1Z Engine Slows Down Before Restart

I think we've discussed this topic before: The 1Z engine in a Passat is slowing down gradually while driving on the highway, eventually coming to a stop.
80 km/h. After turning off the engine and restarting, everything was fine again, until...
It happened again, 5 minutes later.
The error code indicates 575, which means a turbocharger pressure problem: the hoses or the magnetic valve for turbocharger pressure regulation are defective. Everything is now new, but the problem persists. Due to the vehicle's year of manufacture (1994), the turbocharger pressure sensor is not yet located in the air intake pipe, but is connected to the engine control unit via a hose.
Does anyone know about this?
Hinweis: hatte das gleiche schon mal bei einem neueren Motor, wo der Ladedruckfühler einfach getauscht wurde. Der war mit dem Temperaturfühler kombiniert im Luftrohr. Aabout here...?

Best regards, Lanz.

Hi Lanz.

"In my opinion, this is another typical case that led me to the realization that it's ridiculous to offer TDIs without (a mechanical) LDA – or that every interested driver should retrofit one."

Without at least a temporary LDA (Lambda Direct Injection), you probably won't get very far, because the pressure sensor itself might be broken or its solder joints might have come loose... or the charger itself might be faulty (the wastegate might be stuck).

Deleted upon request.

Hi Gustav,

I think Ulf probably means "LadeDruckAnzeige" when he uses the abbreviation LDA.

Best regards,

Jan, who also hasn't had the chance to put something like that together yet.

Jan6K wrote:

I think Ulf probably means "LadeDruckAnzeige" when he says LDA.

Bingo

I didn't know that the term is used with a different meaning in the hardcore "anti-" diesel technology community .

This abbreviation for the advertisement is quite common here.

Deleted upon request.

diesel.gustav wrote:

The vehicle owner contacted the forum. I advised him to simply measure the output signal of the boost pressure sensor with a multimeter while the engine is not running, and to post the result. The target value for the signal of this sensor, at atmospheric pressure, is approximately 2.3 V. However, only approximately 1.8 V was measured. ...

Hi Gustav,

However, a pneumatic LDA can be extremely helpful as a control check against electronic systems.
For example, your "customer" could have also obtained a lower pressure reading during a diagnostic test using VAGCOM compared to the LDA reading. This discrepancy, with a little thought, could have led to the solution.

In this case, this thread also smells like a potential electronics problem. And that's where a cross-check using a simple and reliable LDA would be helpful .

Deleted upon request.

diesel.gustav wrote:

With my simple voltage measurement at the boost pressure sensor, which I always do first in such cases, I would have found the error in a maximum of 10 minutes.

Hello Gustav.

If you have target values for the sensor output voltages, then it is, of course, very easy.

But such target values are not necessarily available everywhere .
...and then, comparing the sensor value displayed in plain text (e.g., using VAGCOM) with a "redundant" display is often the only way to check its accuracy.