AJM: Torque Map Explained Again

Title: MKB AJM: Request for VAG-COM logs of control module 08.

Hello fellow DIY enthusiasts,

Since my Bora is still experiencing some irregular acceleration,
I would like to address the owners of Golf or Bora vehicles.
Those who have an AJM, please post MWB 08 logs or send them to me if you happen to have them .

By the way, I'm currently mainly interested in the logged torque limitation.
because I am trying to find the cause of the inconsistent behavior of the line.
Therefore, it doesn't matter if, at the time the log was created, you were experiencing other issues, such as problems with the mass airflow sensor.
The turbocharger or boost control system, which should not affect the torque limiting line, were defective.

Have a nice weekend!
herwig

EDIT 05.31: Hasn't even a small log been found in your attics and basements?

Searching through dusty folders can also be tedious .

I'd like to try again with a less demanding request; I'm starting to think that troubleshooting is becoming a constant preoccupation for me.

If it's truly a correction due to an overload protection that's distorting my torque curve, /viewtopic.php?t=9583
For example, the altitude correction – as Ulf suspects – or the limitation due to an excessively high intake air temperature: What should I be looking for?

Even with two minutes of full throttle in fourth gear, the intake air temperature can only be brought just above 40 degrees Celsius compared to the outside temperature, and the ambient pressure reading reliably displays the actual outside pressure as reported by the weather service.

Have you ever encountered engine control units (ECUs) that malfunctioned without any sensor defects and without any error codes, and if so, how can you identify the cause?

fg
herwig

A standard dynamometer graph of an AJM engine with a Digi-Tec chip probably won't be helpful to you. If it does, let me know...

Best regards,
Stefan.

herwigw wrote:

So, if it's actually a correction due to an overload protection that's distorting my torque curve, /viewtopic.php?t=9583 So, for example, the altitude correction - as Ulf suspects - or the limitation due to a too-high intake air temperature: What should I look for?

"First, compare the trend of your tachometer readings in the log with my diagram in the other thread."
If your logs are located below the chart, there is a suspicion of an emergency stop function.
It could also be caused by excessively high water temperatures, but I'm not an expert on that.

Quote:

Even with 2 minutes of full throttle in the fourth gear, the intake air temperature can only be brought just above 40 degrees Celsius compared to the outside temperature, and the value for the ambient pressure reliably shows the actual outside pressure according to the weather service.

To limit the scope from the perspective of LLT:
It only affects the boost pressure in my turbocharger system above approximately 75°C (as far as I can tell from the logs), but it doesn't change the torque.

At full throttle at 3000 rpm, my lambda value is still about 35,000 points lower, so a torque reduction due to the lambda value (perhaps the AJM engine is programmed differently) would likely only kick in at higher RPMs.

Hello herwigw,

- In my opinion, your engine control unit (ECU) is original. It's unlikely that someone broke into your car's ECU just to make you spend your entire life wondering why your fuel map is distorted. } - But you never know.)
- There are no quantity restrictions regarding intercooler temperature (which is why intercooler temperature is so important for a healthy engine).
- Besides height, there are no other adjustments for the rotation.

The first hump arises because manufacturers always strive for a consistent torque curve across the speed range, and hydraulic limitations can sometimes lead to a non-linear flow rate. The second hump is due to the requirements for pipeline type testing, which stipulate that the maximum power must be achieved at a speed X, and that the power must decrease at slightly lower or higher speeds than X.
"You will never feel these volume inconsistencies as a driver because they are too small. What you typically notice is the turbocharger's boost behavior, as this also significantly affects the acoustics, and it can feel like the car is accelerating in waves. However, if you look at the derivative of the engine speed curve, you'll see that this isn't actually the case."
What's your problem, anyway?

If it's truly a correction due to an overload protection that's distorting my torque curve, /viewtopic.php?t=9583
So, for example, the altitude correction - as Ulf suspects - or the limitation due to a too-high intake air temperature: What should I look for?
'First, compare the trend of your tachometer readings in the log with my diagram in the other thread.'
If your logs are located below the chart, there is a suspicion of an emergency stop function.
It could also be caused by excessively high water temperatures, but I'm not an expert on that.

Even with 2 minutes of full throttle in the fourth gear, the intake air temperature can only be brought just above 40 degrees Celsius compared to the outside temperature, and the value for the ambient pressure reliably shows the actual outside pressure according to the weather service.
To limit the scope from the perspective of LLT:
It only affects the boost pressure in my turbocharger system above approximately 75°C (as far as I can tell from the logs), but it doesn't change the torque.

