Geschwindigkeitsproblem Passat TDI 81 Kw

Hello, I have the same car.

"Mine doesn't reach the specified 190. After many attempts, it manages 185! Everything has already been checked, but the mass airflow sensor (MAF) is almost at the lower end of its tolerance range. I'll have to replace it sometime."

My consumption is only lower than yours, at 6.0 to 6.2 liters, even though I often accelerate hard (due to the poor performance).

I'm not brave enough to drive at high speeds on the highway for a long time (it already has 130,000 kilometers and is still needed ), but I also think that it might be better then!

Okay, I'm using tires in the size 205/55/16.

Okay, so I used to have this car, it was a rental. With its 110 horsepower, it easily exceeded 200 km/h on the flat roads. The fuel consumption was about 6 liters, but that was with a more aggressive driving style.

Hi,

for the initial boost you need:

When driving north out of Berlin (on the A111), the speed limit is 60 km/h until the city limits. Beyond the city limits, the speed limit is theoretically unlimited (though currently restricted due to roadwork). According to the map, the distance to the next exit (Stolpe/Hohen Neuendorf) is 1.3 km.

Here's what I tried once on the road: Starting from about 80 km/h, I floored the accelerator in 5th gear as I exited the town, and then let the engine rev up. I did this all the way until I reached the 300-meter sign for the exit ramp (where I need to get off) – so, roughly a kilometer of acceleration.

Starting from an initial speed of 80 km/h (approximately 75 mph), with two people on board and in temperatures around 20 degrees Celsius, the Ibiza accelerates to almost 200 km/h (approximately 190 mph) over a distance of just one kilometer.

The maximum speed according to the speedometer is 205-210 (realistically 195-200) - however, it would naturally need a much longer distance to achieve that.

The Ibiza, although weighing 1240 kilograms, is lighter than the Passat, but I'm just mentioning that as a point of comparison.

If you were to use lanes 3 and 4, it might even be faster, but that wasn't the point of the exercise.

Best regards,

Jan.

P.S.: This was a one-time test, and I know myself that it's an environmental disaster.

Hi,

Today, I went to the workshop to have a chip installed.
After the installation, the car produced 85 kW on the dynamometer.
Without a chip, it only has 79 kW.

The mechanic said that something wasn't right with the engine.
I'm getting the car back on Friday.

I'm curious to see what happens.

I will get back to you when I have the car.
I have it again.

donalexo wrote:

I somehow can't understand your approach. You suspect a problem with your car because it's not running as well as it used to and it's consuming too much fuel. Instead of analyzing and fixing the problem, you decide to install a chip to regain sufficient power. Do you really think it makes sense to "spur a lame horse"? If your engine actually has a technical defect, tuning will not fix it. probably not better!!!!

Hello.

I was too lazy to write something similar - but I completely agree with Alex .
Furthermore, +6 kW is a rather meager output for a "typical" chip, and this could offer some avenues for investigation if one has some knowledge of the usual performance gains and characteristic curves of the chip.

Hello again.

On Friday, I picked up the car from the workshop.
Unfortunately, the expert was unable to make any further progress.

I need to schedule a new appointment for troubleshooting.

Furthermore, I read in this forum that...
Carbon buildup in the intake manifold can lead to a loss of power.
as well as potentially leading to increased consumption.

By the way:
I temporarily disabled the AGR (Abgasrückführung system) as a test.
However, I couldn't detect any difference.

To continue troubleshooting, I still need the...
Wiring diagram for the vehicle.
Perhaps one of you can help me.

hturborbo01 wrote:

Furthermore, I read in this forum that even... Carbon buildup in the intake manifold can lead to a loss of power. as well as lead to increased consumption.

Hi.

It's great that you've already found a solution yourself .

Quote:

To continue troubleshooting, I still need the wiring diagram for the car.

As far as I know, purely electrical faults are generally stored in the fault memory. If that memory is empty, a wiring diagram probably won't be of much use to you.

Hello.

'For testing purposes, connect the signal wire of the mass airflow sensor (MAF sensor) to the 5V power line using a diode. This should bring the voltage down to around 4.3 volts. If the engine then starts running, the MAF sensor is likely the problem.'

You shouldn't drive for too long like that, because the car will then accelerate away from its own cloud of exhaust fumes.

But let's get to the testing.

If it's the LMM (likely mass airflow sensor), try cleaning it. If it's completely broken after that...

