Fabia RS PD 170PS starker Leistungsverlust | Posts 128+

@ulf

Engine control unit (ECU) optimization: €416.67 + VAT (€20), total €500.

Tuning specifications: 165 horsepower, 370 Nm of torque (+/- 5%).

Statement from the mechanic: approximately 170 horsepower and around 400 Nm of torque, "based on their experience with ASZ engines."
Just say what you were told.

Test drives with the 2.RS were conducted at altitudes ranging from approximately 700 meters to a minimum of 1100 meters, with a maximum load of 1100 kg. As mentioned, it over-revved in 3rd gear. Otherwise, with an engine temperature of around 90 degrees Celsius and an outside temperature of about 20 degrees Celsius, "all fluids are original." A mechanic from a Skoda workshop drove the car and reported "minimum 1.5 bar - 1.6 bar oil pressure, everything without any smoke."

I'll do the LOG shortly.

LOG trip, August 10th, 7% incline, 17°C outside temperature, mostly using 3rd gear.

LOG: /download.php?id=1646

To the professionals:
Could it be that his engine's settings are correct, but the target boost pressure (and actual boost) isn't reaching 1.6 bar because the boost is already being reduced due to altitude (or low air pressure)? In other words, the tuning maps might be okay, but the tuner didn't adjust the altitude compensation feature to avoid the risk of damaging the turbocharger?

What happens when a vehicle (let's say in its standard configuration) enters this low-pressure zone? How is the boost pressure reduced – through a target value, or also via duty cycle? Does it remain permanently in the soot reduction mode, or are other parameters like engine speed and driver demand also adjusted? Or put another way, how can you tell if you don't have the specific boost pressure value memorized?

If my questions are too silly, just ignore them . However, depending on the answer, it could be an indication of how to evaluate the file from super7 .

So, if you do a rough calculation based on Ulf's information, you would see a reduction in boost pressure of approximately 0.17 bar at an altitude of 2500 meters above sea level. I consider this to be realistic.
Seriously: 1300 meters above sea level isn't really a high altitude.

If super7 only increases the boost pressure by 0.1 bar, that's certainly not much, but there are some well-known tuners who don't increase it by much either.
Then I wonder why a pressure of 1.6 bar is expected. Furthermore, achieving an additional 35 horsepower with only a 0.1 bar increase in boost pressure using the IMA system is very difficult and likely unrealistic.
Perhaps that's why the performance simply doesn't work.
Is this file not programmed to handle this functionality?


Dear Mr. Antje,

When the altitude-based boost pressure reduction kicks in, the target value is reduced, which also lowers the duty cycle to regulate the boost pressure. The injection quantity is then determined by the smoke limitation system. The torque and driver demand do not need to be adjusted because the protection mechanism only affects the turbocharger.

I'm going to jump into that puddle with both feet now.

Okay, we started with an engine that was running well after being tuned. Suddenly, problems arose -> the VAG-COM diagnostic tool showed excessively high long-term fuel trim (LTFT). We searched for a solution for what felt like an eternity, replaced the control unit, retuned it, and now everything is working correctly.

@ Jochen_145: So, the 1.6 bar reading is given as a comparison value from another vehicle of the same type. This particular vehicle shows that value, or rather, the sensor indicates it .

The tuner claims 165 horsepower +/- 5%. Based on what Super7 said, I would guess that the engine actually produces this power (although not the 170 like the previous chip). If we take a pessimistic view and calculate 165 - 5% = 157 horsepower, that's still a reasonable estimate. Also, as far as I remember, tuner specifications are usually based on sea level conditions!

Okay, since this engine with the old control unit has been running for a while now and the engine wasn't performing optimally, I think both the engine and the turbo need another "break-in" period to function as they should.

Since the engine control unit (ECU) was replaced and now has different software, I find it perfectly normal that the engine doesn't run as well after the chip tuning compared to how it did with the old ECU and chip.

Regarding the LLT (Low-Level Torque), well, you can criticize me all you want, but it doesn't affect VW or Skoda at all how high it is. The best proof is that even the new control unit doesn't go into limp mode... so, the engine is running as it should. (That's what a qualified workshop would tell you.)

To give you another tip, something I'm currently thinking about, it could also be that the exhaust gases are getting stuck at the catalytic converter (or muffler), and that's why the temperature is rising because the exhaust gases can't escape quickly enough. For testing purposes, considering all the work you've done so far, you could probably remove the catalytic converter and create new logs.

Have fun, and no hard feelings.

super7 wrote:

Statement from the mechanic: approximately 170 horsepower and ~400 Nm of torque, "

according to their experience with ASZ engines.

Jochen145 wrote:

" I think the 400 Nm figure is just a marketing gimmick... honestly, the torque boost around 2000 rpm isn't much stronger than in stock trim, and it only really shows a significant improvement at higher RPMs with the tuning. "170 horsepower might be achievable, but it would require some effort, especially if the engine already has a good power curve from the factory."

