1.4TDI AMF: Ladedruck erst ab 2800/min | Posts 16+

If you are driving up a steep hill in the 5th gear at 2100 RPM, then there will be an emergency mode because the desired and actual values have too much of a difference.


It could also be because the tuner 'forgot' that the 1.4 TDI engine has a relatively large turbocharger (similar to the one on the 1.9 TDI), which, no matter how you modify the fuel and ignition maps, only starts building boost at a certain RPM.

A few weeks ago, we saw logs from a chipped 1.8T engine where the target and actual pressures were deviating similarly for the same reason, and it also frequently went into limp mode.

It could also be because the tuner "forgot" that the 1.4 TDI has a relatively large (similar to the one on the 1.9) wastegate turbocharger, which, no matter how you modify the map, only builds up pressure above a certain RPM.

That's not entirely correct. The 1.9L engine with 74/77 kW has a KP/BV39A turbocharger, the 96 kW version has a KP/BV39B, and the 1.4L engine doesn't have an index.
Certainly the same turbocharger series, KP/BV39, but with noticeable differences in the turbine wheel and compressor wheel.
For example, the 1.9L models have a 46mm valve relief, while the 1.4L models have a 40mm valve relief.
Regards,
Dirk.

Hi Dirk,

You are describing VTG chargers here. The models with 74, 77, and 96 kW all have VTG technology.

The AMF has a turbocharger with a wastegate.

Therefore, you've made a mistake somewhere, and that doesn't invalidate Nebel's statement that it could be the same charger as the one used in the 1.9 engines (1Z, AHU, ALE, or AGR).

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

I once placed my old AMF loader next to a 1Z loader. Visually, they look exactly the same. The only differences are that the exhaust housing on the 1Z is rotated 90 degrees, and the pressure sensor has a different angle. Of course, the geometry of the internal components might also be different.

I definitely have a wastegate turbocharger. Only the 66kW 1.4 TDI engine in the A2 has a variable geometry turbocharger (VTG).
It can't be the chip. Before, around the year 2000, it also didn't go into emergency mode.

This weekend, we'll continue troubleshooting the issue.

Regards,
Thomas.

"I also experienced the limp mode issue on my old AMF with a chip while driving uphill at 2100 RPM. However, it only happened when I was using very little throttle. More throttle = no limp mode. It wasn't the control valve. After 100,000 km, the turbocharger failed due to constant overboosts (it sometimes regulated too late even during acceleration), which caused oil to leak through the shaft. After replacing the turbocharger, the overboosts and limp mode disappeared."Okay, I now have another AMF with the same chip, but with almost 110,000 kilometers on it. The turbocharger has been working correctly from the beginning, so there's no limp mode (except for one time when the control valve failed).

Regards,

Olaf.

Okay, now then .

The casting around the wastegate hole is swollen like a sponge. This caused the wastegate valve to sit crookedly and no longer close completely. I've seen a GT15 WG turbocharger before with cracks around the hole, but in that case, the valve was still sealing properly.

Thank you very much for your help!

Regards,
Thomas.

Swollen? Take some pictures, I'd like to see them.

Okay, I took some pictures.

Regards,
Thomas.

A2TDI wrote:

Okay, I took some pictures. Regards, Thomas

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The reason for excessive soot buildup in the DPF is likely due to an exhaust gas temperature that is too high (the engine control unit is tuned too rich for the LD). It's important to remember that Variable Geometry Turbos (VNT) are particularly susceptible to damage from excessively high exhaust temperatures. Therefore, it's advisable to monitor the exhaust gas temperature or use a chip that doesn't fully exploit the available air reserves.

@Aron
While I can't exactly call myself an expert, but:
You probably meant "too thin," right?
To my knowledge, many chips are programmed to inject just enough fuel under load to cause a slight amount of smoke, but in doing so, they keep the exhaust temperature from getting too high – essentially, it's seen as the lesser of two evils.
Even with a small aircraft engine, I have to richen the fuel mixture if I need full power on the ground, otherwise the engine will overheat.
It would be news to me that an overly rich fuel mixture could cause a motor to overheat, especially creating high exhaust temperatures (aside from the extreme scenario of excessive post-injection leading to the piston melting).
Sure, here's the translation:

"Maybe an expert could chime in with a couple of words for clarification. I've been using chips that don't produce any soot but still offer good performance, so I tend to be cautious."

Regards,

Olaf.

Olaf wrote:

@Aron While I can't exactly call myself an expert, but: You probably meant "too thin," right? To my knowledge, many chips are programmed to inject just enough fuel under load to cause a slight amount of smoke, but in doing so, they keep the exhaust temperature from getting too high – essentially, it's seen as the lesser of two evils. Even with a small aircraft engine, I have to richen the fuel mixture if I need full power on the ground, otherwise the engine will overheat. It would be news to me that an overly rich fuel mixture could cause a motor to overheat, especially creating high exhaust temperatures (aside from the extreme scenario of excessive post-injection leading to the piston melting). Sure, maybe an expert could chime in with a couple of words for clarification. I've been using chips that don't produce any soot but still offer good performance, so I tend to be cautious. Regards, Olaf

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You are absolutely right about homogeneous mixture formation in a spark-ignition engine. However, a diesel engine operates on the principle of stratified charge combustion. In this case, there is a large amount of oxygen available in the combustion chamber. The diesel fuel is injected, and it ignites approximately 1 millisecond after the start of injection. During the injection process and combustion, the diesel mixes with a portion 'x' of air.
The exhaust gas temperature of a diesel engine is approximately 100°C at idle. In Euro4 engines, it's slightly higher because the engine is regulated to run "richer" due to the EGR system. Under full throttle, the exhaust gas temperature can reach up to 850°C.

Well, since last Thursday, I've been using a diesel tuning chip. Therefore, I probably won't have to remove that turbo anymore .
More power, more torque, less soot, and much more 'driveable' than the old chip.

Thanks again, Rainer.

Regards,
Thomas.

New car or engine conversion (AMF)?
If that's the case, could you send me a private message with an approximate cost and performance estimate? Well, maybe Rainer himself will have something to say about it.

Regards,

Olaf.

New car or engine conversion (AMF)?
If that's the case, could you please send me a private message with an approximate cost estimate and performance details? Well, maybe Rainer himself will have something to say about it.

Regards,

Olaf.

I would also be interested in the project management role.