AUFLÖSUNG auf S. 2 - TDI AFN - Mengensteller oberer Anschlag | Posts 16+

Hello,

Quote:

Rainer, you wrote that the error "quantity adjuster, upper limit" can also be caused by this, and I suspect that the quantity adjuster has been shifted axially towards the HD part. Would that be plausible?

I only remember that the error sometimes occurred due to misadjusted or loose quantity setting mechanisms... I've forgotten whether it was the upper or lower limit that was affected.

Best regards, Rainer.

Hi,
The question is, what kind of pressure does the pressure sensor read when the ESP is assembled?
On one hand, the control ring on the distributor spool has a mechanically limited travel range. On the other hand, the torque motor in the control unit also has its minimum/maximum limit.
My assumption is that the self-diagnosis of the injection system refers to the latter. Ultimately, you can only figure that out by taking a closer look at the pump itself.
The usability of the MSW setting can be somewhat assessed by looking at the values of the sensor for RSW during ignition (MWB #1, value 3) and for EM (MWB #1, value 2) at idle with a warm engine.
For the RSW voltage, it's 0.7V to 0.74V, and for the EM, approximately 5 mg per cycle. Assuming the motor doesn't have any other issues. What happens to the RPM if you initially reach about 2500 RPM while idling, and then release the throttle? Does it immediately drop to the target value (approximately 860 rpm), or does it go through an intermediate stage?
Based on your description, I would rule out a severely misaligned timing belt, as that would likely cause the engine to have starting problems or make a sawing noise.
hg
Herbert.

Thank you both! I don't have the car here right now, but the RPM definitely drops with the swing arm, as you can see in the intermediate stage. It's wave-like, if you want to describe it that way.

It's just a very slight vibration, so not a strong jolt in the car body, but it's definitely noticeable by the sound.

I need to check the MWB.

Hi,
This suggests that the mixture is a bit too rich, and consequently, the displayed engine temperature (EM) in VCDS is likely too low. Let's wait and see what the numbers are.
hg
Herbert.

Herbert wrote:

Hi, This suggests a slightly too rich setting, and consequently, the AFR (Air-Fuel Ratio) displayed in VCDS would be somewhat too low.

That's also my recollection of the AFN.

Quote:

Let's wait and see what the numbers are.

I would do the following: Unscrew the pump cover again, connect VCDS, access module MWB1, manually push the RWG to its stops and observe the voltage in MWB 1 while doing so.

If the voltage levels are within the specified tolerance ranges for both, then everything is okay.

If they are located very close to one of the boundaries, even the mounted pump cover can push them into the error range (or the usual temperature drifts caused by weather and engine operation) -> readjust the RWG (presumably a control unit or sensor).
The fixed part represents the spread between the minimum and maximum values. The striking voltage determines, and twisting the arm on its axis shifts this spread up or down on the tension scale... clear?

Okay, so by combining a measurement ring and a reference ring, one shifts an entire spread within the measurement field/measurement ring, which is then voltage-interpreted by the control system?

The starter motor engages the starter pinion when the ignition is turned on. Are you sure that I will be able to manually operate the RWG without any, even slight, magnetic counterforce from the coil?

Could you please provide the reference values for MIN and MAX again? Thank you! I will be able to check that next week.

Does a misaligned setting indicate that the quantity adjuster has shifted towards the high-definition (HD) side, or is the axial displacement unrelated to this?

I'm slowly getting confused, sorry...

EDIT: It seems it might be so...

QUOTE FROM ULI:

The displayed amount is the opposite of the injected amount, quote:

"- The displayed fuel injection quantity is too high: The actual fuel injection quantity is too low; the adjustment mechanism on the fuel injection pump needs to be moved towards the high-pressure side."
Sure, here is the translation of the text from German to English:

"Source: /viewtopic.php?t=5517"

This means that your initial fuel setting is too low after the adjustment, which is causing the engine to start poorly. The solution is to readjust it to the original value or experiment until you find the right amount that provides verschandeln combustion, smooth operation, and quick starting. I only experience rough running with the AFN system below 1800 RPM and with high fuel percentages. The injectors have 0.216mm nozzle openings. Perhaps the problem lies elsewhere. Did the NHG perhaps get hit with something during the jet swap?

Hi,
We discussed the reference values earlier (if 1Z and AFN are comparable). Please note that the displayed values can be slightly different with the lid on and with the lid off, as the lid affects the magnetic field. The values with the lid on are the ones that should be considered. You can, however, determine the voltage difference (approximately 0.2 V).
"If you're getting a warm idle reading of 4mg, that's not really bad. You can initially improve this through adaptation on channel 1 (see the technical article). After the MSW cleaning, I also adjusted it until I reached 5mg +/- 0.5. However, it probably doesn't depend solely on the value itself, but on the entire configuration." That's why I'm asking about the minimum/maximum values for the RSW voltage.
I'm not sure about the magnetic counter-force when twisting with the ignition on. It's possible that the injection control system is trying to set the value to 0.
hg
Herbert.

Deus Violentia wrote:

Ah, so, by combining the measuring and reference ring, one shifts an entire spread within the measuring field/measuring ring, which is then voltage-interpreted by the control system?

You probably mean something close to that.
If the difference between the displayed values is so small or so large that at least one voltage must always be outside the minimum and maximum tolerances, then the reference ring must be readjusted in any case.
If the difference between the displayed readings corresponds to the distance between the setpoint fields, then a calibration of the measuring ring may be sufficient.

Quote:

The starter motor, when in the "ignition on" position, engages the starter pinion. Are you sure that I can manually operate the RWG

without any, even a small, magnetic counterforce from the coil? It's possible, but I've never tried it that way.
As long as you can overcome the opposing force without applying excessive force that could damage the material, I don't see any problems, except perhaps for a potential... Error entry.
Based on the circuit design, I suspect that the magnet can only open the MSW (Micro Switch), while the spring is responsible for closing it.
An active magnetic attraction force towards zero would, in my opinion, require a polarity reversal of the magnetic shielding wire, but that is fixed to 12V with 1 pole, if I recall correctly.

I once took a close-up photo of the VP37, focusing on the ring joint of the inlet pipe. You can clearly see the displacement of the flow control valve, I think. The scratch mark is also not from me, and I only noticed it yesterday .
I was unable to observe such a significant shift towards the high-definition portion in two other vehicles equipped with VP37. The VAG-COM values are not yet available...

Solution:

Despite the clear visual inspection, the area was filled with debris.
After a complete renovation, the problem is gone.

KW stub and ZR wheel worn out, but only visible after disassembly .
Get it planned and a new timing belt wheel installed.

It seems things are going well now, THANK YOU FOR YOUR HELP!

"Long-term report" - The engine is still running consistently well!