Adjust synchronization angle

Hello,
I have a question regarding the PD-NW setting:

Assuming the ZR was properly installed and tensioned, but the engine still doesn't run correctly because the synchronization angle is incorrect, couldn't you simply loosen the 3 NW screws and then adjust the central screw slightly?

I have already read the technical article.

What _exactly_ do you mean by "the synchronization angle is incorrect"?

By that, I mean the value in the MWB 4, which should be within a tolerance range depending on the engine type (e.g., -3° to +3°).

... and where is he with you?

If the ZR is set to the limit of 3°, you should be careful that it is being adjusted in the correct direction.

Is the ZR (zero reference) incorrectly set, which means that the long holes are already in the desired adjustment direction, you may need to re-set the ZR.

Definitely proceed cautiously, and if necessary, adjust several times. I don't know exactly what the degree of offset between the piston and valves needs to be for contact with the opposing side.

Hello

I recently wrote a "how-to" guide on how to adjust the synchronization angle retroactively in another forum:

It is advantageous to measure when the engine is at its full operating temperature and idling in neutral.
It's best to make notes of the values.
First, turn off the engine, then remove the upper part of the timing belt cover.
You don't need to loosen the strap to adjust the twist angle; instead, you leave the strap and the tensioning roller as they are.
Often, it is helpful to use a marker to make a marking around the 3 screw heads, in order to better assess the adjustment.
Loosen the 3 screws on the camshaft pulley, while holding the central screw in place.
Then, turn the large screw/NW in the middle, in the direction indicated by VCDS (VCDS always shows you where you need to go, not where you are).
When the crank angle is advanced (the crankshaft leads), rotate counterclockwise.
For positive values (the crankshaft is lagging), in the clockwise direction.
You only need to turn it very slightly, because 1° is not much, about 0.5mm of movement on the screws.
Above 4° it becomes critical to closely monitor the gap between the valves and the piston.
The 3 M8 SW13 screws are then tightened again to 25Nm.
Then restart the motor and check MWB 4 again with VDCS.
Repeat the procedure as many times as necessary until it works.

Don't despair, you'll gradually get a sense of how much you need to adjust.
0.5° is fine, or even zero, depending on your ambition or preference


Hope this helps some writers.

Greetings, Mpire

Hi,

Quote:

You don't need to loosen the belt to adjust the twist angle, but instead, you leave the belt and the tensioning roller as they are.

Of course, how else? The belt adjustment is only necessary when it needs to be shifted by one tooth.
hg
Herbert