Random misfire

Has check engine light on with P0300 random multiple misfire code no cylinder specific codes have checked cap rotor wires plugs changed coil holds steady 20 lbs vacuum, compression is in acceptable range. Had it in for diagnostics they could not figure it out. Only notice at idle runs fine otherwise. New fuel pump. When it goes into closed loop the LTFT goes negative on both banks but more on bank two. Upstream O2 sensors switching as they should downstream reads 8 8 1/2 indicating rich condition as the LTFT does. Fuel pressure at 58 lbs. One thing I still question when checking whats happening with scan tool computer has timing at 24 - 25 degrees at idle this seems to advanced to me. Any thoughts?