TDI Synchronization Angle: What is it? (Solution)

Hello,

In the PD control data (for 4-cylinder engines), a synchronization angle of -3 to +3 degrees KW is specified everywhere.

What is the significance of this angle (where is it measured), and what happens if it falls outside the specified range?

Hello Ulf!

For my engine (3-cylinder AMF), the specified data indicates a range of -6 to +6° KW, even at idle and full load. "In the relevant documentation, the following is stated regarding exceeding or falling below a threshold:"

-G40 sensor defective (Hall sensor).
-Donor incorrectly positioned or not properly secured.
- Clearance between the donor and... Camshaft sprocket not in good condition.
- Line interruption or short circuit to ground.
---> Check G40!
Hub with drive ring twisted on camshaft, loose.
---> Check the position of the camshaft and crankshaft.

Just thinking off the top of my head:
Could it perhaps be possible to determine, within this 12-week period, exactly how the timing belt was initially installed, or how much it has stretched? That would then mean a synchronization between the KW and NW.
That is to say, if there is an overshooting or undershooting, are the limits of the electronic fuel injection start control being exceeded?


Best regards,
Sure, here is the translation of the text from German to English:

"Dirk"

brezelmann01 wrote:

In the relevant documentation, it states for exceeding/falling below: -G40 defective (Hall sensor NW).

Hi Dirk,

Okay, with that, we've already got the part that we're talking about.

Quote:

Hub with sending wheel on camshaft twisted, loose. ---> Check the position of the camshaft and crankshaft. Just thinking off the top of my head: Could it perhaps be possible to determine, within this 12-week period, exactly how the timing belt was initially installed, or how much it has stretched? That would then mean a synchronization between KW and NW.

I don't think so, because then the RepLeiFa should point out this very obvious possibility .

Based on your information, I'm more inclined to believe that the temporal rhythm of the NW sensor pulses should not deviate by more than +/- 3 (or 6) degrees, or that exceeding the target range compromises the function of the entire hall system (mounting, adjustment, cabling, etc. -> see your posted error list).

Ben1972 wrote:

So, I'll try to explain it, but I only know about it from the R5 TDI engine in the VW T5. In addition to the crankshaft sensor (CKW), there is a camshaft sensor (NW) that serves to facilitate quick starting. There is a marking for each cylinder. When the CKW sensor indicates Top Dead Center (TDC), the Engine Control Unit (ECU) knows which cylinder is currently at TDC based on the information from the NW sensor. This reduces the starting time. If the NW sensor is disconnected, a redundant starting process is initiated. The ECU then injects fuel into the theoretically possible cylinder until it detects the correct cylinder based on the increase in engine speed (DRZ). This process can take some time, which is why the NW sensor is used. The tolerance of +/- 3° CKW or +/- 6° CKW must be maintained. If the NW signal is not detected, the engine will not start. This could be because the sensor wheel on the NW is misaligned, or, in the case of a 4-cylinder engine, the timing belt may have become excessively stretched. This helps to avoid issues like valve attachments, etc. Hi Ben

You can check the synchronization angle in the VCDS measurement blocks; ideally, it should be set to 0°KW.

Ben1972 wrote:

If the NW signal is outside the expected range, the engine will not start, because the sensor wheel on the NW may have become misaligned, or, in the case of the R4 engine, the timing belt may have become excessively stretched. This helps to avoid valve attachments, etc.

Hi Ben,

Thank you for your explanation.
But it seems like avoiding the valve attachment issue isn't quite working out.
If the valve timing is misaligned to such an extent, the starter motor, along with the engine's flywheel, is likely to cause damage (provided that the open valve doesn't already prevent any rotation).

By the way, I also received an email from someone whom I don't recognize as a forum member (so far).
I hope he doesn't mind if I include them here.

Quote:

It's about the synchronization between the camshaft and the crankshaft. So, there are two sensors: engine speed (located at the rear, at the end of the cylinder head) and camshaft speed (Hall sensor). The influence on the synchronization angle is affected by the timing setting (hub of the crankshaft) and the longitudinal torsion of the crankshaft (twisting). The value at idle should be within the specified limits, but it may fluctuate. If the MDZ goes higher, it should be at 0 degrees.

Does anyone know what the abbreviation "ZKD" stands for?

If the synchronization angle actually monitors the relationship between kilowatt (KW) and Newton-meter (NW), then I'm still surprised that the repair manual doesn't mention this possible cause (-> response from brezelmann).

Quote:

Does anyone know what to do with the abbreviation ZKD

You surely mean ZKG's, right?!

I think he's talking about the crankcase...or am I missing the point entirely?

Cu.
Sure, here is the translation of the text from German to English:

"Dirk"

brezelmann01 wrote:

You certainly mean ZKG's, right?! I think he means the cylinder crankcase...or am I missing the forest for the trees?

Hi Dirk,

Yes, of course, ZKG .
The cylinder crankcase might be what you're referring to... but for me, that usually falls under the category of "engine block."

ZKD would then be the cylinder head gasket.

Just to add something here (it might turn into a Q&A session): Based on my experience, I've found that pump-injector engines don't really run well with the VW adjustment method (using a dowel and crankshaft stop). At least, not from the top end. So, during the last adjustment, I switched to this method: use the crankshaft stop at the bottom, and then initially, just roughly adjust the timing at the top end to get it running. Later, I fine-tune the camshaft position based on the engine's performance and top speed, aiming for more power.

I noticed that the pump-injector (ATJ) engine runs very well when the synchronization angle is around 0° (sometimes fluctuating between -0.3° and +0.3°). Any deviation from this range results in power loss, which I also observed after using the VW adjustment method. In the Passat Variant, this leads to a loss of approximately 10 km/h in top speed, and anything above 140 km/h is practically unusable.

Who can understand this, or perhaps has a different perspective, or could even take another measurement?

Quote:

I noticed that the pump-nozzle (ATJ) engine runs very well when the synchronization angle is within a range of 0° (sometimes oscillating between -0.3° and +0.3°)

Based on my observations, this is precisely the value that is achieved with the KW Stop when it is used correctly, i.e., by sliding it in from the rotation, so that the ZR is under tension in the traction direction at that moment.

I personally don't bother with that fiddly process anymore; instead, I manually hold the belt under some tension while adjusting/checking it. Without voltage in the traction transformer of the Z-car, the net power consumption is approximately 1-2 kW, especially during the initial phase.

Mpire wrote:

Hello... ..it took some time, but now it's finally I have read out the extended module work base (MWB) from two vehicles: a 2010 Touareg 3.0 TDI and a 2014 A6 4G 3.0 TDI, both equipped with EDC17. For both, at IDE04... under "Camshaft flank position," the deviation from the crankshaft is X.00°. Attention! - When only the ignition is turned on, the engine always shows 0.00° advance in the engine control unit (ECU). - The deviation can only be displayed when the engine is running. The quality of the crankshaft position (KW) signal and the status test of the crankshaft sensor can also be found in the IDE04 block area. -> It's located quite low down in the list, after all the exhaust aftertreatment values. Greetings Mpire