Magnetventil für Spritzbeginnverstellung defekt? | Posts 16+

What happened there? It looks more like excessive use of N2O.


No, no nitrous oxide. The young man just tinkered with things a bit too much. Chip, tuning box, extremely early fuel injection timing, and he also modified his VNT turbocharger...

-Uwe-

Hello,

"My ALH engine isn't running perfectly; I'm having problems with excessive boost pressure. During a test drive, I also logged Group 4, and after reading this thread, I have some doubts about the accuracy of the timing after the timing belt replacement. (Workshops tend to just slap the belt on without making a proper adjustment – they only correct it if something doesn't work out later)."

Okay, here are the values:
First, let's start with idle:
The "should" and "actual" values initially differ significantly and permanently.
Then the actual value is not within the target range (2 to -3) and fluctuates.
By the way: what do +2 and -3 actually mean? (+2 = 2° above OT, and -3 = 3° below OT)?

Time Speed Injection Start Duty Cycle ---
text
Should Actual
0.01 903 0.4 1.8 2.8 0.35
1.14 903 0.4 2.2 2.8 1.55
2.35 903 0.4 2 2.8 2.75
3.55 903 0.4 2.2 2.8 3.95
4.75 903 0.4 2 2.8 5.15
5.94 903 0.4 2.2 2.8 6.35
7.15 903 0.4 2 2.8 7.55
8.35 903 0.4 2.2 2.8 8.75
9.55 903 0.4 2 2.8 9.95
10.75 903 0.4 2.2 2.8 11.15
11.95 1050 0 2 2.8 12.34
13.14 966 0.4 2 2.8 13.54
14.34 1050 0 2.2 2.8 14.74
15.54 1449 -1.3 1.8 2.8 15.94
16.74 1701 -1.3 1.1 2.8 17.14
17.94 1785 -1.3 1.1 2.8 18.34
19.14 1449 4.6 2.9 36.7 19.54
20.34 1785 -0.9 1.5 2.8 20.74
21.55 1932 -1.1 0.7 2.8 21.94
22.75 2121 -0.2 0 3.6 23.14
23.95 2352 0 -0.7 9.2 24.35
25.14 1365 -1.3 2.2 2.8 25.55
26.35 1701 1.5 2.6 39.8 26.74
27.54 1764 -1.3 1.3 2.8 27.94
28.74 1785 -1.3 0.9 2.8 29.14
29.94 1806 -1.3 0.9 2.8 30.34
31.14 1785 -1.3 1.1 2.8 31.54
32.34 1785 -1.3 0.9 2.8 32.74
33.54 1806 -1.3 0.9 2.8 33.94
34.74 1827 -1.3 0.9 2.8 35.14
35.94 1848 -1.3 0.9 2.8 36.34
37.14 1848 -1.3 0.9 2.8 37.54
38.34 1848 -1.3 0.9 2.8 38.74
39.54 1890 0.7 1.1 23.1 39.94
40.74 2100 6.8 3.7 84.9 41.14
41.94 2373 7.9 7.5 74.5 42.34
43.14 2667 9.2 9 81.3 43.54
44.34 2919 2.9 9.7 42.6 44.74
45.54 1701 -1.3 1.3 2.8 45.94
46.74 2142 4.4 4.4 63.4 47.14
47.94 2205 0.9 2 52.2 48.34
49.14 2205 -0.9 -0.7 22.3 49.54

I believe the regulation is already at its limit at 2.8 (I've never seen smaller values).

What makes me suspicious is that at 1700-1800 RPM, the injection timing shifts to a negative value (i.e., it becomes retarded).
The deviation persists even in the mid-range of the engine speed.
The maximum duty cycle of 96.4% is reached at time 211.16.

191.96 903 0.4 2.2 2.8
193.16 903 0.4 2.4 2.8
194.36 903 0.4 2.2 2.8
195.56 903 0.4 2.4 2.8
196.76 903 0.4 2.2 2.8
197.96 1848 5.7 4 64.5
199.16 2772 9.7 8.4 89.3
200.36 2226 -0.9 0 9.6
201.56 2457 8.1 7.7 80.1
202.76 3087 11.2 11.4 83.3
203.96 3696 14.1 14.5 85.3
205.16 2457 8.1 4.2 96.4
206.36 2709 9.5 9.5 78.5
207.56 2961 10.8 10.8 83.3
208.76 3234 11.9 12.1 84.9
209.96 3192 0.2 11 2.8
211.16 2436 7.9 6.6 96.4
212.36 2520 8.4 8.4 78.9
213.56 2625 9 8.8 80.1
214.76 2730 9.7 9.7 79.7
215.96 2835 10.1 10.3 79.3
217.16 2961 10.6 10.8 82.1
218.36 3066 11.2 11 84.1
219.56 3129 11.4 11.4 79.3
220.76 3024 -0.4 10.6 2.8
221.96 2583 6.4 -0.9 62.6

Only in the higher RPM range does a target value sequence begin.

347.94 3339 12.3 12.8 81.7
349.14 3444 13 13.4 84.5
350.34 3549 13.4 13.4 80.5
351.54 3654 13.9 14.1 82.9
352.74 3738 14.3 14.7 81.7
353.94 3843 14.7 15.2 82.9
355.14 2184 -0.9 0 9.6
356.34 2898 -0.2 -0.2 43
357.54 2898 9.2 4 96.4
358.74 2919 10.3 10.8 82.1
359.94 2919 -0.4 0 10.8

If I'm interpreting the numbers correctly, the start-up is happening a bit too early.