1Z geht nicht richtig | Posts 16+

I tested it today: In third gear, with full throttle, it takes 10 seconds to go from 2000 to 4000 RPM (an approximate speed increase from about 50 to 100). That's quite a long time, isn't it?

Where can I find the Nm (Newton-meter) specifications for the DZR (presumably a specific product or component)?

Does anyone have values for a 1Z? Perhaps also for a 35i?

DocSnydor wrote:

So, I tested it today: In third gear, when fully accelerating from 2000 to 4000 RPM, it takes 10 seconds (an approximate speed increase from about 50 to 100). That's quite a long time, isn't it? Where can I find the Nm specifications for the DZR?

Hi.

10 sec does not necessarily have to be excessively long: a slight incline and headwind can significantly extend the time - hence the rollout test, to "eliminate" such errors.

Furthermore, a ship like the Passat, with 90 horsepower, is inherently a bit heavier than the 110 hp Golf 3, whose specifications are included in the download.

You don't need the torque curve for the DZR (Direct Torque Ripple), as it is calculated internally = estimated.
Simply enter your engine values in the yellow column and transfer the calculated Nm values below into the yellow column next to it (using the "Insert values" function or by entering them manually).

@Ulf

It wasn't meant to be taken that seriously...

@DocSyndor

You can find these values in a brochure, your user manual, or your vehicle registration document (Vmax).
"Of course, 10 seconds isn't very conclusive yet; what comes out of the DZR (differential pressure sensor) is what really matters. But still, 10 seconds is quite a long time, even for a car as large as your Passat." It seems like something is really wrong.

Best regards,
Uwe

The Passat doesn't weigh that much more: the registration document states an empty weight of 1267 kg, but because my fuel tank (as always) is quite full, I estimated it to be around 1350 kg. 'I also set the 'unrolling' delay to a 'generous' 0.2, so the final result is 9.2 seconds, which isn't bad considering my target of 10 seconds.'

'But I usually don't rev the engine that high. What's definitely missing is the TDI's famous power 'from low RPMs.' You don't really feel the acceleration. And then there's the severe jerking up to around 1900 RPM, and the rough engine running.' Coincidentally, there's another post by Detlev (?) that describes the same issue, and he immediately replaced the pump.

Is setting up [something] really that expensive? It seems like mine is also into '[/i]' being 'too fat.'

Hi!

Our measured times often do not match the information provided in the brochures. Therefore, due to the potentially very long switching intervals, a significant source of uncertainty is expected when testing the 0-100 km/h acceleration.

Best regards, Uwe

Hey, what's up with you guys?

I'm not questioning the official acceleration figures. The point here was to find a quick solution (or at least, I thought so). And for that, the 0-100 km/h test is sufficiently accurate. In my experience with my vehicles, it has worked quite well so far (within +/- 0.5 seconds). When performing such a test, it's important to shift gears as quickly as possible. The differences are not very significant.

By the way, the tests should not be performed with an empty fuel tank. More like half-full.

And as I mentioned, Doc Snyder's Passat is running quite well. Maybe next time I should buy the 110 after all .

@DocSnydor!

If your pump is running too rich, you're more likely to have more power than less. In Ulf's DZR tests, many people - as you can see from the numerous posts here - are significantly underperforming! You should definitely be able to achieve a time of 9.2 seconds. A time of 10 seconds represents a 10% power reduction, and there's likely something wrong. Unfortunately, I'm at a loss; perhaps other users might have some ideas...

Best regards,
Uwe

'Still, thank you, Uwe.'
But it still has to be related to the fuel injection pump, because otherwise that 10-cent piece wouldn't have any effect...
And that's the jerking (it even jerks all the way down the mountain ).

Okay, for anyone who's interested:

Today, I finally made the decision and took my car to the Bosch service center. I just received a call from them:

The timing belt is twisted and far too tight!!!

It was replaced last year in November by a VW dealership (where I also bought the car). In addition to the belt, the tensioner pulleys were also replaced. It resulted in a hefty bill of approximately 800 DM .

Great! Just now I called the car dealership, and I got a master technician on the line. I told him the story about the Bosch service. He was completely shocked and couldn't believe it (but he remained very polite). He said he wanted to call Bosch service now and investigate the matter. After that, I will receive another call.

Let's see how things unfold, I'll keep you updated on this whole ordeal...

Okay, so, my car was at Bosch again today:

Diagnosis: The turnout mechanism is broken.

A new one would cost €600 plus installation.
Here's a question for you: What would you do?

The car is a 1994 model with 210,000 km on the odometer. It's not selling well because it lacks air conditioning and is a sedan.
Is it worth spending that much money again, and who knows if it will turn out better in the end!?
Please give me some advice on what you would do. I'm really desperate right now...

David.

Hello David,

Is the reduced performance caused by the incorrectly installed timing belt now resolved?
Is it only the stuttering problem that you are still experiencing?
How did the Bosch service determine that the mass flow controller was defective, and was a hysteresis measurement performed?
Have you ever logged the throttle position sensor voltage during bumpy operation, while maintaining a constant throttle position and engine speed?
What about starting difficulties?
If I recall correctly, the ESP failure in Bertil's 1Z was also preceded by some jerking or shaking.

