TDI ALH: Can't Adjust Injection Timing with VCDS?

Hello, I urgently need help with a Golf 4 TDI engine, engine code: ALH. I can't adjust or change the injection timing using VCDS. After repeated starting and driving, I can lock the timing belt, meaning the crankshaft is at TDC, the camshaft is fixed with a ruler, the flywheel mark is also centered in the transmission opening, and the ESP is locked with a pin. All the timing marks always align correctly!

When I adjust the ESP sensor with the three screws towards the windshield, the engine fails to start or starts very poorly (tried multiple times). In VCDS, in the "Measurement Blocks" (MB) or the "TDI Timing Checker," the value is adjusted down from 77 degrees to 38 degrees, and it stays at that value – why? When I turn the ESP sensor towards the radiator, the engine always starts immediately, but it runs roughly. In VCDS, the value immediately drops back to 38 degrees. If I position the sensor roughly in the middle, the engine starts immediately and runs smoothly. In VCDS, the value drops back to 38 degrees and remains there. Why is it always 38 degrees?

"Two ESPs (Electrical Submersible Pumps) are installed and fully functional; all markings align perfectly when connecting them. There are no errors in the field system (FS). Why do I always get a reading of 38 degrees? And for MSWB-4, the desired start-up value is 2.9 bar (relative to atmospheric pressure), but the actual value is 0.0 bar. I'm holding the gas at approximately 1050 RPM. The desired value is 3.5 bar, but the actual value is 13.6 bar! The duty cycle is consistently at 44.6%. If I rotate the sensor, regardless of the direction, shouldn't the values change or at least be different?"

I'm really at my wit's end. How should I proceed? What can I check? What are these values related to?

Please help me, thank you.

Hi,

Quote:

If I turn the wheel, no matter which direction I turn it now, the values should change or always be different!

No. You haven't understood what a regulation does. You will only notice significant changes in the actual value when it reaches the respective adjustment limits. The target value always remains the same, because the engine control unit doesn't care what you adjust; it simply expects a correct setting. And that's exactly what the TDI-Timing-Checker is for: to provide a correct mechanical baseline adjustment.

Here's how it works:
Ich kann den Inhalt dieser URL nicht abrufen, da ich keinen Zugriff auf das Internet habe. Bitte gib mir den Text, den du übersetzt haben möchtest.

Best regards, Rainer.

But if I'm misinterpreting something, shouldn't I see it reflected in the TDI timing check? Or shouldn't the value change? And why does the value always stay at 38 degrees, no matter how much I turn the wheel?

Unfortunately, there is no specialized article available here on regulations and control; instead, I found the following information online:
https://www.ingenieurkurse.de/regelungstechnik/einfuehrung-in-die-regelungstechnik/regelung/definition-der-regelung.html

dieselschrauber wrote:

Unfortunately, there is no specialized article here regarding regulation and control...

Wasn't that a topic in "Hähnlein's Superthread" ?

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.

... Back then, we were also groping around in the dark until the result finally came out to be:
First, adjust the pump mechanically, and then check it using VCDS.

But I've already reset the engine and ESP to their default settings repeatedly, because you said the control unit expects the correct default settings! So, how should I proceed, or what should I change?

Are you really in the default settings mode of the MWB 0? Is VCDS also not a pirated copy that doesn't work properly?

The regulation is not currently in effect; please refer to the link to the technical article for more information.

Best regards, Rainer.

My VDCS is Org., what should I do next, or what can I check?

Who says that the values in the timing checker or in the MWB 0 are in degrees? These are raw values!
You haven't understood the measurement principle.
hg
Herbert.


PS: The setting shown in the first picture would have been perfectly fine (except for the engine being too cold), provided that the basic setting mode was used and the curve appropriate for the vehicle's year of manufacture was selected.

Okay, sorry, so I guess they're just raw values, but even so, I should be getting a different value after rotating the pump wheel! Is it possible to adjust the injection timing using VCDS? I think I saw a friend do it once; he entered some kind of login code and changed values, or something like that. How does that work?

You can essentially only check the start of injection with VCDS. In the ALH engine, the adjustment is made by rotating the loosened pump rotor (do not loosen the central screw!) against the pump.
"As you did in the first setup described above, please provide a picture of the timing now, with the correct temperature, and a picture of the main control unit (MWB) 0 after switching from the basic settings mode (without pressing the accelerator or opening any other MWB!)."

mani38 wrote:

I think I saw it happen with a friend who entered a login code somewhere and changed some values, or something like that.

When you log in, you can easily adjust the injection volume (always in the opposite direction), but you can only adjust the start of injection by rotating the loosened pump gear.

Regards,

Sebastian.

Aha, und wie geht das ? Thank you.

Possibly, I can test again tomorrow, and I will let you know the results.