1.9TDi BLS: Rough Running After ZMS Replacement

At 213,000 km, my dual-mass flywheel (DMF) failed. It twisted by 13 teeth and occasionally made a loud clattering noise. The DMF was completely replaced with a Sachs kit, and the crankshaft seal was also replaced. Since the water pump was leaking, a new timing belt kit was also installed.

The synchronization angle is set to -0.5°.

Since then, the following has been noticeable: The boost pressure at idle is too low, about 130 mbar below the target value. All seals in the charge air system are new, and there is no evidence of leaks. Could the sensor be defective, or is there a reference value for measuring it?

The bigger problem is that the car vibrates slightly when starting, at around 1300 RPM. This is noticeable when you're sitting in the car, but barely perceptible from the outside. This phenomenon can also be observed when the car is stationary with the clutch disengaged.
The values of the PD elements are all okay. Power is present, and consumption is as usual.
It feels like a misfire (in a gasoline engine).

Everything has already been disassembled and checked again.
Gradually, a sense of aimlessness is spreading.

Can problem 1 and problem 2 be related?
I am grateful for any helpful information.


The engine is designed for a Golf 5 Variant.

"Was the Simmerring installed with a tool? Probably yes, otherwise the torsional angle wouldn't be correct."

The ring is fitted with the original tool, but everything else caused problems 15 years ago...

Good evening.


The description of the symptoms suggests a problem with the timing. Are the timing settings 100% accurate, or is it possible that the timing belt is misaligned by a tooth?

When the engine is idling, the voltage from the boost pressure sensor should be between 0.2 and 4.8 volts.

With the engine off, the connector disconnected, and the ignition on, there should be 5 volts present.

Ideally, the signals should be checked using an oscilloscope.

What diagnostic tester do you have?

Best regards,

Michael.

Hi,

Quote:

The synchronization angle is set to -0.5°.

Since your engine only has one camshaft, and the synchronization angle describes the phase difference between the camshaft and the crankshaft, the valve timing is correct.
It is normal for there to be no boost pressure when the engine is idling, as well as any potential difference between the target and actual boost pressure.

Regarding the glitches, further diagnostic measurements are needed at this time. Please refer to the terms of service.

Best regards, Rainer.

Okay, I use VCDS.
The timing belt is correctly positioned, at least according to the alignment tool. To achieve the exact synchronization angle, I had to move it back by 1/4 of a tooth.
Okay, the 5V are present when the ignition is on. The regulation range for the normal pressure is as expected. Alternatively, I would get a replacement sensor to rule out any sensor-related issues.

So, you can easily check the boost pressure sensor. What values should it display when the ignition is on but the engine is off?

Furthermore, it rarely breaks down, unless there's a problem with the plug or wiring.

Sure, here is the translation of the text from German to English:

"LG" is an abbreviation for "Liebe Grüße," which means "Best regards" or "Best wishes" in English.

So... the pressure sensor has been ruled out; it was replaced as a test.
Everything was disassembled again, including the clutch master cylinder, and then reassembled. It has the correct feel, and the friction disc is not warped.

Is it possible to test or rule out a problem with the PD cable harness? However, I must mention that this harness is only 30,000 km old.

PS: The pendulum support and gearbox bracket were also replaced due to available parts, but without success.

Hello,

The power distribution (PD) lines come from the small connector B on the engine control unit (ECU).

Before the switch, the stuttering definitely wasn't happening.

What do the engine mounts look like? Can you rule out any stress or strain here?

Is it possible that your new part is defective? Please contact your supplier regarding complaints and returns of clutch master cylinders (CMCs) from the company with the blue packaging. My distributor strongly recommends a different product due to customer complaints. Of course, your new part doesn't necessarily have to be defective, but if it is, you can try installing and removing it three more times without achieving any improvement.

Have you ever considered using KDataScope? It allows you to significantly narrow down the search radius and exclude potential sources of error.


Best regards,

Michael.

Hello,

I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Have you checked it already?

A wiring harness could also be the cause of the jerking. If the jerking only occurs under partial load, you can rule out the wiring harness.

Best regards, Rainer.

Hello...

Stupid question: Did you use the correct KW marking tool?
There are probably two of them, right?

Was ist los mit dem camshaft wheel? Was happened to the camshaft wheel?
Was ist die Übersetzung von "Zum Ende hin dieses Rad nach Anleitung nachgespannt?" ins Englische?

How do you diagnose a lean condition at idle? -130 mbar at idle... how is that possible?
If he didn't have these symptoms before the ZR change, I would start investigating that.

Best regards.
Manfred.

The crankshaft seal was replaced. The toothed ring was pressed on using a VW-specific tool.
The timing belt was correctly installed and tensioned, and the twist angle shown in the diagnosis is -0.5.
The engine mounts are good, or have been replaced. The shaking between 1000 and 1300 RPM occurs both while driving and when the car is stationary.
LMM und Ladedrucksensor wurden aus anderem Fahrzeug querverbaut. Unsuccessful.

Today, the remaining parts will be removed, and an alternative ZMS (presumably a type of engine management system) will be installed.

...in my opinion, those were 3 valid questions.

Stupid question: Did you use the correct KW marking tool?
There are probably two of them, right?

Was ist los mit dem camshaft wheel? Was happened to the camshaft wheel?
Was ist die Übersetzung von "Zum Ende hin dieses Rad nach Anleitung nachgespannt?" ins Englische?

How do you diagnose a lean condition at idle? -130 mbar at idle... how is that possible?

You haven't addressed any of these questions at all!

I hope you're right about the dual-mass flywheel now... because I had the first dual-mass flywheel replaced in my Golf just a few weeks ago after 451,000 km! It had essentially become a single-mass flywheel because the inner part was so warped that we had to cut the plate off above the screws... And there were no signs of any problems!

SG
Manfred.

So much time has passed since I last worked on it...

Everything that was previously considered has been swapped out or repurposed... but to no avail...

However, I happened to notice that when the engine sputters, it does so even while the car is moving.

During the test drive, I noticed that when the engine is vibrating, the crankshaft speed differs from the camshaft speed. The difference is zero when the engine is running smoothly, but when it's misfiring, the difference can range from 40 to 120 revolutions.

Is there any tolerance for this? Should sensors be replaced based on suspicion?

Thank you for your helpful support.

Du hast den Impulsring neu eingebaut. Lage und Position sind korrekt? Signal kommt sauber an? Measured?

I don't want to sound like I'm lecturing, but if it wasn't working before, then it's almost certainly happened while you were working on it. Do the "mechanical" timing marks align? Check that as well. You had separated all the relevant components. I think it's a waste of time to look for the problem in the boost pressure or air mass range. I'm just assuming that all the connectors are in the right places and that there are no swapped connections.

MotoBarage wrote:

During the test drive, I noticed that when the tester is shaken, the crankshaft speed differs from the camshaft speed. The difference is 0 when the engine is running smoothly, but when it's misfiring, the difference is between 40 and 120 revolutions. Is there any tolerance for this? Are sensors being replaced based on suspicion?

Well, what can you say? Of course, the rotational speeds of the two shafts must be 100% proportional. Anything else would mean that the engine has just detected a timing belt failure.

Okay, so check which of the sensors is providing the correct value and which one isn't. For the faulty ones, you need to investigate whether the problem is with the sensor itself, the mounting, the wiring, the pulse ring, etc. Naturally, the components you've modified during your work should be the initial focus of your investigation.