Golf 3 TDI: Engine Error & Troubleshooting

Does anyone have any ideas?

'When I drive, everything seems fine and all the power is there. However, after driving for about 2 kilometers, the engine loses power, the turbocharger stops producing boost, and the engine stalls when I press the clutch.'

If you restart it, everything works perfectly again, but only for 1 or 2 kilometers, after which the problem starts again.

It's not a relay 109; it has already been replaced.
There are no errors saved either.

'The VNT (Variable Nozzle Turbine) is locked at position n75, and it's working well.'

There's also no anti-return valve on the injection pump; I've already replaced that too.

Does anyone have any ideas where I should look?

Please provide the text you would like me to translate from German to English.

Are you looking for a diesel filter?

Yes, that might be the case, but if you turn the contact off and then on again, the engine usually runs for another 1 or 2 kilometers without any problems.

Even if you turn off the contact, restart the engine, and drive away again, it will run well for about 1 or 2 kilometers.

Could this be a filter issue? I'm leaning more towards a problem with the fuel injection pump.

Does anyone have any ideas about where I should start looking?

Ventilation for the tank (in this case, more accurately, air intake)?

Best regards, Rudi.

Good idea, thank you! I'll give it a try.

The fuel tank ventilation is working correctly.

Fuel filter replaced, no improvement!

The engine occasionally stalls while idling for about 30 seconds, then restarts. After driving for 2 to 3 kilometers, it stalls again.

What else?

Fuel injection pump defective?

Is the shut-off solenoid valve in the fuel injection pump broken? Specifically, is it a loose connection that causes it to always close when a certain temperature is reached?

mwaaa, no, not really?

I'm going to take a look right away!

This coming Friday evening, I'm taking the car to the dyno (performance test bench) and we're going to systematically investigate what's going on. I really have no idea at this point.

Does the engine suddenly stall?

I don't know if the Seat 4 Motion has two tanks! We had a similar problem recently with an Audi. Diesel was being pumped from one tank to the other, and there was an additional connection that was blocked (with dirt, straw , and similar things). Under full load, it stuttered briefly and then stalled.
Diesel line leaking?

Does the engine suddenly stop?

I don't know if the Seat 4 Motion has two tanks! We had a similar problem recently with an Audi. Diesel was being pumped from one tank to the other, and there was an additional connection that was blocked (with dirt, straw , and similar things). Under full load, it stuttered briefly and then stalled.
Diesel line leaking?

Sometimes the engine cuts out abruptly, while other times it starts shaking violently, then goes into limp mode and shuts off.

By the way, this is not about a Seat Leon; Leon is my name.

This is about a 1997 Volkswagen Golf 3 with an AFN 110 hp TDI engine.

Um, sorry, whoever can read has an advantage .

Okay, I found the following on the inspection report:

'Besides the fuel, quite a bit of air is also coming through the fuel filter when you accelerate fully. This air is entering the shut-off valve in the ESP system. After a short or longer period, enough air accumulates in the shut-off valve, causing the valve to (almost) close, which results in the engine jerking or stalling.'

I tried the following:

Removed the shut-off valve, took the pins out of the valve, and reattached the shut-off valve.

So, if you want to turn off the engine, you can simply turn a key, no problem.

However, the engine is still running on a mixture of air and fuel entering the ESP. It's not so much air that the ESP runs dry, but it is still happening.

Something else is also wrong because the engine is only running in limp mode, the VNT (Variable Nozzle Turbine) is not adjusting, and the maximum boost pressure is only 1.7 bar absolute, which is far too low.

There are no errors in the error memory.

'Does anyone have any other ideas? The VNT has been manually checked; it's relatively easy to access, so that might not be the main problem.'

Well?

No solution yet?

The engine is still running in limp mode, and no error codes are stored.