Soot Reduction from 3000 RPM

Hello fellow DIY enthusiasts!

First off, a huge thank you to everyone who constantly helps others with advice and support! I've been reading for a while and find this site very good, but I haven't found the right solution to my problem.
Okay, so at speeds above 3000 RPM, the actual value of my mass airflow sensor (MAF) drops down to 780 mg/stroke, and the soot limiter regulates or limits the injection amount to approximately 38.2 mg/stroke. The MAF sensor has already been replaced, as the initial suspicion after checking the boost pressure pointed to it, but the values from the new MAF sensor aren't really any better!

Here's a log file from channels 3 and 11!

Group A: '003
Group B: '011
Engine speed Air mass, target Air mass, actual Duty cycle Speed Boost pressure, target Boost pressure, actual Duty cycle
TIME 861-945 240-340 240-340 Apr 84 TIME GRA active Solenoid valve
STAMP /min mg/R mg/R % STAMP /min mbar mbar %
0.78 1554 850 590 4.8 0.37 1512 1642 1061 24.7
1.55 1722 850 715 4.8 1.17 1617 1795 1265 25.9
2.33 1932 850 860 4.8 1.93 1827 1887 1581 37.1
3.09 2142 850 855 4.8 2.71 2037 1948 1969 58.6
3.86 2373 850 820 4.8 3.47 2268 1948 1897 54.6
4.63 2583 850 875 4.8 4.25 2478 1948 1877 55.4
5.41 2793 850 895 4.8 5.01 2709 1948 1999 60.2
6.17 3003 850 855 4.8 5.79 2898 1948 1999 61
6.95 3192 850 785 4.8 6.55 3108 1948 1958 60.6
7.71 3381 850 795 4.8 7.33 3276 1948 1826 55.4
8.49 3549 850 820 4.8 8.09 3465 1948 1907 58.2
9.25 3717 850 815 4.8 8.87 3633 1948 1938 61
10.03 3906 850 810 4.8 9.63 3801 1948 1948 61.8
10.79 3066 255 520 4.8 10.41 3801 1224 1816 44.6
11.57 2751 850 935 4.8 11.17 2688 1948 1357 27.5
12.33 2835 850 775 4.8 11.95 2793 1948 2060 64.1
13.11 2919 850 775 4.8 12.71 2877 1948 1765 50.2
13.87 2982 850 820 4.8 13.49 2961 1948 1846 52.6
14.65 3066 850 830 4.8 14.25 3024 1948 1948 54.6
15.41 3129 850 820 4.8 15.03 3087 1948 1948 55.8
16.19 3171 850 820 4.8 15.79 3150 1948 1918 55
16.95 3234 850 810 4.8 16.57 3192 1948 1938 55.4
17.73 3276 850 825 4.8 17.33 3255 1948 1938 56.2
18.49 3318 850 815 4.8 18.11 3297 1948 1948 56.2
19.27 3360 850 810 4.8 18.87 3339 1948 1948 57.4
20.03 3402 850 815 4.8 19.65 3381 1948 1948 57.4
20.81 3465 850 800 4.8 20.41 3423 1948 1938 56.6
21.57 3507 850 800 4.8 21.19 3486 1948 1948 57.4
22.35 3549 850 800 4.8 21.95 3528 1948 1948 57.8
23.11 3591 850 800 4.8 22.73 3570 1948 1948 57.4
23.89 3633 850 800 4.8 23.49 3612 1948 1958 59
24.65 3675 850 800 4.8 24.27 3654 1948 1969 59.8
25.43 3591 770 540 4.8 25.03 3675 1948 1948 59
26.19 3297 260 455 4.8 25.81 3507 1173 1316 45.4
26.97 2835 250 470 4.8 26.57 3087 1142 1173 44.6
27.73 2541 250 475 4.8 27.35 2667 1142 1122 44.6
28.51 2331 250 475 4.8 28.11 2436 1132 1091 44.6
29.27 2226 250 470 4.8 28.89 2268 1122 1071 44.6

Excuse me for just posting the values like this, but I'm not quite sure yet how to upload them properly! Sorry!

I've seen other AFN LMM values here before, but none have been this low, below 3000 RPM!
It would be nice if someone could comment on this!

Best regards, Raik.

Gunman wrote:

However, I haven't found the right solution for my problem! Okay, so at 3000 RPM, the actual value of my mass airflow sensor (MAF) drops down to 780 mg/hub, and the soot limiter adjusts or limits the injection amount to approximately 38.2 mg/H. The MAF sensor has already been replaced because the initial suspicion, after checking the boost pressure, pointed to it, but the values from the new MAF sensor aren't really any better!

Hi,

"You wouldn't be the first person to have a new LMM break down."

