Vague guidelines for setting up PD elements

Hello,

After discovering that my engine's injection timing was set 3° KW too late from the factory, I also checked the "preload" of the common rail injectors yesterday (also as preparation for a corresponding technical article).

According to the "now I'll do it myself" guide for the Polo 9N (engines ATD, AXR and the corresponding 3-cylinder engines), the PDE injectors are rotated into their respective positions, and the locking nut of the adjustment screw is loosened.
Then you turn the adjustment screw as far as it will go until you feel a noticeable resistance = PDE set to its maximum value.
Then rotate it back by another 225 degrees, tighten the lock nut – and you're done.
(The same information can also be found in a VAG manual for the AVB/AVF/AWX engine.)

My pressure differentials were all set a bit too tight: it was only possible to turn them in by slightly more than half a rotation before you could feel the "beginning of contact."

I then turned it a little further each time (-> "noticeable resistance"), hoping to eventually reach 225°, but before I could turn another half plus an eighth of a revolution, my intuition screamed "STOP, or you might damage the PDE."

I then adjusted the setting screws by turning them out by the specified 225°, based on what I perceived to be a very clear resistance, and now all 4 PDEs are set approximately 20° "looser" than they were from the factory.

On the one hand, I think that I haven't yet reached the force required when tightening the screws, which is necessary to build up the injection pressure. On the other hand, during adjustment, the pump pistons are not pressed against a fluid cushion, but against the bottom of the high-pressure chamber.

Does anyone know what amount of force or approximate torque the adjustment screw on a PDE can withstand before it sustains damage?
That would be very helpful for the article.

When the official specification states "up to a significant resistance," I imagine a technician in a closet-sized space using a 6mm Allen wrench and achieving 40 Nm or even more before he would describe it as "significant resistance."

I think it's really impressive that you stick with something until it's absolutely perfect.
(This is a compliment for your ambition.)

I can also imagine that there might be occasional imperfections during the assembly of the new engines, as they are assembled by hand in Hungary. And, as we know, mistakes can happen when people are tightening screws.

Perhaps the new engines are intentionally configured in a certain way, for whatever reason.
Doch dann müsste ja jeder PD nach den ersten ZRW einen tick besser gehen.
Has anyone had this experience?

Hi,

According to Ulf's reports and those in the Ibi forum, a different suspicion is slowly emerging.

What if there's a deliberate intention behind it?

The heavier cars, packed with comfort features, receive engines that are either better suited to handling the extra weight or have been tuned for slightly more power, while the base models sit at the other end of the spectrum (i.e., they operate exactly within the specified performance limits).

Ultimately, they offer the same performance, and no one who bought a more expensive car complains that it performs worse than the cheaper base model.

Best regards,

Jan.

Jan6K wrote:

The heavier cars, packed with comfort features, receive engines that are either better suited to handling the extra weight or have been tuned for slightly more power, while the base models sit at the other end of the spectrum (i.e., they operate exactly within the specified performance limits).

I can confirm this at least for the Sharan model range. Only selected engines are used in those vehicles, and all of them have a tendency to perform above expectations.

Jan6K wrote:

The heavier cars, packed with comfort features, get engines that are either better suited for higher fuel consumption or have slightly more aggressive tuning, while the base models are at the other end of the scale (i.e., precisely tuned to meet the standard performance requirements). Im Ergebnis haben sie die gleichen Fahrleistungen, und niemand, der ein teureres Auto gekauft hat, meckert, dass das schlechter geht als das billigere Basismodell.

Hi Jan,

The basic idea is simple, but in my case, the ~2 horsepower loss due to the incorrectly set nitrous oxide system would have been offset by a weight reduction of just 20 kilograms.

Regarding the performance difference compared to the Ibis models with "DZR-measured" power output (averaging a little over 140 horsepower), I haven't found a concrete explanation yet (and I'm also skeptical about the break-in period: according to the DZR, practically nothing changed in my car between 450 and 1140 km, so I have little hope that there will be much improvement).

It would be useful to compare the data logs from these vehicles: fuel injection quantity, injection start (or, in the case of common rail systems, "boost start"), and boost pressure.

It would be unfair if the 6L engine had more powerful intake and exhaust components (intake manifolds, exhaust system) that allowed it to produce more power with the same engine control unit and fuel consumption, resulting in a better overall efficiency .

Bertil wrote:

At least for the Sharan model series, I can confirm this. Only selected engines are used there, and all of them are "outliers" in a positive way.

