Durchzugsschwäche mit ASZ | Posts 32+

Okay, so I went to the service center, and they said they can replace the LMM (likely referring to a mass airflow sensor) free of charge. I think I'll go ahead and have them do it.
But of course, everything doesn't happen at the same time or immediately.
So, I would like to ensure quiet nights and I'm going to test the whole thing with a diode tomorrow.
Right now, I have absolutely no idea where to find such a diode or what its specifications are. Everything else is described in the technical article.

I've retested the symptoms, and they are still present.

'When starting in first gear, I consistently get 45-50 liters per 100km (MFA), without exception, even with half throttle. Interestingly, in second gear, it still consumes around 50 liters. These are values I've never seen on my MFA. I even refueled completely and recalculated, and the MFA showed 0.1 liters less than the actual amount.'
I don't see any excessive soot, not even at night in the headlights of the car behind me.

The subjective, somewhat rough vibrations you feel in the 2nd, 3rd, and 4th gears when flooring it, initially below 1500 rpm and then again above 1900 rpm, feel quite sloppy, and the notorious head-bobbing has become significantly less jarring.
Unfortunately, during acceleration from 60 to 120 km/h while leaving the construction site, an older red A4 with a 1.9 TD engine and 110 horsepower pulls away from me, and I don't believe that's possible even if it has a performance chip.

I would appreciate information about the diode, and I'm also open to other suggestions in case the problem might be something else.

Calvin wrote:

So, I would like to ensure quiet nights and I'm going to test the whole thing with a diode tomorrow. Now, I have absolutely no idea where I can find such a diode and what its specifications are. Everything else is described in the technical article.

LMM-Fachartikel wrote:

or try to simulate such a (LMM). This can be achieved with the help of a common diode (e.g., 1N4148)

.
"You'd find something like this in every poorly organized electronics store; the specifications are practically irrelevant for this kind of application."
Thousands of other types like 1N 4001... 400x, etc. (ordinary silicon diodes for rectifier purposes, etc.) will also do it - if your engine computer doesn't react negatively to the fake -> resulting in strange engine behavior, a check engine light, etc.

Quote:

When starting in 1st gear, it always consumes 45-50 liters per 100km (MFA), without exception, at half throttle.

Interestingly, in 2nd gear, it also consumes a whopping 50 liters. These are values that I have never seen in my MFA. }
I can't explain that right now.

But let him run it in 6th gear with full throttle a few times, from approximately 1700 to 2200 rpm, and report the highest instantaneous fuel consumption for each run. This will provide a more reliable comparison.
Mine shows a reading up to 13.9, with the 6th gear being the cruising gear (4000 rpm at 240 km/h).

If your 6th gear is shorter, your maximum fuel consumption should theoretically only be higher in the same proportion.

I just checked, and GKB is ERF and reaches 2000 rpm in 6th gear. According to the climate control system, its speed is 113 km/h.
I will do the acceleration test later and post the results. If it works with and without the diode, I'm still missing the right tool .

Is your speedometer showing 120 km/h at 2000 RPM, or is that the actual speed? What kind of transmission is that?

Calvin wrote:

Are you getting 120 km/h at 2000 RPM according to the speedometer, or is that the actual speed? What kind of transmission is that?!

with 195/55 R 15 tires - compatible with FSM transmission.

I have 205/R16 tires on it.
I can't seem to find 'fsm gearboxes' in the table?!

@Calvin:

Forget the climate control's speed display. I compared it to a GPS, and it's way off on my Golf. The translation of the signals can only be roughly adjusted to match the overall transmission ratio. It works better in some cars and worse in others. It's only intended for internal control purposes, and it's sufficient for that.

The speedometer in my car is off by a relatively predictable 5 km/h, while the deviation of the CT (cycle timer) is non-linear. Therefore, it's better to rely on the speedometer. It's also safer for driving .

What kind of tools do you need for the LMM connector?

Calvin wrote:

I can't seem to find "fsm getriebe" in the table anywhere!

It appears to be younger than the table.

For those who might be interested, here are the speed ranges at 4000 rpm with 195/55 R 15 tires, in 1st/2nd gear.../6th gear:

39 / 71 / 111 / 162 / 201 / 240.

ulf wrote:

Calvin wrote: I can't seem to find "fsm getriebe" anywhere in the table!! It appears to be younger than the table. For those who might be interested, here are the speed ranges at 4000 rpm with 195/55 R 15 tires, in 1st/2nd gear.../6th gear: 39 / 71 / 111 / 162 / 201 / 240.

I'm interested because I happened to come across the translations while looking into something else.
At what gear and engine speed is the maximum speed specified in the vehicle's documentation actually reached?
For my Golf 4 with the ASZ/ERF engine, this should happen around 3600/4400 RPM (6th/5th gear), assuming I've calculated the rolling circumference of the tire correctly (is there a way to estimate the "squish" of the tire?).
I always thought that the maximum speed would be reached at Pmax, which is 4000/min...

