LD fluctuations and air mass normal? (Logs in upload)

Hello everyone,

"I've been driving a Golf IV TDI (engine code: AJM) for 3 weeks. The engine generally runs well, but I felt that it wasn't accelerating smoothly, but rather in spurts. Therefore, I did some measurements with VAG-COM, and it seems that the turbocharger pressure control is fluctuating significantly. Also, the mass airflow sensor (MAF) values seem a bit low at full load." However, I lack any benchmark values, so I'm hoping you can help me with the evaluation.

Logs were recorded in the 5th. Driven at full load speeds ranging from approximately 1400 to 3200, I measured MWB 3, MWB8, and MWB11 individually to assess the resolution.
/viewtopic.php?t=23956

Here's some additional information: The MSG software was reprogrammed by a well-known chip tuner by the previous owner, and the performance graph from that time looks clean. However, that was 60,000 km ago, and the charger has also been replaced in the meantime.

If you need any other measurements, I would be happy to provide them.

Greetings and thank you,
Karl-Heinz

VTG is either difficult to operate or the control system is strangely programmed.

Thanks for the quick reply, I'll check the VTG.

Are the moment limitations and LMM (line management model) values acceptable from your perspective?

No, but that's not a problem, because the log file clearly shows that the file is complete garbage. It's likely also the cause of the charger replacement and now the difficult-to-operate VTG (variable transmission gear).

Please disable your Bonanza-Russschleuder and revert to the original file. As it is now, it only produces 15 horsepower.

Wow, that wasn't the tone I was expecting to find here. I specifically tried to avoid any typos, so is something wrong with my post, or am I just having a bad day?

Regarding the topic: If the current software is truly "useless," I will definitely revert to the original version. However, it's a software modification from a reputable tuner in southern Germany, and it meets all your criteria for good software.

Well, I guess we're still allowed to tell the truth, right?

Quote:

that meets all your criteria for good software.

What are those supposed to be, and where did I write them?

Sorry, but achieving 160+ horsepower with a boost pressure of 2140 mbar on this engine is complete nonsense and will cause turbocharger damage and excessive smoke due to unburnt fuel. For information: the BPX engine, which also has 160 horsepower, requires a standard boost pressure of 2500 mbar.

The somewhat condescending tone comes from the fact that, unfortunately, there are many people who ask questions and assume that a large company name automatically means everything is great, instead of simply looking in the rearview mirror and using common sense. Of course, everything else is to blame for the damage, instead of considering the most obvious explanation.

Perhaps I should simply modify the terms of service to use standard engines for 'free accounts'. It simply cannot be the case that support should be provided for defective products from other companies.

Sure, you can, I just wasn't expecting so much "directness."

Here are the criteria (under "How do I find a good chip tuner?").
/viewtopic.php?t=3063

According to the dyno chart from the previous owner, the engine "only" has 145 horsepower, which seemed quite reasonable to me.

Karl-Heinz wrote:

Sure, you're allowed to, I just wasn't expecting so much "directness." Here are the criteria (under "How do I find a good chip tuner?"). /viewtopic.php?t=3063 According to the dynamometer chart from the previous owner, the engine "only" has 145 horsepower, which seemed quite reasonable to me.

That's because the file wasn't working correctly in the first place. The article is not by me, but by Ulf.

Generally, what you said is correct, but unfortunately, you can't know in advance what modifications were made to the engine control unit (ECU). I don't want to offend you, but I've had many customers in recent years who came from "big tuning shops." They certainly didn't come because they were satisfied. Size is not a criterion for quality.

I can only guess, but I suggest having the engine reset to its factory settings, because you'll likely keep having problems with the turbocharger. Of course, there are definitely tuners who know what they're doing and have a sense of ethics, but I cannot and will not give any recommendations in that regard.

I completely agree that you shouldn't have to fix other people's mistakes, but I didn't anticipate this particular issue when I created the post.

Thanks for helping anyway. I'll contact the tuner directly (even if it's just to re-flash the original software).