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Thread: Help the New Guy Gen 4 Corvette - Idle goes to hell after tune

  1. #1
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    Help the New Guy Gen 4 Corvette - Idle goes to hell after tune

    Ok, so I have been going step by step with my tune after mods. I have done both MAF & VE tuning more than once. After I log and tune my idle goes to hell. Not sure what I am doing wrong. I have started from scratch twice now. Any suggestions would be appreciated.

    2009 Corvette LS3 A6 Base 14K Miles: Vararam Snake Charmer CAI, Livernois Motorsports Cam/Springs ect - Stage 2C
    Intake Lift 224@.050
    Exhaust Duration 236@.050
    Intake Lift .620"
    Exhaust Lift .620"
    LSA 117

    Livernois Ported Heads & PFADT Series Tri-Y Long Tube Header & X-Pipe w/Cats

    HP Tuner Pro setup.

    Thanks, Jeff
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  2. #2
    Have you looked at this? It might help you..https://forum.hptuners.com/showthrea...light=big+mike

  3. #3
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    add 5 deg of timing in your idle rpm and g/s areas in ECM 12612.

    your car sure does like to run warm, geez. maybe shes ridiculously lean. check the plugs, two cents. this will confirm lean condition. cools off a bit a speed tho, nbd.

    So it looks to me like you've made changes to the VVE table alone, no changes to MAF table.

    Maybe you left the car in blended mode, did some runs, then changed your VVE according to your blended fuel trims.

    If that's the case, start from scratch and do MAF only then VVE only, then re-enable blended mode.

    Looks like you increased min air to get it to idle, makes sense.

    If you don't adjust VVE and MAF seperately, they will fight each other and it will run like crap.

  4. #4
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    I give these a try today. I haven't adjust cooling temps yet, is this necessary? Not running a lower temp thermostat for DD.

  5. #5
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    So I started from scratch, again. Followed the link from Bill and just did a MAF only tune/part throttle. Have my WB reading Lambda, looking good. Went with Ed M suggestion to change STOICH to 14.08 for E10.
    Question? So I plan on going to VE tuning now? Should I do MAF WOT tuning first or after the VE part throttle? Runs great right now at higher throttle and I haven't even looked at the trans or torque tables. Any suggestions? I think I am on track now. Thanks
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    Last edited by jfiely; 3 Days Ago at 06:19 PM.

  6. #6
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    I'd do the VE next, driving in the same conditions etc. Then re-enable both and work on the idle, prolly. Don't worry about WOT for now, get it driving normal and reliable on the street, idling good with the AC on . Don't mess with the trans for now, get fueling in line for part throttle and idle (best you can).

    And when i say work on the idle, I mean make the changes to the MAF table after maf tuning (most idle areas will be around 26-2800 hz), then put it in SD, drive it around (not like a mad man, just normal), then make the changes to the VVE cofficients and put it back in blended mode an dsee how it idles.


    You know you have part throttle driving right when you LT trims are +/- 2, you push the throttle to accelerate and it instantly goes. No lag, no hesitation, idles consistent. with the same trims. And it will sound more throaty from the engine/intake vs sounding like header exhaust noise when the fueling is right. just my observations with my TBSS. There is a fine line on getting MAF and VE in line, when you have it, you know it.
    Last edited by bmd2_colo; 3 Days Ago at 10:00 PM.

  7. #7
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    add 10-15% to ECM 13624, it might help any lean spots/hesitation during gear shift. helps my TBSS

    - do this after MAF and VE are adjusted to your liking. If it goes too rich according to your wideband (13 afr), you may have too much in. If it goes lean ( >14.5) during tip in/ gear shift with constant tps hold, you have too little. Either rich or lean will feel laggy and slight hesitation during shift/ tip in. Id adjust this after fueling is on. Just my 2 centsp. That being said, the car will tell you what it likes. If it likes it a bit rich, leave it there. You just wanna get rid of the shift/tip in lag. Also, it may/ may not need the entire table adjusted, maybe just certain areas.

    There is also burst knock and some delta airmass stuff that affects shifting/ tip in, but for bow just get the fueling in line, normal driving, no crazy accelerations, do not get into PE and be aware when DFCO is active so you can ignore that data, or take it into account if you want. These initial MAF/VVE sessions are important, they’re the foundation of everything else, so be consistent
    Last edited by bmd2_colo; 3 Days Ago at 06:43 AM.

  8. #8
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    Quote Originally Posted by jfiely View Post
    I give these a try today. I haven't adjust cooling temps yet, is this necessary? Not running a lower temp thermostat for DD.
    Not necessary for now,imo. Your car has a PWM fan, right? Im at the airport not in front of my laptop

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    Question?

    Not sure I understand ?add 10-15% to ECM 13624?.

  10. #10
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    Yes it does have the PWM fan. I only upped the fan % by temp, slightly. Thanks

  11. #11
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    No worries. I mean your stomp factor. Use the navigator (ctrl-N) enter 13624, it will access that table

  12. #12
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    That vette is prolly pretty quick. Im about to stuff a cam in the tbss, similar specs to yours, bit smaller tho

    That idle tuning guide looks legit, i look forward to tryin that out once I get basic fueling in line and take a look at injector timing adjustments once I change some stuff (maybe) based on new valve events and 5 deg of overlap
    Last edited by bmd2_colo; 3 Days Ago at 11:19 AM.