Intake Flap Malfunction: Causes & Solutions

Hello everyone,

I have a Seat Alhambra from 2003 with engine code AUY. While driving, it occasionally stalls unexpectedly and then restarts as if it's not building compression. Eventually, it starts running again for a short period.
I'm now pressing the intake valve/throttle valve, which serves as the shut-off. All the vacuum hoses are in good condition.
Has anyone ever experienced a problem like this before?
There are no error codes stored in the system's memory.

Best regards,
Leon.

Theoretically possible Check...

Okay, I checked the valve and it's working perfectly.

The only stored error code indicates a negative deviation in the boost pressure control system.

Okay, so the car always starts perfectly when it's cold. But after a short time, it goes into limp mode, and if you approach an intersection or drive up a longer incline, the engine stalls.
If you try to restart it, the starter motor makes a very easy sound, but after several seconds, it starts up again.

I've now cleaned the valve, it looked really bad. Additionally, I discovered a crack in the vacuum hose between the brake booster and the vacuum pump/diesel pump, and I also replaced it. But there is absolutely no change.
I've noticed that the error seems to increase as the coolant temperature rises.
"Additionally, after restarting following a stall, the tachometer remains at 0 RPM for the first second. Could this be due to a faulty camshaft sensor, or is this normal?"
The second consideration is the diesel pre-pump. What pressure does it need to deliver to the fuel filter? Since there's no fuel pressure sensor along the entire line, no error code can be stored.
Do you have any other ideas?

Best regards and have a great rest of the week!
Leon.

Relay 109?

It wasn't the relay 109 that was faulty. But it's located in a really inconvenient place on the Alhambra/Sharan.


The problem has been solved; it seems the issue was related to the injection system.
The picture of the clogged pre-pump is attached. It's incredible what you can find sometimes.
A picture of the AGR valve is also included as a bonus.
Thank you very much for your help .

"This is what the AGR (Abgasrückführung - exhaust gas recirculation) and related components looked like from a Polo 9N3 that I had. A piece had broken off and lodged between the piston and cylinder head, blocking the engine."

I would disassemble everything here and verschandeln it thoroughly.

Thank you for your feedback!