Kaltstartprobleme bei niedrigen Temperaturen, 2.0TDI | Posts 16+

So...

Unfortunately, the sensor is located in a completely different place on the A4.
It's so tightly packed that you can't even get to the number to read it, let alone remove it. Is it really impossible to read the information from it?
http://stefan.localh0rst.net/albums/album02/IMG_0044.sized.jpg

However, I performed a forced regeneration today and logged channels 68, 67, and 70.
It took almost 30 minutes, and I thought the light wouldn't turn off at all.
At idle, I'm now getting a differential pressure of 5-8.

The loading coefficient has decreased to 0.0%.

On the way back, I achieved a fuel consumption of 4.9 liters per 100 kilometers for the very first time, which I've never managed before! (Not even close).
http://stefan.localh0rst.net/albums/album02/IMG_0051.sized.jpg

Okay, I see the differential pressure sensor in the photo above, and if the resolution is better, you could even read the TN .

Where, on the right or left side of the image?

Are you here by chance? (Is that the one in the upper right corner of the engine room?)
http://stefan.localh0rst.net/albums/album02/IMG_0047.sized.jpg

Well,

Ah shit... I don't have a picture of that exact thing .

I just tried zooming in on the original image, but it's too blurry.
I'll check it out tomorrow.

Stefan_2.0TDI wrote:

where, on the right or left side of the image? Are you here by chance? (Is that the one in the upper right corner of the engine room?)

You might need this information someday: This is the boost/temperature sensor.

This is an intake manifold/boost pressure sensor .
It also measures a 'differential pressure', but not the one from the exhaust .

Okay...

Okay, here's the picture of the correct sensor.
However, the new sensor with TN index 'A' is already installed.
The question is whether I should just replace it.
http://stefan.localh0rst.net/albums/album02/IMG_0057_1.sized.jpg

It doesn't really cost much at 36 euros.
After the forced regeneration, it ran really well, but just 50 km later, it started running like it did before. The fuel consumption went back to being around 6-7 liters.

Hi Stefan,

Is there anything new here?

m;

Hi Martin,

As you can see in the picture, the correct sensor (Index A) is installed.

However, the car only ran well for a short time after the rain, and unfortunately, the fuel consumption has now returned to its usual, higher level.
Cold start problems have improved; it no longer stalls, but it still makes a noticeable effort when starting.
My Golf IV with the ARL TDI engine started even better after 250,000 km.

Should I replace the sensor as a preventative measure?
The pressure difference readings have significantly decreased at idle. They are now showing values of 2-5.

I will get back to you in about an hour with the LL (load limit) values for my trailer.

m;

ok http://www.a4-freunde.com/smf/Smileys/default/daumen.gif

'If needed, I also have some logging data from my BPW system, including data from the initial burn-in period.'

I'm only reading about cold start problems here, and so far, the only thing being considered is the DPF (Diesel Particulate Filter).

Have the basic things even been checked yet?
- Ensure fuel lines are free of air before starting a cold engine.
- Valve timing
- Starting speed
- etc.

There's a good technical article on this topic that I would recommend you check out, at least to get a general understanding of the key points. To me, it sounds more like potential leaks in the fuel system, which could allow air to enter after a long period of inactivity.

PS: I'm also personally interested in DPF issues, because mine reached its maximum capacity of around 60mg after about 40,000 km. However, I don't think the DPF is related to your starting problems.

Regards,
Guste.

Of course, I had already been looking for the error in other systems beforehand.

Starting speed is OK.
Spark plugs in good condition.
Fuel filter is new.
System virtually bubble-free (a few are normal).
Battery is okay.

I couldn't test the starter motor; I wouldn't know how to do it without removing it, and besides, it normally starts fine.
The only unknown factor in the system was and still is the DPF, which is why I created this thread.

'Long parking times were actually never an issue. Sometimes, just 9 hours on the company parking lot was enough. That's why I doubt there's a leak in the fuel system. And if there was, it would be a very significant leak, something that would be immediately noticeable.'

Okay, please provide the text you would like me to translate from German to English.

I waited a bit longer because I didn't want to spend 5 seconds logging data from an extremely cold engine.

Freshly registered, 51 km since registration (16.26 g of ash).

minimum differential pressure 4.5 mbar (5.6 mbar is the next largest measured value).

m;

My lowest differential pressure reading during the free-flow test was 2.55 at the end.