Fuel consumption on the Lupo 3L

hi,
I haven't found any information anywhere, either here or on www.lupo3lclub.de, that anyone has had problems with the mass airflow sensor (MAF) in the 3L engine. Therefore, I assume that they are actually reliable, unlike those in the Passat or Golf.
However, I've now used VAG-COM to read the values displayed by the mass airflow sensor.
Okay, it's actually showing a normal reading, around 750 at most.
However, I am a bit confused about the supposed value.
The setpoint value is approximately equal to the actual value for about the first third of the gas flow.
However, the setpoint rapidly increases to 1000 starting from 1/3 of the gas volume, and remains constant at 1000 from 1/2 of the gas volume onwards.
That shouldn't be the case, right?
Did you know about that?
greetings

hello, k...

With my 3.0L engine (now at 122,000 km), I haven't had any problems with the mass airflow sensor yet, but as a reader of this forum, I've been expecting it for a long time .

What I've noticed is that the measured lambda value at wide open throttle (WOT) doesn't match the target value, and the fuel injection quantity is also too low. Could this be due to a weak lambda sensor in conjunction with the speed limiter? Strangely, the maximum speed is okay.

greetings

lupo3l

P.S. the one with the default settings.

hi,
Unfortunately, I don't quite understand the relationships and workings of the TDI engine yet, including what the mass airflow sensor (LMM) does and so on.
what is 'wot'?
I noticed something in my measurement series.
In overrun conditions, the EGR valve is closed, and its value is approximately twice the target value.
As I mentioned, the setpoint value from the mass flow controller seems very strange because it jumps abruptly to 1000 when the gas flow is around 1/3 of its maximum, and then it doesn't change anymore.
Its value is at most around 750, which is relatively normal.
Do you know anything about this 'setpoint' and why it's so strange?
or is it perhaps that the target value is no longer relevant, and that the injection quantity is now determined solely based on actual values, sensor data (e.g., knock sensor readings), and temperatures, etc.?
greetings

Here are two pictures.

http://mitglied.lycos.de/soundlupo3l/hpbimg/lmm.JPG
http://mitglied.lycos.de/soundlupo3l/LMM2.JPG
greetings

hi,

'wot' = Wide Open Throttle (full throttle at 3000 RPM, 3rd gear).

The LMM (Mass Air Flow sensor) measures the mass of the fresh air being drawn in. When the EGR (Exhaust Gas Recirculation) system is active, this mass is reduced accordingly, and more exhaust gas is directed into the cylinders. My setpoint value looks the same, but I'll check it.
I think the fuel quantity (fuel cut-off) is being reduced based on the IST value. I initially thought the low IST value was due to a clogged air filter, but even after replacing the air filter, I can't reach the target value. It looks exactly like what you're experiencing.

Sure, here's the translation:

'Hello' or 'Greetings'

lupo3l

hi,
Then I think everything is okay.
but I've been thinking.
The mass of air can also be determined based on its pressure and temperature.
So, theoretically, wouldn't we need an LLM at all, or am I mistaken?
because the 3L engine has temperature sensors before the turbo and after the intercooler.
greetings

Hello,

MeisterEIT wrote:

The mass of air can also be determined using the pressure and temperature.

No. How many kilograms of air are there at 10 bar and 20°C? Well, no idea? You're right, the volume is missing.
Does the car drive normally, or what? So, no stress .

Best regards, Rainer.

@rainer,
You're right.
I've been thinking about it the whole time and I still can't figure out what's missing.
but it's the volume.
greetings

moooop...

That wouldn't be a problem.

'druck ist klar' translates to 'pressure is clear' or 'the pressure is understood.'
temp is clear.
Volume is also important (ENGINE SPEED and DISPLACEMENT!).

'It might be a bit tricky with the turbo, but it's been proven millions of times in gas stations (%&§$§(/$&% mono-jetronic).'

CU Gremlin.

@ gremlin,
assuming that the filling is then 100%.
'By that, I mean that the full charging pressure is also present in the combustion chamber.'
greetings

Well, the flow losses and such should already be known.

You can tell if it's working by removing the mass airflow sensor. The emergency program is quite bad, but it's smoke-free .

Seriously, it's definitely not as straightforward with a diesel engine as it is with a gasoline engine. The diesel engine still has the lambda control loop to properly regulate the fuel mixture.

For a diesel engine, you would need to operate without the EGR system (YESSSSS) and limit the maximum power output to avoid compromising the excess air.
'But it would certainly be feasible. However, whether it's practical is a completely different matter. In terms of performance, torque, and especially environmental impact, this process is probably unsuitable.'

and, to be precise, we then have an old TD .

CU Gremlin.