So, if you do a rough calculation based on Ulf's information, you would have a reduction in boost pressure of approximately 0.17 bar at an altitude of 2500 meters above sea level. I consider this to be realistic.}.
2500 m üNN sind ca. 700 mbar -> max. LD Soll laut Software = 2075 mbar = 275 mbar Reduzierung des max. LD, at 2500 rpm.

The top end is even more heavily truncated (data for 4000 rpm).
900 meters above sea level -> 2070 millibars maximum relative air pressure, instead of 2320 millibars at standard atmospheric pressure.

1300 m üNN -> 1965 mbar max. LD

2500 meters above sea level -> Maximum load: 1700 millibars.

@ Jochen_145
Okay, thank you. All questions have been answered except for one.

Jochen_145 wrote:

@ Mr. Antje, When the altitude-dependent boost pressure reduction kicks in, the target value is reduced, which also decreases the duty cycle to regulate the boost pressure.

I didn't express myself clearly there. When the target value is reached, it's clear that a change in the duty cycle is needed. I was referring to the pre-throttle characteristic curve. Otherwise, shouldn't there be a large overshoot when reaching the target load demand (LD)?

@mserge

The tuning was done in February.
As it got warmer, the problems with reduced power and excessive smoke appeared after approximately 7000 km, eventually leading to a limp mode. Removing the tuning didn't eliminate the power reduction; only the smoke was barely noticeable, even under load.
"Parts, parts, parts were submerged until a new TCU (Transmission Control Unit) came along and provided a solution."
With the new engine control unit (ECU), it runs great, even in the higher RPM range, starting from around 3500 RPM.

After another round of adjustments, it runs better but also sounds more muffled than in its original state or with the previous tuning. At 2000 RPM, the "bump" is not as pronounced as it was during the first tuning. In the higher RPM range, it runs better than before, but still sounds quite "muffled," which I noticed during my last test drive.
I can't clearly identify any performance differences compared to the initial tuning and ECU remap.
The characteristics have changed, especially in the upper range, and there's noticeably more power even without any tuning.

*Define "pretty hazy": Intense gray clouds appear during acceleration changes and are visible in the rearview mirror as a "gray haze."
It doesn't get completely dark, but I don't think it's verschandeln enough. The exhaust is visible.
They could also be deposits that are first burned.

The professionals likely see more than just a gut feeling when looking at the LOG data.

Normally, the car is moved between 600 and 900 meters, which is where problems also occurred.
Cloudy and reduced performance with the first tuning attempt.
It was only for testing purposes that mountain roads were used to simulate the LLT (Low-Level Trigger) at higher ambient temperatures, in order to troubleshoot issues. "Low data density."

The problem persists even at 700 RPM, and also occurs with a new ECU that has been tuned, which is not acceptable.
My assumption is that the total amount of diesel with LD (Low Dust) additive does not fit.

Tomorrow I have an appointment at 8:00 AM, and then we'll see what Tuner has to say about the case.
The fact is: The 2.RS is running, and mine isn't "significantly better and smoke-free."

super7 wrote:

The fact is: The 2.RS runs, and mine doesn't , and it's "significantly better and smoke-free." Bitte gib mir den deutschen Text, den du übersetzt haben möchtest. The 2.RS is running from the same tuner with 1.6 bar of boost and no smoke, for 60,000 km without any problems.

Apparently, even that is not a guarantee that you will get the same software .
It seems only two different people created the tuning files, and one of them doesn't really know what they're doing...

Theoretically, they should be the same files.
I was actually there when he uploaded the files, and there was only one file for a Fabia RS with 131 horsepower (ASZ engine) on his computer.

super7 wrote:

Theoretically, they should be the same files. I was there myself when he uploaded the files, and there was only one file for a Fabia RS with 131 horsepower, engine code ASZ, on his computer.

Nevertheless, the other researcher might have received a "manually refined" version of the software, which may be stored on a different laptop.

[edit]
I just reviewed your various logs again: there's a lot of data, but it's not very informative in terms of extractable content because it contains a relatively high proportion of partial load and thrust values.
What particularly bothers me is the formatting as text and the use of a period as a decimal separator. This makes it impossible to perform calculations within the table (e.g., LD actual value minus setpoint) without first painstakingly converting each column from text to numbers using the "Text to Columns" feature.
Charts also require numbers instead of text.

Please provide the next logs with regular numerical data, otherwise people will quickly lose interest in viewing your uploads.
[edit]

Problem still not solved!

The car has been at the tuner's shop for half a day now.
The manager took it for a test drive and only said: "Good performance, but the paint job is not okay."

The car has been returned to its original production state. "No error codes found."

Boss to the problem:

Please schedule an appointment for approximately a two-day stay at the workshop.
The car is first tested on a dynamometer in its stock condition to definitively rule out any hardware problems. "In his opinion, there's likely a hardware issue because the same problem persists even after reflashing the engine control unit (ECU), which would normally indicate a software problem." "He says it's very rare."

