Lupo AMF 1,4 TDI trotz Chip keine Leistung | Posts 16+

Hello,

Herbert is right; I mixed up the two images in the first post.

There's no air mass data in your log, so you can't identify anything new from it.
Because the boost pressure, air mass limits, and actual injection volume are all within acceptable ranges.

Please provide a log as Herbert described.

Best regards, Rainer.

Here are my data, with the DPF removed.

And right after that, with it integrated.

I'm going to install my LMM (likely a mass airflow sensor) in my girlfriend's car because hers is definitely defective, and I'll see what readings mine gives when installed in her car.

Is your LMM still the original one? It's not that it's showing "something," because that often doesn't affect the performance of many 3-cylinder TDIs, but it can be important for troubleshooting.

Normally, without the EGR valve (requiring a short wait or a test of deactivation), the air mass is 440-480 mg/stroke at idle.

For understanding:

It's possible that your engine is burning the normal full amount of fuel at full throttle, but if there's insufficient air mass, this can lead to black smoke coming from the exhaust and reduced power.

It's also possible that there's not enough fuel and not enough air reaching the engine, which means it won't produce any smoke, but the car will have insufficient power.

With too little fuel and a normal amount of air, absolutely nothing will smoke, but the car will still be sluggish.

Best regards, Rainer.

Here are the measurement readings from my friend's powerful Lupo, using MY mass airflow sensor (MAF).

The LMM (likely referring to a mass airflow sensor) is a Bosch part, but it appears to be in like-new condition. However, one can always be mistaken.

But it's not the DPF that's causing the problem now, right?

Biggi wrote:

But it's not the DPF now, is it?

We cannot predict the future. If that were the case, you would have noticed it while driving.

At least, the LMM shows low, but plausible values in the car that is running well.
Okay, I'll check the values in your car again...

With and without the DPF, the air mass readings in your car are roughly the same and are reasonably okay. Therefore, the DPF is likely not the cause of the problem.
The same LMM (lambda sensor) in your car and in the comparison vehicle shows roughly the same values at the same operating point, which allows us to rule out blockages in the intake or exhaust system. This also excludes a faulty EGR valve or a problem with the throttle valve.

A possible cause could be a lack of fuel supply. How long has the fuel filter been in place?
Install a transparent piece of tubing in the fuel return line to the filter as a test, and it reveals problems with foam/air bubbles due to leaks in the intake system.

How does it start? Is the reduced power always present? Regarding the fuel tank ventilation...

Best regards, Rainer.

"I replaced the diesel filter about 1000-1500 km ago during the oil change. The starting behavior is better than my girlfriend's car. At lower RPMs, it feels sluggish, but from around 2000 RPM, there's a boost that unfortunately only lasts until about 2200-2500 RPM, after which it feels like the power is limited, so you don't feel any more acceleration."

Could it also be that the fuel pressure regulator is defective?

Tell me! How can I check him if he's a potential candidate?

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/viewtopic.php?t=18838&highlight=tandempump+problems

Hi Biggi,
Okay, let's change "MKB AFM" in the title to "AMF". Then we're talking about a 3-cylinder PD TDI engine.
The term "PD" raises a few more questions.
What is the difference between the consumption reported by the MFA (presumably a measurement device) and the actual consumption?
And since we're already at it, could you please log the power consumption (MWB) for modules 4, 13, 18, and 23, both under normal conditions (LL) and under load?
hg
Herbert.

Here are the logs from the idle state.

And here it is under load. By the way, I cleaned the mass airflow sensor (MAF), and the value has now changed slightly.