Adaptation Limit Reached: Adjustment Needed

Good day


I'm having a small problem with an Audi A4 Avant automatic, ADR engine (1.8 125 hp), manufactured in 1996.
The error code '00561 - Mixture adaptation (add) - Adaptation limit exceeded' appears when the engine has been idling for a while.

In the measurement data blocks, the value 'Learned mix from (add)' in the 'Lambda Learning Values' field is permanently at -11.7%, which represents the control limit (Normal +/- 10%).

Initially, I suspected the mass airflow sensor (MAF) - 4.25 g/s of airflow at 860 RPM seemed a bit high. I tested other MAF sensors: the result was the same!

I thought so.
It's probably a vacuum leak somewhere. I replaced the crankcase ventilation hoses a while ago, but there are several places where a leak could occur.
Bought a new intake manifold gasket, removed the intake manifold, and searched, but as expected, found nothing.
The hoses that I had replaced before were all fine.
The gaskets for the throttle body, intake manifold, and intake pipe looked okay, but I replaced them anyway.
Seals on the fuel injectors, also okay.

Well-built and running smoothly.
And still the same.
Thinking for a moment... 'Undernutrition' actually means 'too fat,' not 'too thin.'
Okay, additionally introducing a vacuum leak, the value fluctuates between -11.7 and -10.6.
Increasing the fuel pressure slightly reduces the injection time to 2.50ms... Adding a little more air increases the injection time to 5ms...

I'm a bit at a loss.
What kind of pain is the box experiencing?

Does anyone have any ideas?

Hello!

My neighbor has a similar car.
There were also several instances of the "mixed adaptation - adaptation limit" error.

It's not happening anymore, but I don't know why.

I have cleared the error code multiple times, cleaned the throttle body, and reset the system.
It didn't help immediately.
Furthermore, the error consistently occurred in a specific location, namely near a high-voltage power line directly above the road and a nearby mobile phone tower.
Meanwhile, the high-voltage power line is located elsewhere; it was only a temporary construction.

He also had the problem of a frozen brake booster.
I think it's possible that the engine occasionally got a bit of water in it.
and perhaps the oxygen sensor reacted to it.

I can't pinpoint the exact cause.
However, this error has not occurred again in over a year.

Good evening, or 'Good night' .

The whole thing also appeared relatively suddenly.
Hatte vor ner Weile den Motor auseinander. Darauf war der Fehlerspeicher immer leer. Never had any problems.

However, there's always been a significant fuel consumption. This thing happily guzzles fuel, consuming between 10 and 13 liters per 100 kilometers. Of course, the AG4 automatic transmission contributes to that.
But even so, that's a lot.

As far as the educational value is concerned.

It stays at the regulatory limit until 12:00 PM.
Starting at approximately 1500 RPM, the air-fuel mixture adaptation shifts towards -5.0%. At 2200 RPM, the adaptation is -0.7%, and at 4000 RPM, it fluctuates between -1% and +2%.

A peculiar vehicle.

'I think there's a vacuum leak somewhere...'
Idling is noticeable with the valve closed and at increasing engine speed.
As the throttle valve opening increases, the vacuum decreases.
less, which is also accurately reflected by the values shown here.

That doesn't fit with the error, though.
The impedance matching is in the negative.
The error is 'UNDERFLOW'.

I'm actually familiar with the issue of the engine running too lean due to a vacuum leak. Here are the symptoms:

- Oxygen sensor - Limit exceeded.
- Mixed matching - Adaptation limit exceeded.

The bucket is telling me something, but I can't quite make it out.
That confuses me a bit.

[Translating...]http://wiki.ross-tech.com/wiki/index.php/00561

Okay, I'm ready. Please provide the German text you want me to translate.

Hello everyone

Let's get straight to the point:

Positive values indicate that more fuel is injected to reach the desired lambda value (the engine is running too lean). Negative values indicate that the engine is running too rich, and less fuel is injected.

Since it's consistently in the -11% range for me, it suggests it's running too rich, and it's constantly trying to lean out.
Interesting.

The air mass and temperature readings are consistent, although I find the air mass value of 4.3 g/s to be a bit high.
I've already tested a different LLM, and the same error persisted.
Hmm, then it could only be a problem with the BDR (presumably referring to a specific component) or the nozzles.

Funny!

Hello,

"A leaky injector? That would also explain why the problem is particularly noticeable at idle, when the fuel flow is low."

Best regards, Rainer.

The candlestick pattern might provide some clues.

The candle image might possibly provide some insight.

I will definitely take the nozzles out again and check them again.
The spark plugs show a surprisingly good combustion pattern in all cylinders. I would describe the color as 'German Shepherd brown.'

Recently, I drove almost 700 kilometers in the car.
With a high average throttle usage, it consumed approximately 10 liters per 100 kilometers. (Short AG4 automatic transmission / DSP disabled, forced Eco mode).