smokeshow

iTrader: (17)

I switched to speed density a couple weeks ago, but have been driving on the old MAF tune because SD refuses to idle without surging or hanging. I was following a procedure on LS2 idle tuning on the HP Tuners forum, only to discover that the final idle airflow minimum table I was modifying was doing nothing. Turns out the throttle body is unresponsive to changes in either the airflow minimum table or the commanded idle in the HPT scanner bi-directional controls. When commanding the idle higher, all it does is increase RPM error which pushes the adaptive idle advance up.

I raise up the idle with the controls in both log files; only the MAF log opens the throttle more. Somehow with the SD tune, the throttle body isn't getting the memo. Why isn't the throttle responding?

smokeshow

iTrader: (17)

Figured it out. It was the "Idle Effective Area Max - Fail" setting. Default is 60, changed to 200. Idle does what its told now. LS2s are a reinvention of the wheel, I swear.