TDI Problems: Troubleshooting & Solutions

So, a few weeks ago, I described the issue I was having with my TDI. I haven't been able to do anything about it yet due to time constraints. However, I've already made an interesting observation:

Once it gets warmer (say, above +5°C) and it's not raining or snowing, the jolting or shaking is extremely rare and difficult to induce!
It occurs much more frequently and intensely under temperatures below 0°C and during snowfall!
Can we perhaps infer what might be the cause, or what is unlikely to be the cause?

I'll do another measurement run sometime and post the results here!

Hello.

Golfdriver wrote:

Once it gets warmer (say, above +5°C) and it's not raining or snowing, the shaking/jerking is only very rarely noticeable or can be induced! It occurs much more frequently and intensely, especially at temperatures below 0°C and during snowfall. Can we perhaps infer what might be the cause, or what definitely isn't the cause?

Search for "heavy-duty quantity setting mechanism".
It's probably clear that this effect is more pronounced in cold conditions, as diesel fuel also changes its viscosity with temperature.