e38 6.2L conversion from 5.3L timing bounce in park only not drive XXX

[huttner1]

Hi all Dayton MN here,, needing help on tuning question this client installed a 6.2L and it had cam upgrade, at idle the timing bounces like a big cam but in gear it idles normal no bounce.... where is there a setting in the software to smoothe this out at idle in park/ neutral ?? or does any one have a 6.2L file i can compair with? thank you in advance

[swingtan]

Doest the engine have an idle hunt when in neutral?

I'd have guessed tha tthe neutral idle air flow was too low, causing a hunt that then results in excessive spark timing corrections. Putting it in gear adds more air flow and the increased engine load tends to calm down the idle.

Post a log of the issue making sure you include airflow, RPM, ETCTPS and spark. Fuel trims would also be good.

Simon