rough, shaking idle on 1.9 TDI PD 96kW AVF engine

Hey everyone,

I've already read through several threads carefully regarding my problem, but I can't find a definitive answer as to what the issue might be.

Okay, so regarding the problem:

Passat, manufactured in October 2001, purchased privately as a used car two weeks ago.
I already heard it running rough when I started it, but I thought, "Oh well, no problem."
I checked it at home and used the Bosch tester. Two of the PDE (pre-injection devices) showed different values compared to the other two (I believe cylinder 1 was 1.08, cylinder 2 was 0.32, cylinder 3 was -1.62, and cylinder 4 was 0.2.
Since I was already planning to replace the timing belt and water pump, I also had the injectors removed and sent to a Bosch service center. There, it was determined that two could be easily repaired, one would likely need to be internally re-sealed, and the other was scrap (they said it was electrically faulty). I told them to go ahead and do the work, and I was able to pick up the injectors the next day. As the master technician had told me beforehand, I received two repaired injectors (they looked like they had just been wiped down, and the nozzle at the front had been cleaned), one with a new nozzle at the front, and one replacement injector. All the injectors were fitted with new seals. So far, so good. Upon arriving home, I re-oiled the elements on the seals and inserted them into the head. All 4 injectors went in quite tightly and had no play. Therefore, I assume the head is not worn (they were also very difficult to remove). Now, the elements were carefully aligned perpendicularly and tightened with the specified torque. Then, the timing belt and everything related to it was replaced. The swingarm axles were mounted, and the bolts were adjusted and tightened using a dial indicator. So far, so good.
Okay, here's the sobering reality. I get in the car, turn the key, and the engine starts after a few attempts. The problem is the same as before: it SHAKES and JERKS! As soon as you press the pedal even slightly to increase the RPM, it sputters like a kitten.

Now, I am asking for your help.

What else could I do?

I have VAG-COM. Which engine control unit (ECU) data should I read, and under what conditions (engine warm or cold)?
What minimum or maximum values should be entered there?
What other ideas do you have?


Thank you for your help.

Sure, here's the translation:

"Addendum:"

It has an AVF engine with 152,000 kilometers on it.
Engine Control Unit 038 906 019 EP G000 SG 1464.
FGST.NR. ....209300

The injectors that were installed are part number 038 130 073 AN (2 have been refurbished and are back in, but the other 2 have new injector heads, and I don't know what Bosch uses. Apparently, only 550 injector heads are supposed to be installed).

Well, let's see what your opinions are about it.

The wiring harness to the power distribution units was also replaced, but there was no change.

Can you rule out a faulty dual-mass flywheel (DMF) as the cause?

Please log MWB 1 + 13 while stationary and while driving, and then also log 1 + 18 + 23, and post all the data here in the forum.

Thank you for your quick response.
Do I only need to log the data for positions 1 and 13 when driving, or should I also log the data for the other positions?
I've already logged everyone who's present.

I let the engine run for 60 minutes while idling earlier, and I have to say that it seemed to calm down considerably after about 30-40 minutes. It sounds like a diesel engine should. There's no more shaking, jerking, or vibration. It's strange. Let's see what happens when he starts it up again from a cold state.

t4ronne wrote:

Do I now only need to log 1 and 13 when driving, or also the others?

"The others" are actually sufficient when the vehicle is stationary, because that's where the electrical monitoring comes into play. However, a short drive with a full-throttle acceleration in 3rd gear, within the 1500-4300 rpm range, would also be a worthwhile addition.

Here's the link to the log files.

Okay, I'm ready. Please provide the German text you want me to translate.

I hope you can find something useful in this.

Okay, so when it's running and warm, it still works great.

t4ronne wrote:

Here's the link to the log files. Okay, I'm ready. Please provide the German text you want me to translate. I hope you can find something useful in this. Okay, so when it's running and warm, it still works great

. By "at a standstill," I actually meant it used to idle at around 900 rpm:wink:.

The measured amounts of balancing agents (MWB 13), which are 1.8 mg, are still within the tolerance range (+/- 2.8 mg), but are already somewhat noticeable. Perhaps it's related to the different half-new states of the PDE?
Since the compensation amounts don't fluctuate randomly, I can't draw any conclusions about the irregularities from them.

I'll check tomorrow to see if the Klaten device is vibrating again.
If that's the case, I'll log the MWB values using [tool/method].

What could it be if it only vibrates during the warm-up phase and not when it's at operating temperature?


Thank you very much for everything.

t4ronne wrote:

What could it be if it only vibrates during the warm-up phase and not when it reaches operating temperature?

Temperature-dependent vibration damping parameters in the software.

aha???

That means software customization, right?

t4ronne wrote:

aha??? That means software customization, right?

That would be the seemingly logical consequence.
I don't know how practically successful that would be. ... perhaps ask our landlord (Rainer K).

It would be interesting to know why it's stuttering. It shouldn't be due to the software itself, especially if it's the standard software. Then it would occur more frequently.

"Could it be that the previous owner had a chip tuning module installed? Or, did the Bosch service install a combination of 520 and 550 injectors (due to the two rebuilt common rail injectors)?"

If the car stalls with just a slight touch of the accelerator, try temporarily increasing the idle speed using VAG-Com. At the very least, it could be used to mask the symptoms.

I've also been wondering if the Bosch service uses two different combinations of injectors.

"I had already pointed this out to the master craftsman beforehand, and he said, 'We use whatever Bosch provides us.'"

"Well, thanks, I thought so."

And you can almost forget about finding out anything afterwards.

Mine also shakes and vibrates a lot during the warm-up phase.

According to the previous owner, this issue was present from the moment the car was delivered, and the VW workshop was unable to provide a solution.

If the idle speed is increased only slightly, the engine will stop misfiring. The minimum increase can be so small that it might not even be noticeable on the speedometer based on the engine speed.

I therefore suspect the problem lies with the MSG (Message Security Gateway) and not with the actual hardware.

michiglaser wrote:

If the idle speed is increased only slightly, the jerking will disappear. The minimum increase can be so small that you might not even be able to read it on the speedometer based on the engine speed.

Does this actually work with accelerating, and with the adaptation of the idle speed, or only via the accelerator pedal?