LSJ timing spikes while idling (running ve only)

[jrsmith]

I currently have my car set up for ve tuning, maf, stft & ltft are off. When the vehicle is idling i'm noticing cylinder airmass between 12 & 16 g/s, and the rpms are between 750 & 900.
As you can see below from my tune, spark table for that range is 16-19.
spark.PNG

However, when the vehicle is idling, i'm seeing swings in timing from 20 to 1 degree. The midpoint seems to be around 10 degrees and then the timing will start to increase until it almost reaches 20, then I notice the tps increases a little and that seems to bring the timing back down to around 1 degree of timing, then it repeats again. My AEM AFR is reading around 13 when timing is at 20, then decreases to 14.8 when around 1-3 degrees timing.

I've adjusted the main VE table to lean it out a bit.

I'm wondering why the timing is changing when it is supposedly "set" at 16-19. is the ecu taking control of the timing due to it running too rich?



2017-10-26.hpt2017-10-26 746pm.hpl

[cobaltssoverbooster]

thats not the idle ignition table.

this one is.....
lsj idle.png

further more the idle overspeed and coast down are capable of adding or removing 13* of ignition fairly quickly.
best you make the main spark idle range match that of the main idle ignition table. also these engines do benefit from an increased idle advance value so play around with that some and you should get less swings.