At full throttle @ 3000 rpm, my long-term fuel trim is still about 35K lower, so a fuel trim-related torque reduction (perhaps the AJM is programmed differently) would likely only kick in at higher RPMs.

I still need to compare the values in the diagram.

So, it's unlikely to be the charge air temperature; it's good to know that it should still perform well even at 35 degrees Celsius.

I had suspected the water temperature several times, but I couldn't find anything unusual; the coolant is being circulated.
It's 87 degrees warm year-round, both in summer and winter, and maintains that temperature consistently.

Hello herwigw,

- In my opinion, your engine control unit (ECU) is original. It's unlikely that someone broke into your car's ECU just to make you spend your entire life wondering why your fuel map is distorted. - But you never know.)
- There are no quantity restrictions regarding intercooler temperature (which is why intercooler temperature is so important for a healthy engine).
- Besides height, there are no other adjustments for the rotation.

The first hump occurs because manufacturers always strive for a consistent torque curve across the speed range, and sometimes, due to hydraulic limitations, a non-linear flow rate can result.
The second hump arises from the requirement for type approval of the equipment, which states that the maximum performance must be achieved at a speed of X.
and the power must decrease at slightly lower/higher speeds than X.
You will never feel these minor inconsistencies as a driver, as they are too small.
What you typically notice is the behavior of the turbocharger's boost pressure, because this also significantly affects the sound, and it can feel like the car is accelerating in waves.
Looking at the derivative of the speed curve, you can see that this is not actually the case.
What is your problem, exactly?

@bafische:
'Pfusch' Version 0.1 Copyright by VW 2000 ?

I also assume that the car was never actually or experimentally tuned; I wasn't the one who did it.
and whether the previous owner (a retiree) had it? However, I can't completely rule it out because until now, I have...
I haven't found any objective reason why the previous owner sold a car that was only 3 years old.
I wouldn't do something like that!

The problem is that you can clearly feel the peaks and valleys of the torque curve, especially the dips.

Especially with relatively low engine power like mine, I find that even slight fluctuations...
Overtaking performance felt unsettling. In comparison, my old 1.8-liter gasoline Passat from 1986...
It was the stoic composure with which he was dressed that I found reassuring.

I've also recently ridden in an Audi A6 (with an AWX engine) belonging to a friend, and his was manufactured from 2000 onwards.
a completely uniform acceleration - I want to achieve that too .

Best regards, Herwig.

herwigw wrote:

The problem is that you can clearly feel the peaks and valleys of the torque curve, especially the dips. Especially with relatively low engine power like mine, I find that even slight fluctuations in... Overtaking performance felt unsettling. In comparison, my old 1.8-liter gasoline Passat from 1986... Wearing clothes with a stoic simplicity, THAT is what I found reassuring. I've also recently ridden in a friend's Audi AWX, which was manufactured from 2000 onwards. a perfectly uniform acceleration - I want to achieve that too

.

Hmm, my experience tells me that these imperfections are usually almost impossible to feel, but there must be something there, otherwise you wouldn't be looking for a solution.

I have another suggestion regarding excluding the turbocharger pressure control system:
Background: Acceleration with fully engaged boost pressure.
So, an acceleration test in the highest gears, starting from idle speed and going up to the rev limiter, ideally with the data logged. At the latest from 1700 RPM, the load-dependent regulation (LDR) should be active, meaning no more over- or underswinging. Now you can check the linearity of the acceleration. That is, if you still feel any vibrations or fluctuations between 2000-4500 RPM, it's definitely not the LDR.
Then there's the "thin" explanation that your hydraulics don't really operate linearly within this range of volumes/pressures. For example, if you want to increase the amount by 3mg, it might actually release 5mg. But that's a bit of a stretch.

Hmm, my experience tells me that these imperfections are usually almost impossible to feel, but there must be something there, otherwise you wouldn't be looking for a solution.


If I
I have another suggestion regarding excluding the turbocharger pressure control system:
Background: Acceleration with fully engaged boost pressure.
So, an acceleration test in the highest gears, starting from idle speed and going up to the rev limiter, ideally with the data logged. At the latest from 1700 RPM, the load-dependent regulation (LDR) should be active, meaning no more over- or underswinging. Now you can check the linearity of the acceleration. If you still feel any vibrations or fluctuations between 2000-4500 RPM, it's definitely not the LDR.
Then there's the 'thin' explanation that your hydraulics don't really operate linearly within this range of volumes/pressures. For example, if you want to increase the amount by 3mg, it might actually release 5mg. But that's a bit of a stretch.


