Golf 4, 90PS, ALH - Fehler Spritzbeginnregelung | Posts 16+

He probably just started the boosting process too early, outside of the tolerance range. The question is, how did that happen?
Let's see what he says about the carburetor's adjustment screw and what his baseline settings are when the engine is warm.
Herbert.

Hello, I might not be able to check the KW screw until today or tomorrow. How do I measure the resistance of the fuel injection start valve? Should I place the ohmmeter probes on the valve and connect the other end of the ohmmeter to ground?

Hi there.
You need to take measurements on the lines leading to the control valve, not the lines leading to the shut-off valve. The connector is likely a 10-pin connector, and the relevant contacts are #9 and #10. You need to measure the voltage between these two contacts.
You should check the KW screw using the correct socket wrench and handle. It must be properly tightened.
hg
Herbert.

With the engine cold, I disconnected the 10-pin connector and then measured the resistance between pin 9 and pin 10 on the connector that goes to the EP (Electronic Power Steering) unit. The value I got was 14.2 ohms!

Okay, let's continue with the test program.
hg
Herbert.

Okay, so I tried tightening the screw in the middle of the shock absorber with a 19mm wrench and a hammer. I marked the screw and the shock absorber with a paint marker beforehand. The screw is tight and I can't tighten it any further.

I also tested it again using the TDI Timing Checker, as you can see in the picture!

Good morning!
You shouldn't have reached for the hammer right away; it's out of place here, but okay.
The ignition timing on the engine is clearly too early, as you can see, and that's also why you're getting the error message. The ignition timing control system is unable to compensate for the desired late timing.
You can still check the injection timing now, but it's most likely that the valve timing is incorrect. What was done before? Was the timing belt changed? Is the belt tension correct?
You can check the injection start timing using VCDS as follows:
Set the machine to warm-up mode, select the basic setting, and choose measurement block 4 (only this one). Then, the injection start control will be adjusted back and forth between "Max Early" and "Max Late."
Please provide the observed values from MWB 4, including the percentage values for the duty cycle of the control signal.
Adjusting the valve timing involves checking and adjusting the camshaft, crankshaft, and electronic stability program.
hg
Herbert.

"Moen, the timing belt was replaced about 10,000 km ago, and until now there have been no problems. I've already read the error memory several times before this issue, and there were no errors stored. As I said, the car has never had any problems before; the issue simply appeared out of nowhere. I've also checked the timing belt again; the tension is correct, the tensioner pulleys and the screws on the EP (exhaust pressure) are all tight. I even tried tightening them. I replaced the diesel filter 3,500 km ago. How could the timing change? Could the EP or its components be worn?"

I don't want to go to a repair shop right away, because it will definitely cost me 1000 euros or more. They'll probably replace the entire control unit (ECU) and possibly other parts that have nothing to do with the problem, I already checked. If I can't do anything myself, I'll ask my friend, who is very knowledgeable about ECUs and has repaired several before. Maybe he can fix the problem! I'll report back later. In the meantime, thank you very much for the quick answers, and to everyone who helped me or took my problems to heart!

Do you already have the two-piece impeller?
The workshops often continue to use the old screws, but these are expansion screws and need to be replaced.
It is quite possible that, over time, the impeller has become misaligned due to screws that were not tightened correctly or are old.
Best regards,

It might be, but I'm not sure! I've got the car at my friend's place now; he's going to take a look at it. He should know what's going on by the end of the week, and I'll let you know then!

Greetings.
I'm sorry, I can't translate that word. It's not a word I recognize.

Okay, my friend says the EP (Electronic Power Steering) has wear, specifically where the injection control valve is located within the EP housing. This wear in the pump housing prevents the injection control valve from working correctly. He installed a different, used but newly sealed EP, and also replaced the tensioner. Everything was readjusted, and the car is now running as it should. The idling issue has also disappeared, which was probably related to the EP.

Greetings.
I'm sorry, I can't translate that word. It's not a word I recognize.

Thanks for the feedback! I'm glad it's working again.
Perhaps the fuel pump is now correctly adjusted. An injection timing that was set too early would have been identifiable through a precise actuator test. However, your report from October 29th, with its observations about the noise, contradicts this.
hg
Herbert.