Timing question

[probedude]

The reason for disconnecting the TPS is to tell the ECU to NOT mess around
with either the idle or timing settings so you can adjust them without
getting confused.

I know on other non-Nissan cars I've owned, timing at idle was advanced by
the computer to promote a smoother idle.  So on those cars if you set the
idle to the factory value without telling the computer to not mess with it,
you would actually end up retarding the timing.

I haven't bothered trying to set the timing on any of my Nissans without
doing it the proper way so I don't know if the above would be true for them.