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Thread: Idle timing

  1. #1
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    Idle timing

    Can anyone shed some light why idle timing has a setting of 60 degreees? While an LPG car has realistic figures for idle timing.
    Tune with actual data not simulated data!.....Applied Road/track Tuning

  2. #2
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    It may be a maximum allowed limit rather than a desired value.

    I base this assumption off the values in the "Low Load Maximum" table which has the same spark values and is described as, "This table provides a maximum spark limit when under low load conditions in relation to the time that the engine has been operating at low load".

    As with all assumptions I could be completely wrong.

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    The two idle tables aren't used at idle but do form part of the calculation. The ford spark strategy, in most cases, will use the lowest timing value out of a given calculation.

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    Quote Originally Posted by IH8TOADS View Post
    The two idle tables aren't used at idle but do form part of the calculation. The ford spark strategy, in most cases, will use the lowest timing value out of a given calculation.
    Thank's for the responses. Given what you have said I will see if I can get control of the idle timing today.

    Puffwagon, great foot note!
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    Quote Originally Posted by IH8TOADS View Post
    The two idle tables aren't used at idle but do form part of the calculation. The ford spark strategy, in most cases, will use the lowest timing value out of a given calculation.
    I had a look at the PCM code and they do not appear to be referenced at all. All the tables in this screenshot are referenced in the spark routine except for the "Spark low load maximum", "Spark Idle In Gear ECT" and "Spark Idle In Park/Neutral". I believe this is why they are all set to 63 from the factory.



    I may be wrong and they are accessed indirectly somehow but I can't seem to see where.

    It appears we are missing another table for cold start idle timing, you can modify cold start when you aren't at idle but there is another routine that controls the idle timing when cold. I tried to find it but no such luck yet.
    Last edited by rolls; 07-11-2016 at 08:17 PM.

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    Rolls, I use the idle tables on every single tune I do. I can assure you they are referenced.

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    Quote Originally Posted by IH8TOADS View Post
    Rolls, I use the idle tables on every single tune I do. I can assure you they are referenced.
    Interesting. So changing them from a value of 63 to something lower will actually limit the idle timing? Are you able to send me a .hpt file where you find they are used? Curious if it is only some strategies that use them, if not then I'd like to figure out how they are referenced as nothing addresses those locations where as all the other tables are referenced directly.

    edit: seems they are accessed differently to the other tables.
    Last edited by rolls; 07-11-2016 at 10:29 PM.

  8. #8
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    Quote Originally Posted by IH8TOADS View Post
    The two idle tables aren't used at idle but do form part of the calculation. The ford spark strategy, in most cases, will use the lowest timing value out of a given calculation.
    It responded exactly as you said it would, thank's
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    On my cammed Barra with 0.65 spark gap and e85 I run a measly 6 degree of advance at idle. I don't usually run more than 10 to 12 degrees on a Barra. My Evo's i'm down around 5 degrees.

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    Quote Originally Posted by IH8TOADS View Post
    On my cammed Barra with 0.65 spark gap and e85 I run a measly 6 degree of advance at idle. I don't usually run more than 10 to 12 degrees on a Barra. My Evo's i'm down around 5 degrees.
    Other than it adjusting the actual rpm what are the advantages to running more/less timing at idle?

    Do you know how to increase the idle timing at cold start? Mine runs -2 to 0 degrees for the first few minutes which is super loud. I've managed to stop it running warmup timing at cruise but not at idle. I could try disabling cold start entirely but not sure I want to do that.

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    Idle stability and prevents misfires. It won't affect RPM.

    I would have to check what HP can access and if so what's it's called in HP language.

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    Quote Originally Posted by IH8TOADS View Post
    Idle stability and prevents misfires. It won't affect RPM.

    I would have to check what HP can access and if so what's it's called in HP language.
    Less timing prevents misfires or more?

    Why does it prevent misfires?

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    Less advance will prevent misfires/popping. The rpm is low therefore you don't need to run 20ish degrees advance (like 99% of people tuning Barra's) and I don't care for emissions.

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    Quote Originally Posted by IH8TOADS View Post
    Less advance will prevent misfires/popping. The rpm is low therefore you don't need to run 20ish degrees advance (like 99% of people tuning Barra's) and I don't care for emissions.
    Cheers for the info.

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    IH8TOADS I tried editing those tables on my car and confirmed it changes nothing. I set them from 63 deg to 0 deg just to check and nothing changes at idle or neutral when cruising.

    Perhaps they are only used on the auto cars?

    Spark Min idle only appears to be used in open loop idle, eg if you put the car in neutral when you are going more than 5kph it will use this ignition number, once stopped it ignores the number and uses closed loop idle ignition timing.

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    It will work, you're doing something wrong or your software is f u c k e d.

    I have used it on BA to FG manuals, it works.Setting to zero is not a good test for spark in this case, set to 10.

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    Quote Originally Posted by rolls View Post
    I had a look at the PCM code and they do not appear to be referenced at all. All the tables in this screenshot are referenced in the spark routine except for the "Spark low load maximum", "Spark Idle In Gear ECT" and "Spark Idle In Park/Neutral". I believe this is why they are all set to 63 from the factory.



    I may be wrong and they are accessed indirectly somehow but I can't seem to see where.

    It appears we are missing another table for cold start idle timing, you can modify cold start when you aren't at idle but there is another routine that controls the idle timing when cold. I tried to find it but no such luck yet.
    Rolls, lets take this offline but like a whole heap of scalars and tables "Spark low load maximum" is referenced indirectly There is approximately 320 of these indirectly referenced tables as well as things like the TMAP and Boost Slope and Offsets

  18. #18
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    Darryl why take it off line? It's all useful info.

    Roll's can confirm the idle spark tables directory influence idle timing. Is your spark source idle control when idling? Perhaps you have an issue with the car preventing it from use idle control as spark source?

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    Luke, because I am not sure HP Tuners will want me discussing on an open forum how to track these down. Especially the scripting of it and how once you have done one then you can automate the entire process for the remaining calibrations

    I will ask if you wish.

  20. #20
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    Maybe they would like that? Might speed up the process? They are hiring by the way.
    04 Velocity MKII M6 & 06 BF F6 555 ZF6