AFB Shut-off Valve Problem?

Hello, I read about this shut-off valve in the forum. I then looked at how it works and noticed that the valve only closes when the engine is already stopped. I also observe that the engine seems to "stall" more quickly than before.

Question:
1) How can you test the valve to see if it's still working properly?
2) The valve would have to close immediately after the key is turned so that the engine shuts off due to the vacuum, right?

"Everything on my engine is still original, no chip tuning, the EGR valve is intact, only the camshafts have been replaced. However, the 'problem' with the idle control valve was already present before the camshafts were replaced."

Thank you very much.

You'll need diagnostic software and an adapter to perform a function test. However, this test won't tell you anything about the timing. Please check for any damage in the area of the vacuum hoses!

I have diagnostic software, but as you already mentioned, I can see the functionality, but the timing is not correct.

I will now test the hoses. If they are okay, I will replace the solenoid valve of the shut-off valve. Am I on the right track?

mserge wrote:

I will now test the hoses; if they are okay, I will replace the solenoid valve of the shut-off valve. Am I correct in that?

Basically, yes.

For additional verification, I would try connecting a test light to the solenoid valve.
If the light starts to illuminate when you turn the key, but the door doesn't close until later, the problem is likely on the pneumatic side.

Or the valve itself may become stuck and react with a delay.

As described in the other thread, I am currently looking for losses on the vacuum side.
To eliminate the possibility of a vacuum supply to the shut-off valve, I deactivated the entire line, meaning the shut-off valve was always open. There was no difference when the engine was turned off.

Best regards,
René

It can also be tested using the actuator diagnosis function while the engine is running (and therefore with full vacuum).
Check with a hand pump and pressure gauge whether the valve closes at approximately p=800 mbar (which is about 200 mbar of vacuum), assuming it is a pneumatic valve.
"In my case, the valve operated correctly, and the vacuum system provided sufficient vacuum pressure. However, the valve's flow rate was not as desired, resulting in excessive throttling through the valve. Consequently, the time after the system was shut down (when the camshaft vacuum pump stops and no longer provides vacuum) was insufficient to fully close the flap. See the error database for more details..."
Stay cheerful.
OlBe.