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@dieselmartin and other signs of a faulty MAF sensor?

 
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BlauBaer
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Post25-03-2004, 17:53    Subject: @dieselmartin and other signs of a faulty MAF sensor? Quote

hello,

Now that Dieselmartin has explained to me what 'group 8' is all about, I immediately decided to try it out.

I've also noticed for some time that the boost pressure fluctuates (you can clearly see it on the LDA, where it rises to 1.3 bar, then drops to 0.8 bar, and then goes up to 1.1 bar before stabilizing there). Someone in this forum mentioned that a faulty mass airflow sensor (MAF) is likely the cause. However, he actually achieves the required air masses, exceeding 1000 [presumably referring to a value or threshold].

But I think my LLM is just a bit slow, at least sometimes, that's what the log shows.

I just wanted to know if anyone can confirm this.

Here's the log file with analysis.

http://mitglied.lycos.de/golftdii96/008-003.zip

and here's another one:

http://mitglied.lycos.de/golftdii96/008.zip

'Thank you.'

Best regards.


Translated on 21-07-2026, 1:18.
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dieselmartin
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Post25-03-2004, 18:30    Subject: @dieselmartin and other signs of a faulty MAF sensor? Quote

It looks okay at first glance.

YOU are not giving it enough gas!!

Okay, seriously now - almost always, the "driver" value is the smallest, and then the other values become irrelevant.

Make sure to record the data accurately when you're really pushing the machine, as the driver is the most important factor (my foot generates about 40mg, but the GRA can generate even more!!!).

Then it would be interesting to see which is lower, the torque or the horsepower.

They are usually very close together for me.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.
Transparency, Teamwork
... there was another T.

I don't know what the f*ck it was.


Translated on 21-07-2026, 1:20.
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BlauBaer
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Post25-03-2004, 19:21    Subject: @dieselmartin and other signs of a faulty MAF sensor? Quote

'Um... have you checked all the log files from the beginning to the end? There are a few instances where the speed is recorded as 40-45, and in those cases, it usually indicates that the border with Russia is nearby.'

I even had it displayed nicely with 'ok' and 'border' icon_smile.gif.


Take another look... maybe you'll notice something then.


Best regards.


Translated on 21-07-2026, 1:21.
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dieselmartin
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Post25-03-2004, 20:22    Subject: @dieselmartin and other signs of a faulty MAF sensor? Quote

Were all the values recorded with the standard AFN setting, or were any changes made during the logging process (e.g., chip, 10-cent piece, box, etc.)?

If you're having trouble with the LMM (lambda measuring module), you could try Ulf's Pierburg-22kOhm tuning.

See the technical article (something about Pierburg).


Record some data while driving at full throttle for as long as possible.

For example, a single data point (DZ test) takes almost 9 seconds to record, which means you can collect a lot of data over time.

Perhaps your turbocharger isn't able to draw in air as quickly as the EDC system expects.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.
Transparency, Teamwork
... there was another T.

I don't know what the f*ck it was.


Translated on 21-07-2026, 1:23.
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BlauBaer
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Post26-03-2004, 17:10    Subject: @dieselmartin and other signs of a faulty MAF sensor? Quote

Oops... of course, I also have a 10-cent surcharge and a boost in charging pressure.

Okay, then I'll try using ULF's LMM. But first, I'm going to test another LMM; I have one lying around.

You're welcome.

Best regards.


Translated on 21-07-2026, 1:24.
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Jan03
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Post07-04-2004, 8:08    Subject: @dieselmartin and other signs of a faulty MAF sensor? Quote

@BlueBear

Did you find the error icon_question.gif?
"I'm also experiencing fluctuations in boost pressure, especially at high RPM and under full load. However, it's unlikely to be caused by my mass airflow sensor (MAF), as it's currently being bypassed with a diode. Also, my boost valve is only half a year old."

/Jan


Translated on 21-07-2026, 1:25.
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BlauBaer
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Post07-04-2004, 17:41    Subject: @dieselmartin and other signs of a faulty MAF sensor? Quote

hi,

Unfortunately, I haven't had time to investigate it further yet.

If I find out what's going on, I'll get back to you.

Best regards.


Translated on 21-07-2026, 1:26.
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