If everything fits as expected, the car will receive a custom setup on the dynamometer, which will be optimally tuned for this engine and hardware configuration, to compensate me for the inconvenience.

"There's a catch to the story:"

If there's a hardware incompatibility issue, I will cover the costs of testing, labor, and parts.

Hopefully, it's not a problem with the PDE unit of cylinder 4. It had already drawn attention from the Skoda workshop, but they deemed it to be within acceptable limits or within the tolerance range.
Idle correction value for PDE: cylinder 4 with +0.8 and cylinder 3 with -0.2.
all others, discreetly.

So, we'll continue next week.
I'm really hoping for a software bug or incompatibility with my heat pump system.
In this scenario, euros are tumbling.

@ulf

I'll take another look at the logs to see how they work properly.
I thought I understood it. "A graphic would be perfect if I can manage to add one."
I'm more familiar with computer hardware than I am with software .

Thank you for any help!

super7

super7 wrote:

The problem is still not solved! The car has been at the tuner's shop for half a day now. The boss took it for a test drive and just said: "Performance is good, but the color is not okay."

Does the AGR close properly?
Certainly not any "vacuum" leaks (see Skywalker's LLK hole?).

"

Quote:

"In his opinion, there's a hardware issue because even after reflashing the TCU , the same problem persists, which usually rules out a software issue. "Very rarely," according to him

".
Aha: When a low-quality tuning file repeatedly causes the same problems in a row (instead of resolving itself), the blame is often shifted to the hardware .
Or how should one interpret that?

@ulf

I haven't made any progress yet with the optimizations; I need to disable the AGR (Aktivkohlefilter), seal the LDA (Ladedruckausgleichventil), and seal the LLK (Ladeluftkühler).

The AGR and throttle body should fit. The parts were replaced by a Skoda workshop.

Luke Skywalker: My pressure test at 2.5 bar revealed a leak. The clamp on the intake manifold then came loose.

Has the tuning file been played multiple times?
Theory Possibility: When talking about tuned turbo engines, one might also refer to them as "blown" engines. If this behaves similarly to inflating an air mattress, then repeated "tuning" should theoretically result in more LD. Theoretically, of course.

If the tuning file was of poor quality (class 2), will I get a better one (class 1) after it's tested on a dynamometer?
I hope my little one doesn't wreck the test bench .
Should a Maha dynamometer test stand have a "funny name" for up to 1000 horsepower, all-wheel drive ?
I will point out to him that the pressure should be around 1.5 bar.

Are you sure the turbo can still generate the necessary boost pressure?
Your engine has the fuel injectors from the ARL model, and those are sufficient for 170 horsepower.
However, you would then have to run a boost pressure of 1.6 bar to remain within the legal limits. I don't think the GT1749VA turbocharger will last long without damage under those conditions. Moreover, I strongly suspect that the car doesn't produce 170 horsepower, but significantly less. I find it very doubtful that the high boost pressure is being controlled by simply disabling the protective function. Furthermore, other vehicles with the same engine (e.g., ULF's Polo) don't seem to have these problems. Could you please post the part number? It's possible that your intercooler has been replaced with a more efficient one.
Otherwise, I would like to think about a more effective LLT (Lambda Value). I have an LLT setup in my modified Golf 3 TDI ARL, and my LLTs go up to a maximum of 30° above AT (Air Temperature). Keep in mind that with a higher LLT, you can burn much more fuel cleanly than you currently can, and this *without* significantly increasing the boost pressure. This would put a lot of stress on the VTG (Variable Turbine Geometry), which it doesn't like at all and can be severely damaged by it.

Updating again:

The tuner isn't working properly. I haven't yet scheduled an appointment for what hopefully will be the final fix. Holidays and a lot of work are the excuses being given.
Hopefully, something will happen next week.

Distinguishing features:

Ich reagiere zur Zeit wohl ein bisschen überempfindlich gegenüber jeder kleinigkeit, die Kiste zieht mir den Nerv. LPerformance is okay.

When starting the engine in cold temperatures (around 5 degrees Celsius), the first 5 minutes of driving feel rougher and louder than ever before.
When running at operating temperature, it sounds normal except at low RPMs around 1300-1500 RPM, where it runs quite rough. It "sounds like a knocking/clattering." At higher RPMs, there are no noticeable issues.

The same noise occurs when turning off the engine. It initially happened only occasionally, but now it happens constantly and is accompanied by a good second of afterglow from the engine, or rather, after-running. I think it could also be coming from a faulty engine mount.


I'll have to forget about any delivery trips for the next three weeks, as my HP laptop is going in for repairs starting tomorrow. The spacebar has been malfunctioning for two months now. I was sure that everything would be fine with the control unit, so I scheduled a repair appointment. Well, you can often be wrong.
3 weeks without a laptop.
I'll have to rely on my gut feeling and a thorough check for any unusual noises during the initial test drives to see if everything is working correctly again.