Ladedruckregelgrenze unterschritten | Posts 16+

Okay, the buck is running again. The Lmm was a dead end!
Oh no! It seems like the turbocharger needs some adjustments. While replacing the diode got it running again, it only increased fuel injection. However, the underlying problem remained. The issue couldn't be detected during city or highway driving, but it reappeared regularly on the Autobahn (highway). So, I logged the boost pressure and found that it was too low. Also, the VTG rod wasn't being pulled towards the pressure sensor at idle. It was a clear case of a faulty boost pressure control valve (or 'pressure converter' in VW terminology). After replacing it, everything is working perfectly now.

'Ulf, thanks again for your ideas. Even though it wasn't quite what we needed in the end...'

lappen wrote:

however, the diode only caused an increase in fuel injection volume... then I logged the boost pressure and saw that it was too low.

Were you able to observe any excessive soot formation during that process?

It varied a little from 1900 to 2400 RPM. However, I didn't attach much importance to this, as I know other power drives that react similarly with a diode. The difference is that those have all the components integrated.

Furthermore, the problem must be somewhat older. The consumption has been consistently increasing over time. It was recently almost 8 liters, but now it's back down to below 7 liters.

lappen wrote:

Furthermore, the problem must be somewhat older. The consumption has been consistently increasing over time. It was last almost at 8 liters. Now it is back down to below 7 liters.

It's interesting... when the mass airflow sensor (MAF) is defective (resulting in "too much boost pressure for the actual fuel injection amount"), reports sometimes mention increased fuel consumption – if anything is mentioned about fuel consumption at all.

It seems your car was mostly running in a state of "reduced power," meaning it had less boost pressure than usual, which likely led to increased fuel consumption.

This suggests that the series tuning between quantity and boost pressure may actually be optimized for maximum efficiency...

I find increasing fuel consumption to be normal. To achieve the same driving performance, you have to use your right foot more forcefully and for a longer duration. And, in my opinion, the consequence of this 'gas pedal training' is increased fuel consumption.

Here's another question: Why shouldn't the series trimming be designed for maximum efficiency? Surely, only maximizing efficiency makes real sense... (Okay, we're talking about 'Auh-Weh' here, so a lot of illogical things are just reality.)

lappen wrote:

I find increasing fuel consumption to be normal. To achieve the same driving performance, you also have to use your right foot more and for a longer duration. And the consequence of this "gas pedal training," in my opinion, is increased fuel consumption.

Okay, then let's turn the question around:
If more fuel is injected and, under similar environmental conditions, higher cutting speeds are not achieved, then the engine's efficiency must have decreased.
But why is this happening with both more and less load than usual?

Quote:

Another question: Why shouldn't the series trim be designed for maximum efficiency?

For example, if Mr. Tritt-Ihn has certain ideas about emissions that cannot be achieved at optimal efficiency - such as with a "delayed" injection start in the lower load range.

I find increasing fuel consumption to be normal. To achieve the same driving performance, one must also use their right foot more strongly and for a longer duration. And the consequence of this 'gas pedal training,' in my opinion, is increased fuel consumption.
Okay, then let's turn the question around:
If more fuel is injected and, under similar environmental conditions, higher average speeds are not achieved, then the engine's efficiency must have decreased.
But why?

Bitte gib mir den deutschen Text, den du übersetzt haben möchtest.


Hello,
The more soot produced, the higher the fuel consumption, assuming the same power output.
Best regards,
Günther.

@Ulf

Certainly, the current perception and relationship with certain groups that influence opinions play a role for this 'green' gentleman. This is undoubtedly true, unfortunately. Sadly, these confusions also lead to him consuming more raw materials, which in turn puts a greater strain on the environment than it benefits.