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High idle due to ignition when coming to a stop + on start


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I've had to retune my car after installing a more aggressive cam, the last bit I have to fix up is high rpm after starting the car and when coming to a stop. Usually ~2300rpm after starting the car and ~1350-1480rpm when coming to a stop after driving.

Based on my logs, it appears to be because the ignition is taken from the main ignition map in each scenario and is quite high, between 28-33 degrees of advance which keeps the rpm high and seems to stop idle ignition kicking in. As the vacuum reduces, ignition retards, rpms drop, the idle ignition takes over and idle settles in nicely.

Should I be increasing the idle ignition lockout RPM to capture these scenarios, or is it better to reduce timing on the main ignition map to reduce RPM in these scenarios even though it may affect deceleration when driving?

Or have I got it all wrong and I'm overlooking something obvious?


Tune is attached. I can't figure out how to trim the log into the relevant segments, it's over an hour of driving, so I've added markers and sections for navigation. Here is it zipped (19mb zipped/41mb unzipped): https://lenihans-my.sharepoint.com/:u:/g/personal/ryan_lenihan_com_au/EUfbloVB511Jg0_UQ9sCBYcBaSaZeyPphkI9I41wAhEl6g?e=H8rlpe


230205_469_jaycar run.pclr

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The flare after startup is most likely the start-up step too high.  Try halving that to see if it helps.  

For the rev hang coming to a stop - yes a lot of that should improve if you lift the idle ign RPM lockout up to around 1700, and the speed lockout up to about 20kmh.

I would probably change idle control over to closed loop also, your open loop stuff all looks pretty good so it shouldnt need much extra work to get closed loop working nice.

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Thanks for the quick response Adam. I'll give the changes a crack and adjust as needed. I'm definitely keen to head back to closed loop once this is resolved.

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