Hi Tom,

You should be able to set Low RPM back to 34K thru the GDT's "Adjust Idle Revs" function (refer to Operating Manual page 17).

"Now my idle is back up to about 39k" Is this the reading while the engine is running? To set lower Idle RPM while the engine is running, please refer to manual page 21 - "Calibrating MIN and MAX rpm - Adjust Idle Speed"

Please let me know if the above procedures help.

Regards,
Kraivuth S.