Leistungsproblem bei gechiptem AVF | Posts 16+

Yes, all the appliances were turned off.

Here are the diagrams again, showing the temperatures: charge air, fuel, and coolant.
Everything was logged during the highway drive, and ideally always under full load.

I'd like to give you more tips, but your readings look very good. The intake air temperature is low, the boost pressure is quite high and quickly stabilizes at the target value. It could be slightly better at lower RPMs. The idle stabilization is also okay. The mass airflow values are excellent; overall, everything seems to be in order.
The AGR (Abgasrückführung - exhaust gas recirculation) is not a viable option because your air mass readings are too good.
"Your electronic problems would definitely make me take notice. If so many things are failing one after another, I'd first investigate the source of the problem; it might also be related to your power loss."
Of course, other defects are also possible that are not monitored by the electronics.
The pressure differential equipment (PDE) might not be properly adjusted; possibly the seals or O-rings are worn out, but that would be a less common defect.
More likely causes would be valves that don't seal properly, worn valve stem seals, worn valve guides, or worn piston rings.
I would also rule out valve stem seals; that should usually be accompanied by blue smoke.
"While rare in PDE TDIs, a worn camshaft is not entirely impossible. Try removing the valve cover and check if there are any visible wear marks on the lobes of the camshaft. This could prevent proper cylinder filling and cause a loss of power, especially at higher RPMs. Has a timing belt replacement been performed recently?"

"Can someone explain to me why everyone is so excited about his boost pressure? Mine exhibits the same behavior; the target boost pressure isn't reached until around 2400 rpm, and until then, the soot management system is active, which results in insufficient power at low RPMs. If that's just how it is, I guess I can stop troubleshooting and get used to it. However, I've seen different logs here where the soot management system wasn't active even at 1800 rpm."

What do you think about the fuel temperature, which in the log reached 90°C with a full tank and would likely have continued to rise. I didn't even drive for very long like that. In the actuator diagnosis, I can't hear the relay for the fuel cooling pump from the control unit either. Should I perhaps check it again?
"However, what also bothers me a bit, as Mr. Antje already mentioned, is the turbo boost pressure, which supposedly isn't reached or exceeded until 2400 RPM. Combined with the Tiptronic transmission, this often results in sluggish acceleration that can sometimes make you break out in a sweat. Especially when you need to accelerate quickly, you end up having to floor the accelerator and count to three before you get the full power."
Regarding this, I sent another email to the tuner yesterday, asking if it would be possible to fine-tune the software again so that the turbo engages earlier in order to achieve the desired result sooner. The response was as follows:

"Unfortunately, it doesn't really work that way. First of all, the charger naturally has a certain amount of inertia. Furthermore, in an automatic transmission, the torque converter is responsible for only partially transmitting the load (the LDR maps are load-dependent). With a manual transmission, everything is much more responsive."

To cut a long story short, things aren't getting any better...

I'm not sure how to feel about it. Maybe I should have contacted the landlord directly back then. Well, you never stop learning.

Tobi12345 wrote:

What also bothers me a little, as Mr. Antje already mentioned, is the turbo boost pressure, which is supposed to be reached or exceeded only at 2400 RPM.

What's even worse, in my opinion, is that it's currently running in soot reduction mode. If that weren't the case, the boost pressure wouldn't bother me much in your situation.

Regarding your tuner, his statement seems strange to me. Of course, the turbocharger has some inertia, but it shouldn't be running constantly up to 2400 rpm... I also don't understand what the torque converter has to do with it. This could be due to my limited knowledge .

It would be great if the specialists here could comment on my statement (regarding soot reduction) and the tuner's statement.

I still believe the problem lies with the software. Furthermore, it's clear that all limits regarding fuel injection have been significantly increased, and even in the area where the soot limit is active, a lot of fuel is being injected. It's also possible that the torque limitation has simply been set too high; it's really a matter of fine-tuning.
Furthermore, I noticed in the initial logs that, even though the target boost pressure isn't being reached, there seems to be some room for adjustment in the duty cycle/boost control valve to further increase turbocharger speed and thus shorten the boost build-up time. However, this isn't happening, but it could be achieved through appropriate tuning maps. This should then improve both the boost build-up and low-end responsiveness; however, some soot formation would likely be unavoidable.

First of all, I'm not familiar with chip tuning.

Quote:

"But unfortunately, I don't know if it has anything to do with your chip tuning."

Zak1976 wrote:

1) I still believe it's due to the software. 2) Furthermore, I noticed in the initial logs that, even though the target boost pressure is not reached, there's still room for adjustment in the duty cycle/boost control valve to drive the turbocharger more aggressively and thus shorten the boost build-up time. However, this isn't happening, but it could be achieved through appropriate tuning maps. This should then also improve the boost build-up and response at lower RPMs, although some soot formation would likely be unavoidable.

Okay, that makes sense. Does that mean we can already talk about bad tuning, or not? But for my car, it still means I need to keep searching, since I'm sticking with the original parts, right?
"Therefore, it's not correct to blame the tuner, the turbocharger, or the torque converter for this issue, right?"

Based on points 1 and 2, one could conclude that Tobi12345 didn't choose the best tuning option. What do you think about that?

Basically, I would say (this is my opinion) that despite the tuning and log files, the performance and fuel consumption probably haven't changed significantly, unless perhaps the turbocharger was responding faster before...

Hello there!

I'd like to thank everyone who offered me advice. However, I'm still struggling with the relatively harsh starting behavior at temperatures around 15°C or lower, which I believe results in a rough and uneven idle. Additionally, the exhaust fumes are extremely smelly and corrosive.
Oh yes, and I almost forgot. He also shakes a little bit whenever I turn off the engine. Could it be related to the throttle valve in the intake manifold, or could it be because my exhaust manifold is clogged with oil sludge, which affects the combustion process due to restricted exhaust flow?
Or could it be due to the chip?
Which measurement data blocks should I record to obtain meaningful information?

Regards,
Tobi.

I'll have my mechanic check the intake manifold again to see how it looks, and possibly re-examine the piezo injectors and verify that the settings are correct.

Please disable the AGR valve using a piece of metal. Even if the hose is blocked, a faulty AGR valve can still be "forced open" or may not close properly, which could explain your "harsh exhaust fumes." The hard starting sound might also be related; possibly the timing (timing belt) is slightly misaligned. Depending on whether it's set "early" or "late," the engine noise will change, although this would only happen if the engine is running. It could also be a faulty catalytic converter (at least regarding the smell and lack of top speed).
Unfortunately, it's difficult to check this with VAG-COM.
P.S.: If you want to save some money, remove the intake manifold yourself; it's not a big job. Then you can also take a look at the inlet channels yourself.

Zak1976 wrote:

PS: If you want to save some money, remove the intake manifold yourself; it's not a big deal.

Then you can also take a look at the inlet channels yourself.
In his case, it's probably difficult }. Regarding the EGR and catalytic converter, would that have become noticeable immediately upon starting?

I've already deactivated the AGR (Abgasrückführung) system because the engine in the Passat is mounted longitudinally, so I was still able to access it relatively easily myself.
It absolutely didn't make any difference. Unfortunately!

I'm so hungry I could eat a horse!
"Over the past two days while I was driving, both in the city and on highways and country roads, I haven't seen any more black smoke. On the highway, you can see a little bit of it when accelerating with the kickdown function, and above 4000 RPM when revving the engine, but that's also because I recently installed new exhaust pipes."
The only things that haven't changed are the engine starting behavior and the smell of the exhaust fumes.
I'm soon going to reach a point where I can't explain anything anymore.
"Whatever, I'm just glad that at least one problem is off my plate now."