AFN Injection Timing Adaptation (PÖL Adjustment)

Hello!

After modifying my AFN engine to a dual-tank system, I now want to improve combustion at low load by slightly advancing the entire fuel injection map.
I've noticed that the idle sound is noticeably smoother, which, in my opinion, is an effect of the longer ignition delay caused by the PÖL system.
I tried to modify the parameter using adaptation with login 12233 on channel 4, but this resulted in hardly any visible change in the measurement block for the injection time.
I was able to change the value in the adaptation from 32768 to 32800, which resulted in a change from 1.3°BTDC to approximately 1.5°BTDC at idle. No change is detectable at higher RPMs.
VAGcom rejects values higher than 32800.
Can someone please help me with this?

I know that a complete recalibration of the engine's mapping would be ideal, as it would allow for adjustments to the ignition timing based on the load ranges.
'However, I'm looking for a simple solution to improve combustion, so that I don't have to switch back to diesel mode even when driving at 70 km/h on the country road (with a partially or lightly loaded vehicle), and since I already use a two-tank system.'
What value should the map be adjusted to, as a good average, considering 30% diesel operation on short trips, and the remaining 70% operation under ideal conditions (PÖL)?
And what values should I assign to channel 4?
The engine (AFN 81kW, Passat 3B) is running at its standard power output, with no aftermarket chip tuning. The mileage is 140,000 km.

I would be very grateful for your help.

Best regards, Christox.

Hello again.

Okay, today it worked. Without any complaints, VAGcom accepted all the values. I gradually increased the value in block 4 to 32900, which resulted in an injection timing of 2.6° BTDC at idle.
That would be an advance of approximately 1.1 degrees at idle.
Since I have a two-tank system and the engine is always warm when I use PÖL, extreme values are not necessary.
Is this value also acceptable for the engine when running on diesel?
And: Is the injection timing now advanced by exactly 1.1° in every load range, or is it advanced by a certain percentage factor?


Good evening, Christox.

Hello,

Regarding advancing the injection timing, I can only share my experience with my old 1.6L naturally aspirated diesel engine from a Golf. It, of course, had the old mechanical injection pump. I generally advanced the injection timing mechanically by 2.5°. I drove the car with this engine in all configurations without any modifications. I used everything from 100% diesel to 90% rapeseed oil (RME) or 100% rapeseed oil.
The engine ran best with a fuel-oil mixture of 70-90%, operating very smoothly and powerfully. This mixture makes the machine slightly more fuel-efficient and also allows it to rev up more easily.
However, be careful in the summer, as starting the pump earlier can cause a higher temperature. So, avoid running it at full speed during the summer months!
The car had reached a mileage of 290,000 km, but it was still running like a well-oiled machine. However, the bodywork had started to deteriorate.

Bin mir nicht sicher wie der AFN ausgelegt ist. Thermisch aber wesentlich besser bestückt als noch das Urgestein der Diesel VW Motoren. Ich fahre den AFN in zwei Toledos mit ca. 50% PÖL ohne Umbau seit ca. 50000km zusammen auf den beiden Motoren. Der eine Motor hat 220'km der andere 90'km. Beim 90'km Motor hatte ich jetzt öfter den Fehler 01237. Aber zur Zeit ist das wieder weg nachdem ich gründlich alle elektrischen Steckverbinder mit Kontaktöl gepflegt habe. SieThe forum.
Otherwise, the two engines run smoothly in the standard settings.

Hi Hloeckert,

How did you determine an angle of 2.5 degrees for the JP?
Target value: 0.90 mm stroke at top dead center (TDC). Acceptable range: 0.83 .. 0.97 mm.

m;
sometimes up to 70% Poel driving.

Okay, my AFN is working perfectly even at 100%.
However, it's impossible to assess the completeness of the combustion process from the outside without regularly opening the cylinder head. That's why I wanted to counteract deposits by modifying the fuel injection system.

@hloeckert: Did you only shift the start of injection by about 2.5° while the engine was idling?
Mechanically, or alternatively, via adaptation using VAGcom?

Werde ihn bei mir dann wohl um 1,5° frühverlegen. Denke das reicht beim 2-Tank mit 90%Pöl im 2. Tank out.
I usually drive the car at speeds around 140 km/h, and therefore I don't see any risk due to the increased thermal load.
I just want more complete combustion so I don't have to switch to diesel mode on the highway.
Best regards and have a pleasant evening, Christox.

Hello colleagues,

Back in the day, with the older 1.6-liter naturally aspirated diesel engines, there was no VAGCOM available.
I measured the 2.5° from the mechanical starter assist of the engine. In the older models, as with the gasoline engines, there was a "trick." A wire was used to advance the ESP by 2.5°. According to Volkswagen. I measured adjustment values of 1.10mm. During the check at an adjustment value of 0.88m, I was able to confirm the 2.5° on the flywheel. If you forgot about the "trick," it was still effective.
This setting takes effect across the entire speed range because it is mechanically adjusted.
Then I adjusted the setting to between 1.10 and 1.12.
I was forced to do it myself because the friendly technicians at the VAG workshop were unable to properly adjust the injection timing after I had replaced the timing belt.
"My colleagues couldn't figure out how to set up the equipment back then. So, I ended up getting a clock and adapter myself."

OK.

The device is called a "choke" in gasoline engines, and a "cold start accelerator" (KSB) in diesel engines. It doesn't operate over the entire range, but only at idle. It essentially shifts the zero point of the injection timing adjuster.
See BOSCH: Diesel Engine Management.


Thank you for the explanation regarding "measuring the degree of rotation on the flywheel."

m;

christox wrote:

Is the injection timing now being set exactly 1.1° earlier in every load range, or is it being set earlier by a percentage based on a specific factor?

Hi,

We assume that an equal change in magnitude occurs across all operating states controlled by the safety system (provided the pump does not first reach a mechanical limit).