Unfortunately, according to http://www.dieselschrauber.de/GKB.html, the ASZ also had a gearbox (e.g., the ERG) that reached approximately 4000 RPM at 205 km/h...

joegolf wrote:

At which gear and engine speed is the maximum speed specified in the vehicle registration document actually reached?

I'm not a speed demon, so I can't provide "official" results (flat surface, no wind, etc.). Theoretically, my 5th gear should be my top gear, resulting in a speed of 206 km/h at 4100 rpm.

Quote:

In my Golf4 with the ASZ/ERF engine, this should be the case at approximately 3600/4400 RPM (6th/5th gear), assuming I have correctly calculated the rolling circumference of the wheel (is there a way to estimate the "squish" of the tire?).

Yes, regarding the speed calculations in the DZR (presumably referring to a specific document or system).
One can roughly estimate a loss of about 3% compared to the calculated outer perimeter.

Quote:

I always thought that the maximum speed would be reached at Pmax, which is 4000/min...

As far as I know... According to your calculation, your gear ratios would be exactly "symmetrically adjacent" to this setting, which, in my opinion, would be quite a poor design.
Have you taken into account the "custom gear ratio" for gears 5 and 6?

I used this formula:

v = (n x U x 0.06) / (ü1 x ü2 x 1000)

v: Speed in [km/h]
n: Motor speed in [revolutions per minute].
U: Tire rolling circumference in [mm] (see table).
Translation of the differential.
Sure, here is the translation of the German text into English:

"ü2: Translation of the selected route"

The specified outer diameter is 1929mm.
At 4000 RPM, the formula yields:
v = 463 / (u1 * u2) [km/h]

ERF values (in the 5th and 6th positions): ü1 = 68/26 = 2.615, ü2 (6th position) = 35/43 = 0.814, ü2 (5th position) = 39/40 = 0.975.
So, that's it:
v(6.) = 463 / (2.615 x 0.814) = 217.5 km/h
v(5.) = 463 / (2.615 x 0.975) = 181.6 km/h

"For ERG, the following applies:"
v(6.) = 463 / (62/20 * 34/45) = 197.7 km/h

The ERF values might be correct because at 6th gear, with an engine speed of approximately 2000 RPM, the speedometer indicates a speed of around 115 km/h. At 4000 RPM, the speedometer shows around 230 km/h, minus a certain tolerance.

I have never tested Vmax .

joegolf wrote:

I used this formula: v = (n x U x 0.06) / (ü1 x ü2 x 1000) Bitte gib mir den deutschen Text, den du übersetzt haben möchtest. The specified outer diameter is 1929mm. At 4000/min, the formula yields:. . .

What's the point of all this effort?
The DZR also displays the speed in field D13, provided that the corresponding data is entered in fields D4 to D10.

(Okay, the rpm field isn't highlighted in yellow... but it still works.)

ulf wrote:

What's the point of all this effort?

Okay, why keep it simple when you can make it complicated.

Okay, the calculated values for the 5th gear on the ERF are also correct. At 2000 RPM, I reach approximately 95 km/h.
Looking at a typical power curve graph, the auxiliary system (ASZ) produces about 5% less power at 3600 and 4400 RPM compared to 4000 RPM. Ideally, this would only reduce the maximum top speed by about 1-2%.

The situation becomes interesting when the torque curve in the highest (but also other) gears is compared. Differences in torque at the wheel of 10% between DRW/ERG-ASZ and ERF/...-ASZ systems are, after all, not insignificant.
Alternatively, when comparing acceleration, a first gear that is approximately 10% shorter makes starting easier.

@all Golf4-ASZ drivers:

What transmission codes do you have?

@joegolf:

ERF.

@Calvin:

What do you need a tool for at the LMM connector?

To replace it, I need to loosen a six-sided screw with a hole in the middle.

@joegolf:

He has ERF.

6th gear, 115 km/h according to the speedometer, at 2000 RPM.

@ulf:

I tested how much fuel it consumes in 6th gear, from 1700 to 22 RPM. It consumed 14.8 liters, and no more would go in.
It's frustrating again because this is a value that I think is normal, as it always appears when accelerating on the highway and settles at 13.7 liters with full throttle.

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

'Another question:'

Should I be able to reach my maximum speed even with a potentially faulty mass airflow sensor (MAF)? I'm going to test that now when I go to the airport.

@Calvin:

You only need to connect the diode to the connector leading to the mass airflow sensor (MAF). It doesn't need to be removed for this. By the way, it's a 5-pin connector with a hole.

Yes, but I was possibly going to try swapping the LMM , as I have connections to a helpful person.
The thing about the diode works without >>5<< Kant, as you already said .