The thing about completely regulated boost pressure is a bit complicated:
Here's the log (which I've already posted in another thread) – the yellow line always indicates that it was recorded while in fourth gear.
http://members.aon.at/835935/050514/08-10.gif

In the third http://members.aon.at/835935/050516/08_2.gif

to be or not to be:
http://members.aon.at/835935/050516/08_1.gif

I wouldn't dare to go beyond fourth gear here in Austria.
Otherwise, I might have to walk for a while, and my torque curve will be affected.
'decreases much more steeply with speed, and is also higher at high temperatures.'
even with beer-based tuning, the values can only be raised to acceptable levels for a short period .

Hello Herwigw,

Okay, in the top graph, you can clearly see the oscillating LDR.
The dip observed in the smoke-sensitive area of the lower graph doesn't indicate a very stable LDR (Light Dependent Resistor).

However, whether the oscillating LDR is actually the cause of the wavy driving behavior is just a hypothesis - I can't think of anything else.

Is the wavy acceleration level the same in all 3 measurements, or can it be limited to a specific speed range? Does it exist within the same speed range in all gears?

Hello Herwigw,

Okay, in the top graph, you can clearly see the oscillating LDR.
The dip observed in the smoke-sensitive area of the lower graph doesn't suggest a very stable LDR (Light Dependent Resistor).

However, whether the oscillating LDR is actually the cause of the wavy driving behavior is just a guess - I can't think of anything else.

Is the wavy acceleration level the same in all 3 measurements, or can you limit it to a specific RPM range? Is it present in the same RPM range in all gears?

Hello Bavarian.

I know that you are right about the bad LD regulation .
And I think it's very kind of you to take the time and not get tired of pointing out my mistakes!

I promise to fix it, as soon as possible. But can we perhaps ignore the LD setting for the moment, if it's good enough that it only engages the turning motor in most attempts?

Regarding that: I'm still unclear about how the so-called 'actuator diagnosis' (or whatever it's called) works for the turbocharger control valve: specifically, MWB 011, and whether you need to switch to the default setting, or if you need to do something else for that .

Regarding the rotary injection pump (KF) and the injection quantity:
I can now, based on my experience, quite well distinguish between the different causes of performance drops.

Occasionally, a hard 'swallowing' or abrupt change occurs at approximately 2100, related to smoke limitation.

Gentle 'loosening' for valleys in the torque curve, or a joyful 'tightening' for the corresponding peaks.

'This means that the peaks and valleys of the ignition timing curve are always found at the same RPM values, regardless of where I start accelerating. They always feel the same, and I can find them in all my logs since I started using VAG-COM (since 2004), so in hot weather, cold weather, dry conditions, rainy conditions, with and without adjustable camshaft timing...'

For the weekend, I've planned to check all the static values again (brake settings, etc.) and to review the equipment coding.
Perhaps it's worth experimenting with - but it's just a crazy idea, whether you could get a different torque curve by using a different equipment code (Ulf once tried something like this and posted about it) - for example, a 5-speed instead of a 6-speed.

Sure, here is the translation of the text from German to English:

'Hello'
herwig

hello herwigw,

wenn du ganz sicher bist (und du scheinst es wirklich zu sein) das die träge Beschleunigung nicht im einem Ladedrucktal und die freudige Beschleunigung nicht in einem Ladedruckberg liegt auch wenn du nur in der Drehmo fährst, dann werde ich das Wort Ladedruckregelung nicht mehr in den Mund nehmen. EPlease provide the text you would like me to translate from German to English.

When dealing with encodings, you won't be able to influence the rotation speed unless you have an SG with multiple destination slots (DSTs) and your rotation speed was only changed in the current DST. However, that is highly unlikely.

Have you compared the full-load values with the torque curve posted by Ulf? Do they match your values?

Ultimately, I'm also at a loss. I think it's disproportionate to go to a chip tuner to have a linear torque curve programmed.

During the actuator diagnosis (or was it the initial setting?), the engine speed is raised to 1000 RPM, and the TV (throttle valve) of the EPW (electronic power unit) is switched back and forth from 0% to 100% for the turbine adjustment actuator, while the EGR (exhaust gas recirculation) is closed. Here, the boost pressure can indicate whether the turbine is actually adjusting. While specialists can glean some information from the magnitude of the boost pressure change, no one knows exactly what it means.
Unfortunately, I don't have a VAG-Com, so I don't know how you get there.

hello herwigw,

wenn du ganz sicher bist (und du scheinst es wirklich zu sein) das die träge Beschleunigung nicht im einem Ladedrucktal und die freudige Beschleunigung nicht in einem Ladedruckberg liegt auch wenn du nur in der Drehmo fährst, dann werde ich das Wort Ladedruckregelung nicht mehr in den Mund nehmen. EPlease provide the text you would like me to translate from German to English.

