ARL Performance Issues Below 2000 RPM

Hello everyone!

I have less than 2000 1/min of thrust compared to what was originally available. In this range, it feels like it's happening in a naturally aspirated diesel engine, because the engine is very slow to rev up. My turbo boost indicator also only shows about 0.5 bar.

However, if I exceed 2000 rpm, the boost pressure increases sharply immediately, and in overboost mode, it reaches approximately 1.7 bar, causing the car to accelerate significantly.

When driving at full throttle and maximum speed, I noticed that the pressure is no longer 1.5 bar as it used to be, but only 1.3 bar. Consequently, the engine feels a bit sluggish at higher RPMs.

I checked the mass airflow sensor, but it shows a value of approximately 730 when briefly giving it full throttle at idle, which suggests that the MAF sensor is likely functioning correctly.

Who can give me assistance with this problem? } } }

Hello,

Quote:

I had checked the mass airflow sensor, but it shows a value of approximately 730 when I briefly give it full throttle while the engine is idling, which should indicate a relatively intact mass airflow sensor.

The measurement method is useless.
In the technical article https://community.dieselschrauber.org/en/viewtopic.php?t=3128, the framework conditions are described, but unfortunately, the ARL (Arbeitslosenregister, unemployment register) is not listed.

Is the turbocharger system airtight?

Best regards, Rainer.

Thank you.
I took a look at the table. Does this mean I should check the air mass during idle, since there are no data entries for full load? Can the problem be detected during idle?

How can I check if the system is leak-tight?

Of course, are the full load data entered? Please check all the measurement blocks.
For example, the ASZ (130PS TDI) engine has a typical value of 900-1250mg per injection.

Intake manifold leak after the turbocharger: Oil mist/oil stains on the pipes/hoses, louder turbocharger noise.
Ideally, insert plugs into both openings (after the charger and before the intake manifold) and apply compressed air. This will definitely help you identify where the leaks are.

Best regards, Rainer.

OK.

I looked at measurement block 3, but you mentioned block 10. However, both times, the values listed are for air mass.

Okay, I'll test these values in 3rd gear under full load. Unfortunately, I can't do it until next week, as I don't personally have a VAG-COM device.

'I don't see any oil mist on the outside of the hoses, but the pressure hoses are oily on the inside. The workshop said that this shouldn't happen, but it's supposedly unavoidable. They claimed that all TDI engines do this!'

Where exactly is the oil mist from the crankcase ventilation supposed to go?

Rainer K. wrote:

Are the data entered for full load? Please check all the measurement blocks. The ASZ (130PS TDI) engine, for example, has a typical value of 900-1250mg per stroke.

Hi Rainer,

I've gotten into the habit of using VAGCOM to read the desired mass airflow value directly from the engine control unit (instead of from a table). There are actually (at least in the ALH and AFN engines) two mass airflow values in the AGR measurement block: desired and actual.
As long as the actual value is not below this target value, a performance loss due to air mass should not occur, regardless of what is stated in the table.