date
    Feb 2006
    Location
    Pineville La. US
    Posts
    771
    Quote Originally Posted by dark-one View Post
    Its just running off 39psi at the rail now not referenced yet as I have plenty of fuel now...Its a a1000 pump return setup
    Thats your problem then, you need to scale them for that fixed pressure until you reference the FPR.
    99 T/A WS6, original LS1 turbo

  19. #19
    Advanced Tuner WS6HUMMER's Avatar
    Join Date
    Feb 2006
    Location
    Pineville La. US
    Posts
    771
    Quote Originally Posted by dark-one View Post
    I have just been logging the ve error and correcting it each time and repeating...Something else i've noticed is the 4 degrees of knock everytime it goes into boost. I have a feeling it is false and probably has to do with some pipe making noise on something as everything in the car is so close.
    With your injectors scaled for 0 MAP across the table and not referenced to boost you may be having actual knock, I bet if you tuned the VE table to compensate your duty cycle is through the roof.

    Quote Originally Posted by robbyredneck View Post
    if it's knocking then it will be going into low octane table. usually procedure is to copy high table into low.
    He has an upgraded OS, for speed density, you dont have to do that unless your running a stock GM OS. The low octane table works like a normal CL MAF setup with the upgraded OS so just incase you do get bad fuel it will hopefully save the engine.
    99 T/A WS6, original LS1 turbo

  20. #20
    Should i reference it with a check valve so it only ups the reg with boost
    Silverstone 93 Mazda Rx-7 ls-6 swap