AFN Measurement Trip Logs

Hello,

Attached is the log file for my Ibiza AFN.
Starting at 1500 RPM, my air mass is consistently above the target value.
The boost pressure, on the other hand, constantly fluctuates between being too high and too low.

Does this indicate a leak in the turbocharger system?

AGR is defective, although in my opinion, it's insignificant under full load.

Thank you very much!

Hi,

A log about the speed is confusing because adjusting the LD (likely referring to a specific device or setting) is a process that takes time.

m;

Which gear was engaged?

The fluctuation in charging pressure is a result of the control system. This system needs to be calibrated initially.

Okay.
Here about time. Dangers in the fourth [period/chapter/etc.].

However, since I didn't log an alpine drive, but rather a full-throttle acceleration run, the two graphs are very similar.

Hi,

It looks like a typical, slow-swinging pendulum.

However, your car is already going full throttle, isn't it?!

It would also be important to assess the behavior *before* full throttle, so that you can see how the machine reacts to sudden, rapid acceleration.

m;

Okay, fine.

Es geht mir nicht um die Schwankung, sondern um den Vgl. MAF and MAP!

Could it be that one value consistently exceeds the target value, while the other...?
Is the value below the target value for nearly 50% of the time within the fluctuation range?

I would actually say there's a leak here. There's too much air mass relative to the boost pressure. But that depends on how the target values were defined.
Was ist hier so präzise aufgetragen, dass man Lecks erkennen kann?

I'm sorry, I don't currently have access to the vehicle to fulfill Dieselmartin's request.
But I have an acceleration in the third gear where you can see the throttle being applied.
The other logs were started at the same time as the throttle was engaged. You can still see the pressure building up.

Important:
I'm aware of the weakness in my charger. It whistles constantly anyway. I'll have it repaired next week.
That's why I also uploaded it in fourth gear in my first post. In this case, there's more of a static load condition with less influence from the charger's control system.
There, you can clearly see the problem related to my question: Does my MAF sensor match my MAP sensor?
In the third gear, I also observed instances where the target boost pressure was not reached. Nevertheless, here is the log data from the third gear.

Could it be that one value is consistently exceeding its target value, while the other...?
Is the value below the target value for nearly 50% of the time within the fluctuation range?

I would actually say there's a leak here. There's too much air mass relative to the boost pressure. But that depends on how the target values were defined.
Was genau wurde hier angewendet, so dass man Leckagen ableiten kann?

Hello,

Yes, it's possible that the actual value is permanently above the target value, and this is particularly advantageous when it comes to air mass.
The target value for air mass is the minimum expected air mass value for a given operating condition. This value is necessary to achieve the 'normal' expected engine performance and to avoid entering the smoke limitation zone.
If you increase the air mass, you move further away from the smoke limit. This can result in a simpler, smoke-free combustion, or, with appropriate programming, it can allow for an increase in fuel injection, which can be enabled when the diesel quantity is limited solely by the smoke limit.

It only becomes problematic when the expected air mass is no longer reached, as this reduces engine power.


Why do you think that too much air mass is being introduced?
The behavior of the air mass and the regulation of the boost pressure are quite proportional to each other.
As long as these trends are similar, the IMA is working correctly. (However, for complete verification, the control signal of the LD regulation should be used.)

Best regards, Jochen.

[edit]
The reason your data (the boost pressure increase) looks a bit strange is partly due to the low sampling frequency (0.75 Hz!). If the MSG (presumably a monitoring system) reads the actual data at the wrong time, it can result in unusual curves, which would look completely different at a sampling rate of 2 Hz.

The air mass and boost pressure are oscillating together, so everything makes sense.

m;

Thank you everyone, first of all...
In the case of a leak without a membrane effect, the MAF and MAP values are proportional.
Membrane effects can occur in hoses. However, there can be no membrane effect in, for example, the liquid cooling system (LLK).

If I have a clean, small hole in the intake manifold, then, in my opinion, the MAF (Mass Air Flow) and MAP (Manifold Absolute Pressure) values are nicely proportional, with the MAF always being very high and the MAP always being very low.
Is that what I see in the log of my first post? Am I wrong?

But the values aren't "very high" or "starving" – don't let the target curve bother you.
And most importantly, they tend to stabilize!

It's quite simple with AFN:
Air mass is measured at the very front, while boost pressure is measured almost at the very back (as far as I know, in the pressure pipe next to the engine - and even on the 1Z model, it's located at the intake manifold).

That already provides perfect monitoring of the route.

m;

What do you understand by the term 'membrane effect'?

If you want to be absolutely sure, log the turbo control. If it reaches its maximum without the desired load (LD) value being reached, you have a leak. (However, this is not the case for you.) If it goes very high, but you do reach the desired load value, you have a small leak. (You won't notice this while driving, as all target values are being met.)
In such a case, the normal behavior of the turbocharger changes:
He is approaching the target value 'from below' without being able to overshoot it.

The air mass deviates significantly from the target value when you blow air near the intake manifold. Your readings look very 'normal.'

If that's not enough, perform a visual inspection. Any cracks, leaks, or other defects in the LD ring can be easily identified by the oil that is leaking out.

Best regards, Jochen.

Well, Martin was faster again .

Thank you all.
I'll be logging with the new turbo next week and will post any significant differences I observe.

Greetings.