AFN VP37 Reference Value: Quantity Setting Voltage

Hello VP37 drivers,

Since I'm currently experiencing some jerking/stuttering in my Passat Variant 4 Motion, manufactured in 2000, with the AFN 110hp engine, I've decided to put the technical article on cleaning the mass airflow sensor into practice.

With Rainer's help, I purchased the professional version of VAG-COM and, beforehand, correctly adjusted the ESP using the diagram so that I was on the blue ideal line.

I just want to check, for safety's sake, what voltage other engines, like the AFN or AVG, measure in measurement block 1, row 3, when the ignition is turned on. Maybe I can cross-check the voltage readings.

The measurement showed a value of 0.540 volts when the ignition is on (but the engine does not start).

Thank you for the information...

Simply adjust the setting based on the fuel injection amount at idle with a warm engine and no additional load (~5mg per injection).

Best regards, Rainer.

hello Rainer,

Thank you for the information.

"I also cleaned the MSW while it was still assembled to avoid having to disassemble the camshaft assembly. The only thing that was a bit tedious was soldering the 6 pins and cleaning the individual parts from the muddy mixture..."

Then, check the ESP settings.



Adjusting the MSW dosage was a bit of a time-consuming process of trial and error until I achieved the desired 5mg per injection.

After a somewhat lengthy warm-up, Frittn Joe started very smoothly, but the hesitation wasn't completely gone. To improve the starting problem when the engine is warm, I adjusted the MSW (methanol servo valve) setting to a very aggressive 2.2mg/stroke. Sure enough, it started on the first pull... but the hesitation problem was immense.

After setting the value to 5.8 mg/hub, the jolting was completely gone, regardless of the driving situation.




"However, the starting behavior was quite poor; it took about 4 attempts to start the engine. I then modified the adaptation channels for idle control, channel 2, to the maximum value – resulting in 861 RPM instead of 819 RPM. I also set the starting fuel quantity, channel 5, to the maximum. However, this only resulted in a slight improvement and was not a satisfactory solution."

By inserting two 2kOhm resistors into the coolant temperature sensor, effectively simulating a water temperature of 10°C instead of 90°C, and simultaneously reducing the preheating time to its minimum, the engine started perfectly with just a turn of the key when it was already warm. The initial test drives were smooth, without any jerking or hesitation.


But:

A problem has occurred; after about 5 minutes, the MFA (multifunction display) shows a message indicating an engine problem/workshop required, along with a flashing yellow glow plug symbol.
The car runs great, no black smoke, the charging pressure and coolant levels are correct.

What can I do about it?

Quote:

A problem has occurred; after approximately 5 minutes, the MFA (Multi Function Display) shows a message indicating "Engine problem / Workshop," along with a flashing yellow glow plug symbol... The car runs great, no black smoke, oil pressure and coolant levels are normal. What can I do about it?

Read the error codes and post them.