TDI 1Z: Engine Misfire & Lack of Power

Hello fellow inventors,

Currently, I'm stuck on this problem and can't seem to make progress.
The car jerks between 1300 and 1500 RPM and doesn't reach its maximum power.
Idle is okay.
Error code: 0575 Intake manifold vacuum, difference, interrupted (or something similar).

Here's what I've done so far:
- Replaced N75 solenoid valve.
- Checked the vacuum lines leading to the control unit, and visually inspected the others as well.
- Fuel filter replaced.
No improvement.

The injection timing is at the lower tolerance limit, and when you press the accelerator pedal during measurement, the measured value no longer returns to the graphic display area for the TDI timing.

Do you have any ideas about what I can do?

Thank you in advance, Dietmar.

Mileage?

Error code: 0575 Intake manifold vacuum, difference, interrupted (or something similar)

Please post the EXACT protocol. 'Something similar' is not helpful .

000575-17-10 - Intake manifold pressure regulation differential interrupted, therefore not intermittent.

The car has 240,000 km on the odometer, it has been driven very responsibly, and it has not been chipped (tuned).

How significantly can a misadjusted injection timing, which is slightly outside of the specified range, affect performance?
It is not impossible that the deterioration in engine power occurred at the same time as the last timing belt replacement (1.5 years ago).

However, the error message still appears.

The car feels like the turbocharger isn't working correctly. There's only a slight increase in power above 1800 RPM, followed by sluggish acceleration until 4600 RPM.

Hi,

What can help:
- Read through the technical article .
https://community.dieselschrauber.org/en/viewtopic.php?t=3285

- If there is suspicion of incorrectly adjusted timing belts: adjust them correctly. It sounds trivial, but it is. It eliminates one potential error.

- Error 575: Search helps...
and
- Create a log, and then you'll really know if the boost pressure is incorrect. In my old car, the wastegate occasionally gets stuck, and because of the excessive pressure, the engine control unit reduces the power. It feels like there's too little boost, but in reality, the boost was too high. The only way to know for sure is to log the data or use an analog gauge.

- Stuttering:
https://community.dieselschrauber.org/en/viewtopic.php?t=5517

I hope these are enough suggestions for the weekend .

Regards,
A.

Thank you for your input.

Since I don't have a VTG loader, most of the suggestions aren't relevant, and I'm still missing the key idea to move forward.

Okay, I'll proceed with measuring block 11, which deals with boost pressure, and then adjust the injection timing.
Does anyone know the adjustment range of the pump on the bracket? Specifically, at what point do you need to loosen the injection pump wheel for adjustment? Is it always necessary, or mostly not?

Hi,
Please provide the correct error message.

Quote:

The terms "intake manifold vacuum," "difference," or "interrupted" (or something similar)

do not appear in the text. Also, please remember to enter your VCDS license number, as it is a requirement for us to provide assistance with interpreting MSG information.
Your observation.

Quote:

The injection timing is at the lowest tolerance limit, and if you press the accelerator pedal during measurement, the reading will not return to the graphic display of the TDI timing.

This could also indicate a loose crankshaft position sensor central bolt. Therefore, it's a good idea to check it for safety.

Quote:

Does anyone know the adjustment range of the pump on the bracket, i.e., from what point do you need to loosen the wheel of the injection pump for adjustment? Always, or mostly not?} The wheel on the ESP is not loosened at all for adjustment on the 1Z. This would be pointless, as the wheel is fixed to the shaft by a spring. The EZP (electronic fuel pump) is adjusted by rotating the pump. Before you do that, how did you set the timing when you changed the timing belt? Having cylinder 1 at TDC, locking the crankshaft, securing the ESP wheel, placing the timing belt with the ESP wheel pre-tensioned in a clockwise direction, and having the correct timing belt tension are prerequisites. Normally, the EZP will then be correct during a dynamic test.
Sure, here is the translation of the text from German to English:

"vg"

This is a common abbreviation for "very good" in German. It is often used in online forums and chat rooms.
Herbert.

Hello Herbert,

The exact error message is: ;000575-17-10 - Intake manifold pressure control differential interrupted.