Hello everyone,

Today, I went to my diesel repair shop again.
They installed new fuel injectors for testing purposes.
built-in.
Since then, the car has been running smoothly again.
The needle lifter was not defective.
And with the chip (add-on), it's absolutely amazing.

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

'In addition, I had also noticed that the car with the...'
old nozzles, at approximately 200 km/h (according to the speedometer), went into emergency mode.
turned on.
With the new nozzles, the problem has disappeared.

Here are a few more troubleshooting tips for you:
I'm looking for a good diesel repair shop that also...
It has a dynamometer.
I'm not talking about Bosch or VAG. They only read the error memory.
And if there's nothing in it, then there's nothing for them either.
defective.

Because with a diagnostic device, you can perform tests on a dynamometer.
find the error most quickly.

If there are no electrical faults (other than a dirty mass airflow sensor).
There are only a few possibilities left.
Sure, please provide the text you would like me to translate from German to English.

Check the engine timing (e.g., timing belt, camshaft, crankshaft).
If these are all okay, then only the compression, injectors, and...
and the performance of the fuel injection pump.

A good diesel repair shop also has a dynamometer for testing fuel injection pumps.

I assume the diesel filter is clean.

Hello,

I'd be interested to know how much TKM (presumably a specific type of material or measurement) the nozzles were made of.
There are various opinions on the topic of life in this forum.
duration of the fuel injectors, but in my opinion, and also...
Experience shows that the fuel injectors in VP-TDI engines are a wear item.
Wear and tear, and the resulting performance losses.
and running culture are subtle. What I'm not quite sure about at the moment is...
Is it clear why the engine went into emergency mode with the old injectors?

Hi Jürgen,

Jürgen wrote:

What I'm not quite able to do right now is... Is it clear why the engine went into emergency mode with the old injectors?

because by installing the new nozzles, you also installed a new NHG (presumably a control unit or sensor), which eliminates a potential source of error for the emergency mode.

Hello Bertil,

but hturborbo wrote that the...
The needle injection pump was not defective! [/quote]

Hi Jürgen,

Jürgen wrote:

Hello Bertil, but hturborbo wrote that the... The needle injection pump was not defective!

I read that too. But how did he determine that the injector nozzle (NHG) wasn't defective? The knocking test is just an indication, but not a definitive sign. Only replacing the injector nozzle (NHG) alone (without the other three nozzles!) can confirm that it was defective.
The statement "...the NHG was not defective, but the nozzles were (replaced as a test)..." is a contradiction! With the four new nozzles, a new NHG is also included, making the statement about a defect in the NHG impossible.
Given that the error aligns with the image of a defective NHG (Network Handling Gateway), and that the device was also replaced, I assume it was defective.

What now?

It started with my car not being able to reach its top speed (190 km/h), and now it's going into "limp mode" at 200 km/h (???). Could there be other problems besides this?

Regarding the faulty nozzles again,

I'm sure the needle valve was working properly.

The car is running in emergency mode with the old injectors AND the chip installed.
jumped.
Without chip tuning, the car did not go into limp mode.
Without the chip, he couldn't have driven it at 210 km/h.

In the meantime, it is also possible to install the turbocharger between...
You can hear whistling sounds at 1000 and 1800 RPM.
I have no performance limitations.
I have to say that I'm going to use the car with the new nozzles.
and chased the chip off the track.

Is that normal?
Many people think so! That would be characteristic of the car.
What do you think?

I am very satisfied with the current performance.

Hi,

Can I sort it again now?

hturborbo01 wrote:

Regarding the faulty nozzles again, I'm sure the needle valve was working properly.

What made you conclude that?

Quote:

The car is running in emergency mode with the old injectors AND the chip installed. jumped. Without chip tuning, the car did not go into limp mode. Without the chip, he couldn't have driven it at 210 km/h.

So, it could also be due to the chip, right?

Quote:

In the meantime, it is also possible to install the turbocharger between... You can hear whistling sounds at 1000 and 1800 RPM. I have no performance limitations. I have to say that I'm going to use the car with the new nozzles. and chased the chip off the track.

And with the new nozzles and the chip, does it no longer go into emergency mode?
Since you only replaced the injectors (including the NHG), but are still using the "old" chip, the suspicion of a defective (or pre-damaged) NHG is obvious.

Quote:

Is that normal? Many people think so! That would be characteristic of the car. What do you think?

Everything sounds normal. Sometimes, when adjusting the VTG (Variable Turbine Geometry), you might hear a whistling sound from the turbocharger.

Quote:

I am very satisfied with the current performance.

What's your problem then?