Hesitation and bucking

Discussion in 'Mazdaspeed 3 Troubleshooting' started by Jacob Bernacki, Apr 24, 2020.

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  1. Jacob Bernacki

    Jacob Bernacki Greenie N00B Member

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    Hey guys, just created an account here. I’ve had a 2010 speed3 for about 3-4 years. It’s full bolt on, tuned by Freektune, and I’ve been noticing a bucking/hesitiation intermittently, on either cruising speeds or light throttle acceleration. Spark plugs are brand new itv22s. Any help would
    Be appreciated. I have two data logs here that where I was experiencing this bucking. Thanks
     

    Attached Files:

    Jacob Bernacki, via an iPhone, Apr 24, 2020
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  2. Awafrican

    Awafrican Moderator Gold Member

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    When you say it bolt on are you including IM, exhaust mani, and turbo as those are technically bolt-ons as well.

    Did the problem start after you changed the plugs or did you change them trying to resolve the issue? Any other recent work on the car? If so start by checking all the affect areas for their connections.
     
    Awafrican, via a mobile device, Apr 25, 2020
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  3. Jacob Bernacki

    Jacob Bernacki Greenie N00B Member

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    Turbo Xs Catless downpipe, SRI, TIP, Cobb fmic, greddy boost controller, fidanza flywheel, turbo smart bov and cork sport hpfp internals.This winter I had put on a stock ported mani with the egr delete, vtcs delete, catch can, cleaned the valves and rebuilt the turbo. Although the problem was subtle last year, this year its slowly getting worse. Tried replacing the spark plugs, tried a known good maf sensor but it just seems to always come back. It’s super random and intermittent. Just gets annoying when I’m cruising down a highway at a steady speed and getting what seems like a quick misfire
     
    Jacob Bernacki, via an iPhone, Apr 25, 2020
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  4. Solarsurge

    Solarsurge Greenie Member

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    I’m not really sure what I’m supposed to be looking at in your logs. Seems perfectly normal to me at first glance unless you aren’t lifting off the throttle and it’s dropping on its own. If that’s the case, I’d check the battery. Low battery will cause throttle cuts like that.


    Sent from my iPhone using Tapatalk
     
    Solarsurge, via a mobile device, Apr 27, 2020
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  5. Jacob Bernacki

    Jacob Bernacki Greenie N00B Member

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    Ya I don’t really know what I’m looking at in the logs either. I’m not lifting on the throttle at all. Was actually accelerating until I needs to shift. I’ll take a look at the battery and the alternator!
     
    Jacob Bernacki, via an iPhone, Apr 27, 2020
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  6. Raider

    Raider Administraider Administrator Platinum Member

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    Where are you sourcing your plugs ?
     
    Raider, via a mobile device, Apr 27, 2020
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  7. Jacob Bernacki

    Jacob Bernacki Greenie N00B Member

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    The densos were from a local parts store, GAP (Guelph auto parts). And the NGKs before that were also from a local parts store, APC
     
    Jacob Bernacki, via an iPhone, Apr 27, 2020
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  8. Jacob Bernacki

    Jacob Bernacki Greenie N00B Member

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    I also have just noticed that my LTFT at idle is 16% and the STFT will sit at 5-6%. Is that not too high for idle?
     
    Jacob Bernacki, via an iPhone, Apr 27, 2020
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  9. SharksInSpace

    SharksInSpace Planets and shit. Silver Member

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    That's a bit high for LTFT, yeah. Positive trims mean a vac leak.
     
  10. Jacob Bernacki

    Jacob Bernacki Greenie N00B Member

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    Ya I thought so. I hooked up a vacuum gauge and it’s reading a steady 20 inches of vacuum. I would assume a vac leak wouldn’t get those values
     
    Jacob Bernacki, via an iPhone, Apr 27, 2020
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