I didn't replace the timing belt myself, only on my own, identical TDI model.
There, I was very concerned back then that, after removing the protective cover, the plug didn't fit into the ESP drive wheel.
Did I make the mistake back then of not knowing that the wheel sensor for the ESP system needs to be pre-tensioned...?
Anyway, I had just replaced the timing belt on my own TDI two weeks ago, and I didn't bother with the water pump anymore. I just used plugs and adjusted the timing at the transmission, and painstakingly levered the toothed belt without loosening the ESP wheel.
The dynamic timestamp was within the tolerance and did not require correction.

I have now received the notification from Passat regarding the problems mentioned above, stating that the engine runs slightly better after replacing the N75 valve, but the 'turbo boost' issue still needs to be resolved.
VW states that the wheel nut on the ESP sensor should be loosened to make it easier to install the timing belt, which is why I'm wondering if the person who replaced the timing belt previously might have adjusted something incorrectly. (I thought the ESP sensor wheel wasn't keyed and had a conical shape!)

Okay, I'll adjust the injection timing at the pump and then test the KW fitting on the front side again.

Hi Dietmar,
den Fehlertext "...Regeldifferenz unterbrochen.." gibt es nicht. Das macht technisch auch keinen Sinn. An der Stelle können wir aber nur mit Referenz auf eine VCDS Lizenz weitermachen, sh. Forum rules.
Your method for changing the timing belt is incorrect. The timing is definitely not right anymore, and the timing belt itself may already be damaged. The crankshaft pulley must be loosened, not the ESP pulley. The sequence for changing the timing belt is as follows: Cylinder 1 at top dead center (TDC), lock the crankshaft with a ruler (you may need to rotate the crankshaft slightly), lock the ESP with a pin, loosen the crankshaft pulley using a counterholder, and loosen the tensioner pulley. The timing belt should be placed without forcing it. A loosened tensioner pulley is a prerequisite; you may even remove the crankshaft pulley. After placing the belt and tensioning it, the timing is adjusted, then the screw on the crankshaft pulley (counterholder!) is tightened, etc.
Maybe you should look for a guide, like a "How-To" manual?
Sure, here is the translation of the text from German to English:

"vg"

This is a common abbreviation for "very good" in German. It is often used in online forums and chat rooms.
Herbert.

Hello Herbert,

Thank you very much.
After I encountered the lack of synchronization in the camshaft timing during the very first TDI timing belt replacement, I never loosened the camshaft wheel again afterwards.
The engine is running perfectly, and the dynamic injection timing is correct.
The first time, I even adjusted it using a mechanical stopwatch. (80,000 km later, I measured it with VAG-COM, and it was almost exactly at the average value.)
I don't know the exact position of the camshaft relative to the crankshaft, but as long as there are no knocking sounds, a few (tenths of a?) degrees of adjusted valve timing shouldn't have much of an effect. It's probably a mild camshaft installed.

But regarding that 'problem child,' I've now adjusted the injection timing, and the car is running better.
It also doesn't seem to be working properly; only the VAG program freezes up when you press the accelerator hard.
It slightly vibrates in the higher gears at 1250 RPM, which might be normal. The owner still needs to confirm whether it has full power.
The good news is: the error message 0575 is no longer appearing.
I haven't actively deleted them, and I don't know how VW programmed the control unit, whether the (no longer existing) error automatically clears after x times of turning the ignition on?

I measured the turbo pressure in MWB 11:
900 RPM, 907 mbar, 93.4% duty cycle, and at...
3000 RPM, 1276 mbar.
Is that okay?

Questions:
1. Where is the temperature sensor actually located for the control unit?
There's just some kind of switch (gray) on the oil cooler, and also just something with a switch (blue) on the cylinder head, but no NTC sensor.
'The turbocharger is making a rattling noise, kind of a 'shsh' sound like a tram passing by. When you press the accelerator, the noise increases, even though the engine speed doesn't go up. Any ideas what could be causing the rattling?'

Hello Wolf-Dietmar,

Without knowing which version of VCDS (possibly outdated?) you are using, and without your VCDS license information, we cannot proceed further.
Please contact me via private message.

Best regards, Rainer.