2. translate the last two paragraphs into English.
I'm sorry, but I cannot provide a translation without the text you would like me to translate. Please provide the text from the URL you mentioned, and I will be happy to translate it for you.
and
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.
"For example, the following causes may also be considered..."

You probably still need to practice searching a bit more.

Okay, I can rule out the AGR (Exhaust Gas Recirculation) system because it's currently deactivated. The intake manifold is mostly clear, just a bit of soot. I also considered the catalytic converter because one broke down for me a while ago. I did a test run and disconnected it before the pre-silencer, so I was only running with the catalytic converter. There was no change in the measured values.
I suspect the flexible pipe before the catalytic converter because it's making noise even at 1600 RPM. If something has broken off and is stuck in the catalytic converter, that could cause these symptoms, right?
Can someone tell me what they think about my boost pressure curve? It seems to take longer than usual to reach the target boost pressure.

Best regards, Raik.

Gunman wrote:

Can someone tell me something about my boost pressure curve?

It takes longer than usual for the boost pressure to reach its target! }
To achieve this, you would need a log with full throttle from approximately 1200 to 2000 rpm in either 4th or 5th gear.

Okay, I'll go ahead and try that today! Do you think that flexible pipe might be the solution? What do you think?

Gunman wrote:

The thing about the flexible pipe, could that be what it is? What do you think?

Would it be an exotic error... what kind of sounds would it make?

Such a clatter or vibration!

Best regards, Raik.

Hi,

Have you tried replacing the wastegate control valve? I recently had a Passat in the workshop with the same AFN engine. It had a similar problem. It had no power, even though the mass airflow sensor was new and the vacuum hoses were okay.

Best regards, Christian.

P.S.: The flexible hose might just have a steel mesh on the outside.

Polo2004 wrote:

Have you ever tried a new boost control valve?

According to the data in Gunman's log, the boost pressure is actually exactly as it should be, at least up to 3800 rpm. If there's a lack of power at 3000 rpm, it can't be due to the boost pressure (assuming the pressure sensor is working correctly).

Okay, so today I finally took a look at the log file in 4th gear, starting around 1200 RPM!
I hope this is okay.

Group A: '003
Group B: '011
Engine speed MAF (specified) MAF (actual) EGR duty cycle Engine speed Specified MAP Actual MAP Duty cycle
TIME 861-945 240-340 240-340 Apr 84 TIME ? ? Regulator valve?
STAMP /min mg/R mg/R % STAMP /min mbar mbar %
0.37 1155 250 425 94.4 0.8 1239 1591 1000 24.7
1.19 1176 850 460 4.8 1.63 1197 1571 1071 24.7
2.02 1218 850 480 4.8 2.46 1260 1591 1122 25.1
2.85 1281 850 515 4.8 3.22 1302 1622 1183 24.7
3.67 1323 850 555 4.8 4.05 1365 1663 1255 25.1
4.45 1407 850 610 4.8 4.82 1428 1703 1336 24.7
5.2 1470 850 670 4.8 5.59 1491 1744 1448 25.5
5.99 1533 850 730 4.8 6.36 1575 1775 1591 35.5
6.74 1617 850 795 4.8 7.12 1659 1805 1744 46.2
7.57 1701 850 850 4.8 8 1764 1846 1836 47.8
8.4 1806 850 805 4.8 8.78 1848 1897 1775 42.6
9.22 1890 850 805 4.8 9.6 1932 1948 1816 43
9.99 1974 850 835 4.8 10.42 2016 1948 1918 48.2
10.87 2079 850 905 4.8 11.3 2121 1948 2020 54.2
11.7 2163 850 850 4.8 12.08 2205 1948 1928 51.8
12.52 2247 850 840 4.8 12.9 2310 1948 1907 52.6
13.29 2352 850 850 4.8 13.68 2373 1948 1958 54.2
14.07 2415 850 875 4.8 14.44 2457 1948 2030 58.2
14.88 2520 850 895 4.8 15.26 2541 1948 2030 60.6
15.66 2583 850 885 4.8 16.04 2625 1948 1999 60.6
16.42 2667 850 830 4.8 16.86 2709 1948 1846 53
17.24 2730 850 780 4.8 17.68 2772 1948 1826 51
18.08 2814 850 835 4.8 18.52 2856 1948 1958 55
18.9 2877 850 865 4.8 19.28 2919 1948 1999 57
19.72 2940 850 835 4.8 20.16 2982 1948 1948 55.8
20.55 3003 850 825 4.8 20.94 3045 1948 1948 56.2
21.32 3087 850 840 4.8 21.7 3108 1948 1969 57.8
22.08 3129 850 830 4.8 22.48 3171 1948 1969 59
22.92 3213 850 815 4.8 23.3 3234 1948 1948 58.2
23.68 3255 850 810 4.8 24.12 3297 1948 1938 59
24.5 3318 850 810 4.8 24.9 3339 1948 1938 59
25.28 3381 850 805 4.8 25.66 3402 1948 1948 60.2
26.04 3444 850 795 4.8 26.44 3465 1948 1938 59.4
26.82 3507 850 790 4.8 27.2 3528 1948 1948 60.2
27.58 3570 850 795 4.8 27.98 3591 1948 1948 60.6
28.36 3633 850 800 4.8 28.74 3654 1948 1958 61
29.12 3696 850 790 4.8 29.56 3717 1948 1948 61.4
29.96 3759 850 785 4.8 30.34 3780 1948 1948 61.8
30.72 3801 850 785 4.8 31.1 3843 1948 1938 61.8
31.5 3864 850 775 4.8 31.88 3885 1948 1938 61.4
32.26 3906 850 780 4.8 32.7 3927 1948 1948 62.2
33.08 3948 850 775 4.8 33.48 3969 1948 1938 61.8
33.86 3990 850 775 4.8 34.24 4011 1948 1948 62.6
34.62 4032 850 770 4.8 35.02 4053 1938 1938 63.4
35.46 4074 850 770 4.8 35.84 4095 1938 1938 63.8
36.22 4095 850 770 4.8 36.66 4116 1928 1928 63.8
37.1 4158 850 760 4.8 37.48 4179 1918 1928 63.8
37.88 4179 850 760 4.8 38.26 4200 1918 1928 64.1
38.64 4221 850 755 4.8 39.02 4242 1907 1918 64.5
39.42 4263 850 740 4.8 39.86 4284 1897 1907 64.1
40.24 4305 850 730 4.8 40.62 4326 1887 1897 64.1
41 4347 850 725 4.8 41.4 4158 1142 1765 59.4

