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Thread: srt 6.4L - shaking while mid throttle

  1. #1
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    srt 6.4L - shaking while mid throttle

    Hi,

    I have a problem with 2016 scat pack. While mid-trhrottle the car does not have full power and is shaking a little. while WOT I don't see it, but maybe that;s because there is higher RPM and I just don't feel it.

    I see that, the injector duty cycle is a little off left-right side when the shaking can be felt. It could be seen on the log.

    Any idea where to start looking for the source of the problem?



    chall-inj-duty.png
    challanger 6.4 injector issue.hpl

  2. #2
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    pegged the knock sensor

    its pulling over 10 degree KR outta it at 1/4 throttle 1250 rpm for some reason


    *2 outta 3 times it did... odd it did not do it all 3???
    Last edited by LilSick; 07-19-2023 at 01:21 PM.

  3. #3
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    Hi. I've just found the same.... Will try better fuel at first.

  4. #4
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    what fuel was in it?

    add the channels 'actual spark' and 'accelerator pedal effective position' to your log

  5. #5
    Advanced Tuner Josue Galban's Avatar
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    Quote Originally Posted by lambda1 View Post
    Hi,

    I have a problem with 2016 scat pack. While mid-trhrottle the car does not have full power and is shaking a little. while WOT I don't see it, but maybe that;s because there is higher RPM and I just don't feel it.

    I see that, the injector duty cycle is a little off left-right side when the shaking can be felt. It could be seen on the log.

    Any idea where to start looking for the source of the problem?



    chall-inj-duty.png
    challanger 6.4 injector issue.hpl
    do the test with a better fuel, if you have any configuration such as a cam, a bad support, an imbalance in the tires, this can affect the knock sensor, focus on preventing the knock sensor from reading, maybe they are loose in case it continues to do the same shit, turn them off and it works with good fuel and acceptable spark advance without abusing it. and everything worked.

  6. #6
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    Fuel is just regular EU 95 octane. The car is a new purchase and it was working fine for a few weeks. The issue just came out suddenly a few days ago.
    I hope it is the shitty Schell Vpower fuel

  7. #7
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    our shell gas is NITRO POWER lol

    (no, its not... but that is what is says on the pump)

  8. #8
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    Better fuel did not help.

    I will look for the knocking source. I am not sure about what mods are in the engine. Do you know how to check if there's an aftermarket camshaft? Sorry guys of its obvious, I'm familiar with ford's and gm mainly....

  9. #9
    Advanced Tuner N2speed's Avatar
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    Aftermarket cam will not make it knock like that,


    www.n2speed.com
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  10. #10
    Advanced Tuner Josue Galban's Avatar
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    Quote Originally Posted by lambda1 View Post
    Better fuel did not help.

    I will look for the knocking source. I am not sure about what mods are in the engine. Do you know how to check if there's an aftermarket camshaft? Sorry guys of its obvious, I'm familiar with ford's and gm mainly....
    It doesn't exactly have to cause problems, do the following turn off your knock sensor completely go for part throttle and wot take the whole board and go down -4* spark advance go test and feel if it makes any kind of vibration

  11. #11
    Advanced Tuner Josue Galban's Avatar
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    Quote Originally Posted by lambda1 View Post
    Better fuel did not help.

    I will look for the knocking source. I am not sure about what mods are in the engine. Do you know how to check if there's an aftermarket camshaft? Sorry guys of its obvious, I'm familiar with ford's and gm mainly....
    Believe me you have problems, it's only with the sensors, they are not working correctly, check if they are loose, go to a store, the sensors are just below the headers

  12. #12
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    Hi.

    Turned out the knocking was not the source of the problem. The sensors were detecting knock due to the shaking of the engine. Now the knocking is gone.
    I had broken EVAP valve to manifold hose. I replaced the EVAP and the hose. It is better, but, the problem still occurs.
    I made some logging and I noticed, that it happens every time the MAP reaches it's maximum value, which is ~110kPa, which is weird, sinse barometric pressure is 99kPa.

    I put MAP from other car, and problem is still occurring, so it is not the MAP sensor problem.

    Any idea where to look for?

    Log and tune attached.
    Attached Files Attached Files

  13. #13
    Senior Tuner veeefour's Avatar
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    Id say you have cracked ring land

  14. #14
    Quote Originally Posted by lambda1 View Post
    Hi.

    Turned out the knocking was not the source of the problem. The sensors were detecting knock due to the shaking of the engine. Now the knocking is gone.
    I had broken EVAP valve to manifold hose. I replaced the EVAP and the hose. It is better, but, the problem still occurs.
    I made some logging and I noticed, that it happens every time the MAP reaches it's maximum value, which is ~110kPa, which is weird, sinse barometric pressure is 99kPa.

    I put MAP from other car, and problem is still occurring, so it is not the MAP sensor problem.

    Any idea where to look for?

    Log and tune attached.
    How does the engine sound at idle? Smooth, rough, any loud noises? I see that Bank 1 knock sensor is higher than bank 2 but both seem way too high for low rpms, mine could be different. I also see that injectors are hitting 10ms, are you lightly accelerating or flooring the car? The 10ms is not normal for light acceleration (Yes knock adds fuel to stop detonation) but its rather high.

    Personally, I would find out what is done to the car and do a health check on all cylinders to ensure leak down is good and compression is good.

  15. #15
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    Engine runs smooth on idle and while driving. Problem is only when MAP reaches 110kPa.

    Will do the health check first. Sometimes it throws white smoke on startup for like one second.