When dealing with encodings, you won't be able to influence the rotation speed unless you have an SG with multiple destination slots (DSTs) and your rotation speed was only changed in the current DST. However, that is highly unlikely.

Have you compared the full-load values with the torque curve posted by Ulf? Do they match your values?

Ultimately, I'm also at a loss. I think it's disproportionate to go to a chip tuner to have a linear torque curve programmed.

During the actuator diagnosis (or was it the initial setting?), the engine speed is raised to 1000 RPM, and the TV (throttle valve) of the EPW (electronic power unit) is switched back and forth from 0% to 100% for the turbine adjustment actuator, while the EGR (exhaust gas recirculation) is closed. You can tell if the turbine is actually adjusting by observing the boost pressure. While specialists can glean some information from the magnitude of the boost pressure change, no one knows exactly what it means.
Unfortunately, I don't have a VAG-Com, so I don't know how you get there.

Hello bafische,

Perhaps I'm only starting to understand you now.

You suspect a turbocharger pressure influence, even though the air mass is sufficiently high.
This essentially represents the strict Maximin principle between the characteristic curves: the lowest value always wins - which is somehow the opposite!

Okay, then I'll start looking for a new N75, just in case - the slightly stiff VTG is still worrying me, and now I'm already considering replacing the charger at 90,000 km .

I'll be comparing it to Ulf's characteristic curve on Sunday!

Sure, you're welcome!

Best regards, Herwig.

hello herwigw,

wenn du ganz sicher bist (und du scheinst es wirklich zu sein) das die träge Beschleunigung nicht im einem Ladedrucktal und die freudige Beschleunigung nicht in einem Ladedruckberg liegt auch wenn du nur in der Drehmo fährst, dann werde ich das Wort Ladedruckregelung nicht mehr in den Mund nehmen. EPlease provide the text you would like me to translate from German to English.

When dealing with encodings, you won't be able to influence the rotation speed unless you have an SG with multiple destination slots (DSTs) and your rotation speed was only changed in the current DST. However, that is highly unlikely.

Have you compared the full-load values with the torque curve posted by Ulf? Do they match your values?

Ultimately, I'm also at a loss. I think it's disproportionate to go to a chip tuner to have a linear torque curve programmed.

During the actuator diagnosis (or was it the initial setting?), the engine speed is raised to 1000 RPM, and the TV (throttle valve) of the EPW (electronic power unit) is switched back and forth from 0% to 100% for the turbine adjustment actuator, while the EGR (exhaust gas recirculation) is closed. You can tell if the turbine is actually adjusting by observing the boost pressure. While specialists can glean some information from the magnitude of the boost pressure change, no one knows exactly what it means.
Unfortunately, I don't have a VAG-Com, so I don't know how you get there.

Hello Bavarian.

Perhaps I'm only starting to understand you now.

You suspect a turbocharger pressure influence, even though the air mass is sufficiently high.
This essentially represents the strict Maximin principle between the characteristic curves: the lowest value always wins - which is somehow the opposite!

Okay, then I'll start looking for a new N75, just in case - the slightly stiff VTG is still worrying me, and now I'm already considering replacing the charger at 90,000 km .

I'll be doing a comparison with Ulf's characteristic curve on Sunday!

Sure, you're welcome!

Best regards, Herwig

Hello Ulf and Bafische,

'At least I've now compared the logged values from my rotary encoder with the ones posted by Ulf for two different logs. It seems everything is as it should be.'
That means my Bora is running on the normal torque curve, and I probably bothered you unnecessarily with my troubleshooting – sorry!

Looking closely at Ulf's image, you can clearly see the hump at 4000, which, in my opinion, is inexplicable. I can just feel it.
But maybe I can use this to calm my perfectionist tendencies for a while.
that those at Volkswagen, in their wisdom, wanted it that way, and they probably know why - but why, really?

[Speculation mode on]
When, in a diesel engine, all influencing factors apparently converge within a certain speed range.
linear behavior, such that an attentive driver can detect any deviation from a
Since you can precisely identify a typical, appropriate, linearly decreasing quantity limitation as either a torque peak or valley, why not simply draw a straight line from 2000 RPM to 4000 RPM?
and rounds the values to fit within the available grid of parameters, if necessary.
are clearly defined by the desired maximum torque at 2000 and the desired rated power at 4000?
[Speculation mode off]


Sure, here is the translation of the text from German to English:

'Hello'
herwig