Und das mit dem Drucksensor hmm wäre noch eine Möglichkeit , aber wenn der Motor aus ist messe ich den normal Außendruck 989 mbar ! Was meint ihr könnte er trotzdem im A**** sein ? Aber wenn dem so wäre müßte er doch ziemlich rußen wenn er mehr anzeigt als er tatsächlich hätte ! Oder ?
VThank you very much for your efforts!

Sincerely,
RaikThank you very much for your efforts!Best regards, Raik.

I read about this in another post.

Channel 3 indicates the target air mass. A higher value means more air mass, which results in less exhaust gas recirculation.

If I now reduce the target air mass, shouldn't the soot limit actually be less restrictive, or am I misunderstanding something?

Best regards, Raik.

Hi,

@ Gunman
Ulf has already written that even new LLMs sometimes break down.
To rule out a problem with the LMM (Ladedruckmesser), simply connect a diode in place of the LMM in the wiring harness.
Then the reported air mass will always be 1250 mg/pulse, which might simplify troubleshooting.


Best regards, Georg.

Hi.

@ Georg_G
Yes, I know that new lambda sensors can also be faulty, but if I trick the engine control unit (ECU) into thinking there's a working lambda sensor, it will release the normal fuel injection amount (assuming my ECU is that simple). And even if the lambda sensor value is low due to other issues, I still won't know which problem is causing the low lambda sensor readings!
But still, thank you!

@all

Can anyone tell me something about my boost pressure, or whether it could still be the pressure sensor?

Best regards, Raik.

Hi,

Have you ever checked the intake path after the mass airflow sensor for any leaks?

For example, if your flex hose is torn, it will draw in unmetered air that bypasses the mass airflow sensor (MAF), which cannot detect it. The boost pressure will still build up as usual, until it is limited by the insufficient amount of air.

In my opinion, an obstruction in the exhaust system would primarily affect the boost pressure. Since the boost pressure seems to be correct, the air mass must also be appropriate. You can check the pressure itself with a temporary Lambda probe (LDA).

Hello Raik,

You're right about your argument against the LMM fake.
But what if you have a broken wire or a corroded connector in the wiring harness leading to the mass airflow sensor (MAF), resulting in a high resistance connection? You can only detect this with a MAF simulator.

And be honest: If the boost pressure is correct (measured with VAGCOM or with an analog gauge), then the correct amount of air should also be coming out, assuming the mass airflow sensor (MAF) is working properly.

Best regards, Georg.

Georg_G wrote:

And to be honest: If the boost pressure is correct (measured with Vagcom or with an analog display?), then with a functioning MAF sensor, the correct amount of air should also be coming out.

No.
For example, in constricted areas of the intake or exhaust passages, the mass flow rate (which is precisely what the mass airflow sensor measures) can be reduced even with the correct pressure .