Just a few things again to add.
The ECU does not continually adjust ignition timing at idle, and this is when a timing gun is used.
The ECU will adjust the ignition timing according to engine speed and load.
If you guys are convinced that timing is a problem, which i am still very much doubtful, then check the static timing, it is easy enough to do.
Something i think that is worth checking is the knock sensors, if one is loose then the ECU will retard the timing which could cause a problem.