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Thread: LSJ issues...wot and idle

  1. #1

    LSJ issues...wot and idle

    Hey guys, kinda new still on tuning lsj's, but I'm having an issue with my buddies lsj at wot. At about 5200 rpm's the afr goes from 11.5 slowly down to 10.0 by 5800 rpm's. I've tried everything that I could think to do and nothing is working. Last month we did some logs and everything looked good, except the wot afr, and it bogged hard up top. Today the fuel trims were off a bit but it basically did the same thing, except I got the bogging to stop.

    Also at idle, the timing jumps around and I think that's what is causing the idle to jump around. But I don't know how to adjust for a smooth idle timing. I've tried a few things but nothing has worked.

    I'm at a loss guys, any help here? I have attached the tune and the last log of today.

  2. #2
    Advanced Tuner laser_racer's Avatar
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    Fuel trims will change day to day so if they are close don't worry. I would bet the cat warm up is on or piston protect under the pe tab.

  3. #3
    Post more info on the supporting mods. That log is pretty ugly looking man. There are quite a few things that need to be changed in the tune as well, but more info on the supporting mods is needed.

    Plus I'm at work so it's hard for me to go into long in depth details at the moment.
    09 Cobalt SS - E47+EFR6758 =

    07 Silverado ECSB LBZ Duramax - Bunches of goodies

  4. #4
    intake, ported sc & tb, 60's, 2.8 pulley

  5. #5
    Advanced Tuner laser_racer's Avatar
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    Well you got few problems one thing you need to do is log the commanded afr so you can see what the car is trying to command. Also the fuel trims are pretty off at idle. Where did you get your injector tables?

  6. #6
    The injector spreadsheet. I've been trying tro dial in idle for ever, no matter what I chnage on the maf for it, it's always off...

  7. #7
    You unfortunately have far bigger issues than the idle to worry about with that tune friend. For starters the ungodly amount of misfires you have needs to be addressed, the timing tables are all sorts of funky (which when fixed can help your idle control a bit better), your throttle control table is so wild I don't know how the car isn't going into limp mode and some of your torque management tables are funky.
    09 Cobalt SS - E47+EFR6758 =

    07 Silverado ECSB LBZ Duramax - Bunches of goodies

  8. #8
    What do you mean throttle control table? Most of the tables on here are the same as when we first started tuning. The only tables I have done any changes to so far are maf, ve, idle, timing and pe. This car has been a nightmare from the beggining, but I'm using it to learn. The misfires have always been present too, replaced plugs and helped a little bit but still not enough. Obviously lol

    I'm, just at a total loss on what to do.

  9. #9
    I read through the one thread where Area47 helped out 06 sic's tune. I compared his file to mine, but I don't see where his would run any better than mine. Idk I'm a noob lol

  10. #10
    the maf should increase smoothly. i imagine that the airflow values are pretty far off. as they are definitely way off from mine, and i have the same mods. maybe you should even clean the maf sensor. youre probably running ve if the maf hasnt ever been replaced or cleaned. lots of misfires with good fueling tables usually equates to a ve table thats way off and not smooth. at least it did for me.

    also, the short pulse adder doesnt go along with the spread sheet values. not sure how much that would help / hurt though.

  11. #11
    Advanced Tuner laser_racer's Avatar
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    You can give these injector settings a go they seem to work pretty good for all the 60 tunes I have done.

  12. #12
    Thanks Laser! Those actually helped a lot, mixed in with the timing changes from
    area47's tables! But the car is still misfiring like crazy, don't know what could be causing it? Runs way smoother and harder, idles like a gem! I told him to do a vacuum leak test, hopefully that will help cure some of the issues. What else could we try here? He just recently replaced his spark plugs.

  13. #13
    Advanced Tuner omega_5's Avatar
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    Oh jeez... where to start.

    First, things first. If you're going to copy from the injector spreadsheet, copy all the tables, and copy them properly. From what I'm seeing, only the flow rate was copied. The offset and pulse adder are from some strange source.

    Airflow tables should be smooth. Your MAF is probably causing 99% of the WOT issues. The VE table is no beauty either. As well, the low RPM region is running quite rich, you might want to do some sub-2500rpm tuning. Rolling through a parking lot helps get that part of the MAF and VE in line. Tune that area by itself.

    Spark tables are too hot for your setup. Just because someone gives you tables that might work, doesn't mean you should use them. Listen to the guys giving you advice here, they know what they're talking about.
    On the topic of spark tables.... your idle is all effed up cause someone effed up the idle tables. See the "idle adaptive spark control" tables? put those back to stock, and never touch them again. Same goes for the "idle spark advance" tables. It makes me want to punch puppies when people modify those and ask why their idle is all messed.
    Oh... and go into the high and low octane tables, and put columns 0-1024 back to stock, and blend up to 1792. You don't need to advance this area, the LSJ is not a low RPM torque monster, and is not designed to be beat on below 2000rpm. This will also improve the idle quality.
    Tyler

  14. #14
    Also put your ETC TPS Max back to stock! This is the table I was refering to a few posts back. There is no need to have the entire table set to 100%. This might help clear up some of your misfire issues as well.
    09 Cobalt SS - E47+EFR6758 =

    07 Silverado ECSB LBZ Duramax - Bunches of goodies

  15. #15
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    Quote Originally Posted by omega_5 View Post
    Oh jeez... where to start.

    First, things first. If you're going to copy from the injector spreadsheet, copy all the tables, and copy them properly. From what I'm seeing, only the flow rate was copied. The offset and pulse adder are from some strange source.......
    Sorry to Hijack old thread But I used your spreadsheet and came up with the exact same numbers as OP????


    Quote Originally Posted by omega_5 View Post
    On the topic of spark tables.... your idle is all effed up cause someone effed up the idle tables. See the "idle adaptive spark control" tables? put those back to stock, and never touch them again. Same goes for the "idle spark advance" tables. It makes me want to punch puppies when people modify those and ask why their idle is all messed.
    ........
    I also chenged these tables but only because I read

    2006 LSJ Cobalt Idle Issues
    http://www.hptuners.com/forum/showthread.php?t=36578


    I am kinda lost here, and this car was prev. tuned so I dont have the stock file.

  16. #16
    Senior Tuner cobaltssoverbooster's Avatar
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    bone stock and 42# gmstg2
    now you have both
    Attached Files Attached Files
    2000 Ford Mustang - Top Sportsman

  17. #17
    Senior Tuner
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    Quote Originally Posted by cobaltssoverbooster View Post
    bone stock and 42# gmstg2
    now you have both
    Thanx I downloaded a supposedly stock file from repos. but yours is different yet.

    I will take a better look tomorrow, going home to drink this headache away for the night lol.