Sharan TDI (AFN) won't start

I bought a Sharan TDI with 110 horsepower two days ago.
On the first day, everything was fine. The engine was running perfectly.
This morning, I drove around the corner to the bakery, and when I tried to leave, the engine started very reluctantly. It took an unusually long time to start, but it eventually did. After breakfast, I wanted to drive to work, but the engine simply wouldn't start. It doesn't show any signs of igniting. The starter motor turns the engine over properly, but that's all. The tank is full, and I couldn't find anything using my laptop quickly. There are no error codes stored.
What can I do?

Hi.

Given that critical errors that would completely prevent a mechanically sound engine from starting are usually stored in the error memory, I suspect the problem is "no fuel."

Check if the transparent pipe connecting the filter to the pump is completely full of water, or if it contains long air bubbles.

To be absolutely sure, disconnect the fuel return line from the filter and have an assistant briefly engage the starter motor; this should pump diesel fuel.
If that's the case, the fuel pump won't receive any fuel. As a test, try adding approximately 100 ml of verschandeln diesel fuel directly into the pump through the inlet line; it should then start (be careful of potential...). Fountain on the return line!

If nothing else works, the valve seat might be stuck --> unscrew it and check the valve seat for any ridges or imperfections, and smooth them out if necessary. Alternatively, you could try removing the valve stem completely, re-installing the upper part, and then starting the engine.
If then, despite diesel being in the pump, nothing still comes out and the error memory is empty, then the pump probably has a new problem .

Thanks for the tip. I'll try it tomorrow.
I've heard that the pulley on the crankshaft sometimes comes loose on the Sharan, which completely throws off the timing. I'm going to take a look at it tomorrow and post the results. But if anyone has any smart tips, please share them!

Hi.

The issue with the loose timing belt sprocket on the crankshaft was/is, as far as I know, a主要 problem of the older 90 hp engines.
Which of course doesn't exclude the possibility that it can also occur in other types.

In your case, the deterioration happened too quickly to attribute it to this problem – usually, it's a gradual process that takes weeks or months.

But it's not something you can completely rule out.
And the worst part is that an exam or... The repair should be carried out as soon as possible, otherwise a complete engine failure may occur due to a "piston-valve salad."

Okay, the gas is coming.
It still won't start, though.
I suspect it's either the control unit or the fuel injection pump.

Does anyone have any more clever tips for me?

A notebook and a VAG-COM device are available.

Stefan wrote:

so, the water is coming. He still doesn't want to start.

Hi.

I'm interpreting this as meaning that fuel is being pumped from the return line during startup.

Okay, now I'm going to tackle the valve seat/valve insert --> see my post from August 22nd, 5:10 AM.

It's running again!

after I had reassembled everything,
he suddenly started up again.
I haven't exchanged anything or adjusted anything.
He probably had an air bubble in the fuel line.
or contact problems.

Anyway, thank you for your help!

After it failed to start again, the problem has now been localized.
'Weasel bite in the fuel line. This causes air to be drawn into the line, and after a longer period of inactivity, the fuel flows back into the tank (likely due to the lack of vacuum). After 3-4 minutes of cranking and bleeding the fuel system, it starts again.'
I'm going to replace the fuel line now, and then everything should be okay.