Liberty GT 2008

[revzone]

Hi,

Tuning a Liberty GT 2008 model , 2.5L turbo with 268EX and 277IN Cams

Having problem with making the idle prefect

SOMETIMES I will get a negative timing ( example -20 )
and the engine idle become rough
But it doesn't happen every time at idle
I noticed it happens every time when the car is on boost and jump off the throttle
at that time, If i give it a small rev
the idle is normal again

Any idea what this could be?
look though the whole map, can't find any parameter I can fix this issue

Thank you very much