Hey fabio,
I wanted to pull up as much useful info from the service manual as possible, but there isn't a lot of good stuff.
A few comments: I found mention of the synch procedure you mentioned. It really only applies if you've pulled the distributor out of the engine, and lets you get it back in the engine and aligned. An interesting thing that I noted from reading the manual is that the timing for the engine is NOT controlled by the distributor at all. As long as the distributor is rotated within a certain acceptable range, the PCM controls all timing. The synch procedure will simply make sure the distributor is in an acceptable window. With that said, I'm guessing that if the distributor is NOT in an acceptable window, then it probably wouldn't run well.
Here is what they say about the ignition timing:
CAUTION: Base ignition timing is not adjustable on any engine. Distributors do not have built in centrifugal or vacuum assisted advance. Base ignition timing and timing advance are controlled by the Powertrain Control Module (PCM) Because a conventional timing light can not be used to adjust distributor position after installation, note position of distributor before removal.
Here is the cut and paste from the manual (note DRB is the corporate scan tool of the day, I'm guessing the Snapon tool provides this same information):
CHECKING DISTRIBUTOR POSITION
To verify correct distributor rotational position, the DRB scan tool must be used.
WARNING: WHEN PERFORMING THE FOLLOWING TEST, THE ENGINE WILL BE RUNNING. BE CAREFUL NOT TO STAND IN LINE WITH THE FAN BLADES OR FAN BELT. DO NOT WEAR LOOSE CLOTHING.
1.Connect DRB scan tool to data link connector. The data link connector is located in passenger compartment, below and to left of steering column.
2.Gain access to SET SYNC screen on DRB.
3.Follow directions on DRB screen and start engine. Bring to operating temperature (engine must be in "closed loop" mode)
4.With engine running at idle speed , the words IN RANGE should appear on screen along with 0°. This indicates correct distributor position.
5.If a plus (+) or a minus (-) is displayed next to degree number, and/or the degree displayed is not zero, loosen but do not remove distributor holddown clamp bolt. Rotate distributor until IN RANGE appears on screen. Continue to rotate distributor until achieving as close to 0° as possible. After adjustment, tighten clamp bolt to 22.5 N·m (200 in. lbs.) torque.
The degree scale on SET SYNC screen of DRB is referring to fuel synchronization only. It is not referring to ignition timing. Because of this, do not attempt to adjust ignition timing using this method. Rotating distributor will have no effect on ignition timing. All ignition timing values are controlled by powertrain control module (PCM)
After testing, install air cleaner assembly.