TDI Engine Problems: Biodiesel Causes Stalling & No Start

Hello,
Here's some feedback about the cause of my engine problems with my 1996 1Z TDI.
The car had been increasingly difficult to start and sometimes wouldn't start at all.
The problem was neither the relay nor the needle lift sensor. It was simply the biodiesel mixture.
After refueling with 100% diesel, all the symptoms have disappeared.
I have always made sure not to have more than 50% biodiesel in the tank when refueling with biodiesel, but even that has now led to problems.

It seems that the quality fluctuations of biofuel have not yet been resolved.

Best regards, Dietmar.

Do you think the savings from using cheaper fuel will offset the cost of buying a new fuel injection pump? You're playing with fire! It's possible the pump is already defective (seals, etc.). Bosch specifies: NO to biodiesel.

I highly doubt that replacing the ESP (Electronic Stability Program) or repairing the existing one through minor cost savings will be worthwhile.

Please read some different opinions from those affected on this topic:

Okay, I understand. Please provide the German text you want me to translate into English. I will only provide the translation.

It's not new that a problem was caused by biodiesel, but the claim that everything will be fine in the long run after refueling with DinoDiesel is news to me!

If you haven't overused biodiesel yet, your pump might still be salvageable. Otherwise, you'll have to save up the small amount of money needed for a new seal.

Stay away from biodiesel!
(That's exactly what I'm trying to convey with my signature, not to be confused with advertising!)