Regarding your question: if the rest of the car is still in good condition, I would definitely get the new ESP system installed. It would be a good idea to replace the water pump and thermostat at the same time.
Take a look at the values of the idle speed control system when the engine is at operating temperature. High differences between individual cylinders indicate wear on the injectors and/or cylinders.

The depreciation of a new car is so significant in the first few years that, in an older car, a lot has to break down before it becomes truly worthless. Also, in addition, you should have the maintenance done at the workshop due to a goodwill arrangement (which is far too expensive).
That's why I'll keep driving my A3 until it completely falls apart.

Best regards, Rainer.

Hello Rainer,

Thank you for your reply. To be honest, I can't say for sure whether it drives better since the timing belt issue. If so, then at most minimally.
VW, at least, offered a free oil change as compensation .

Subject: Starting problems: It starts relatively quickly, but runs unevenly for a few seconds afterwards, although it doesn't stall.

I don't know exactly what the Bosch people did. I think he said that there were 'grooves' inside. I think he had the pump disassembled. And where the grooves would normally be in the metering device, that's where the jerking occurs (currently between 1500 and approximately 2000 RPM).

Idle speed regulation: The largest deviation observed in any cylinder was +0.4 or -0.4.
I recently created the log files, but they are still on my laptop.

A brand new car wouldn't be an option for me; I'd rather get a used car with a warranty. I'm going to visit the VW dealer today (where I bought my Passat back then); maybe he'll give me a good offer.
I would get a replacement pump for €1000, including installation and taxes. However, I'm worried that the next problem will arise: for example, the injectors, which are not unlikely to fail at 200,000 km. Maybe I'll just keep driving like this through the winter and then look for something new in the spring...

David.

Hello,

DocSnydor wrote:

I don't know exactly what the Bosch people did. I think he said that there were "grooves" inside. I think he had the pump disassembled. And where the grooves would be in the turnout mechanism, that's where the jerking would occur (currently between 1500 and approximately 2000 RPM)

.
Hmm, I can't really say, as I haven't completely disassembled an ESP before.

Quote:

Idle speed adjustment: The largest value observed in any cylinder was +0.4 or -0.4

.
Okay.

Quote:

A new car is not an option for me; I would rather buy a used car with a warranty. I'm going to visit the VW dealer today (where I bought my Passat back then); maybe he'll give me a good offer. I would be able to get a replacement pump for €1000, including installation and taxes. However, I'm worried that the next problem will arise: for example, the injectors, which are not unlikely to fail at 200,000 km. Maybe I'll still drive around like this in the winter, without doing anything, and then find something new in the spring...

Okay, it really depends on the condition and overall state of your car. Construction sites are obviously not worth continuing to work on (from my own painful experience, but my old Passat probably had something well over 400,000 km on it).

Best regards, Rainer.

Hello Rainer & everyone else,

I just came back from the VW dealership. They don't have anything suitable for me right now. I recorded the trip there. It was all on country roads, using display group 1. For clarity, I've left it as an Excel table. Whoever wants to, can take a look at them here...

Best regards,
David

Hello,

Are the "jerks" all the lines where the injection amount drops to 0.0 mg/stroke?
It doesn't look like a problem caused by a mechanically defective metering device to me.
The voltage at the control generator reflects the same value.

Before replacing the fuel injection pump, you should check the cables and connectors to the control unit for the fuel quantity regulator for loose connections.
Marten bites in the wiring, broken cable strands? It would only be foolish if the coil of the volume control itself were defective.

Best regards, Rainer.

I read your description again at the very beginning.
If it doesn't bother you too much, there's nothing stopping us from continuing to drive the car like this, is there?
You alone can decide whether a repair is worth it.

Best regards, D.

Another question: What is the likelihood that the mileage reading was incorrect at the time of purchase?

The 0 mg/stroke readings are due to the throttle cutoff: It was a lightly traveled country road, and I repeatedly lowered the engine speed to around 1500 RPM, then accelerated to cause the jerking, which was recorded in the log file. The stuttering always occurred after the '0 mg/R-phase.'

Okay, I've definitely decided not to sell the car, and like Rainer, I want to drive it 'until it falls apart.'
I'll continue driving as I am for now, since the jolting is caused by higher engine speeds, which I'm trying to avoid. What's still surprising to me is that the jerking isn't noticeable/is barely noticeable (in 3rd gear) in the 1st, 2nd, and 3rd gears!
The turnout doesn't care which track you're on.

I'd like to mention again: the 10-cent tuning shows no effect (I'm absolutely sure I installed it correctly). It only starts making a lot of noise (when the resistance is very high, around 200 ohms or more) and the car starts to sputter; before that, you don't notice any effect when you turn it on.

@ D.
I'm quite sure about the mileage:
- Service booklet available.
- I bought it from the VW dealership, which is the same one where it was originally purchased in 1994.
No, they don't do things like that .

But thank you very much for taking the time to think about my problem.