Well, that's...
We're back to the topic of performance tolerances again - I still haven't quite understood how hardware variations in mass-produced motors can lead to up to a 10% increase in power output, considering the (alleged) precision in modern engine manufacturing.
Sure, here are some keywords specifically about PD-TDI:

* **PD-TDI:** This stands for "Piezoelectric Direct Injection Turbo Diesel." It's a type of diesel engine technology that uses piezoelectric injectors to directly inject fuel into the combustion chamber.
* **Piezoelectric injectors:** These are small, highly precise injectors that use piezoelectric crystals to control the injection process. They offer several advantages over traditional solenoid injectors, including:
* **Faster response time:** This allows for more precise control of the injection timing and pressure.
* **Higher injection pressures:** This results in better fuel atomization and combustion efficiency.
* **Reduced emissions:** The improved combustion leads to lower levels of pollutants like NOx and particulate matter.
* **Direct injection:** This means that the fuel is injected directly into the cylinder, rather than into the intake manifold. This allows for more precise control of the air-fuel mixture and results in better performance and efficiency.
* **Turbocharger:** A turbocharger uses exhaust gases to spin a turbine, which then drives a compressor that forces more air into the engine. This increases power output and improves fuel economy.

PD-TDI engines are known for their high performance, low emissions, and good fuel

Hi Ulf,

ulf wrote:

Kannst Du dazu ein paar Stichworte speziell zum PD-TDI sagen?

... unfortunately not.
The statement made earlier also applied to VP engines (PD technology didn't exist back then). However, I don't think much has changed in that regard.

I might be able to get some information about performance tolerances in the field of internal combustion engine manufacturing... let's see.

Hi Ulf,

Quote:

The basic idea is simple, but in my case, the ~2 horsepower loss due to the incorrectly set nitrous oxide system would have been offset by a weight reduction of just 20 kilograms.

On the bright side, your car easily delivers the 130 horsepower stated in the documents, even a little more (132, right? Before you correct me). The better-equipped cars are heavier and therefore come with more powerful engines.

"100 kilograms more -> 10 horsepower more; that might actually be the case with the Ibis."

Quote:

It would be unfair if the 6L engine had more powerful intake and exhaust systems (intake manifolds, exhaust) that allowed it to produce more power with the same engine control unit and fuel consumption, resulting in a better overall efficiency.

I'm not sure if the intake paths play such a significant role. In the case of the 6K ASV, the air ducts are also very awkwardly designed because the "mirrored" engine is installed in a car that was originally built for the 1Z/AFN (with the intercooler on the left), so the pipes are long and cross each other, but I can't complain about it. My previous times of 6.25 seconds also indicated more power (although we never calculated it precisely, I don't know the exact weight either - but I will eventually do that and repeat the test), and even based on the GPS-measured top speed, I exceed the factory specifications.

Therefore, the equipment theory sounds quite plausible, but I would also be very interested in knowing where these tolerances might originate (unless we assume intentionality).

Best regards,

Jan.

Hi there,
hello ulf,
Maybe you should apply for a job in quality control at Volkswagen.
or consider a new career path: 'I'm taking a close look at her brand-new car.'

Just as a side note,
or
By the way,
or
For what it's worth,
If the adjustment nut on the PDE is loosened...
A new nut and bolt should always be used.

Sure, here's the translation:

'P.S. If your new approach to the PDE proves useful...'
Then I'll do that too.
Since mine already has 90,000 km on the odometer...
It can't hurt to try.

greetings

PowerSound3L wrote:

If the adjustment nut on the PDE is loosened... sollte immer eine neue mutter, einstellschraube verwendet werden.

Hi,

...and the adjustment screw has become jammed with the mating part of the "ball joint," and the ball pin is stuck with the pump piston... then you might end up having to replace the entire PDE just because you opened the lock nut once?

What exactly could possibly go "wrong"? I'm familiar with those stretch bolts that you just twist and break off, but nuts? In any case, the locking mechanisms on my control levers aren't the self-locking type.

Quote:

P.S.: If your new approach to the PDE yields results, Then I'll do that too. Since mine already has 90,000 km on the odometer... kann ja nicht schaden.

For me, it hasn't made any difference in terms of performance or fuel consumption, as far as I can tell so far.

What if there was intent behind it?

.......das frage ich mich auch manchmal !!
.....a Passat Variant TDI should be significantly slower (not just top speed) due to the extra weight of approximately 250 kg. ..........when I'm driving on the highway behind them, I really have trouble overtaking them (with the accelerator pedal not fully pressed).
...I don't just attribute this to the shorter transmission; I genuinely feel that the 130 hp TDI engines in cars like the Passat Estate and, for example, the A4 Avant are more powerful!!
.......das Gefühl hatte ich aber auch schon beim Vergleich meines 98er Ibiza 6K TDI (AFN 110PS) im Vergleich zum 110PS A4 Avant (BJ 98 ) meines Kumpels.......der ging wie die Hölle, das Mehrgewicht war nicht spürbar !
However, there are also significant performance variations among Ibiza models, so perhaps it's more accurate to consider these differences on a car-by-car or engine-by-engine basis rather than by brand.
Regards,
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Warmly,
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(or simply)
Hi,
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Monchi.

A friend's A3 TDI came with a standard output of 153 horsepower.

Regards,
arne