AVB Chip: Troubleshooting PD Unit Issues

HEY!

I'm new here and I have to bother you with a question right away, hopefully it's not too unqualified!

I once read that there are problems with the 74kW PD engines when they are chipped. Supposedly, diesel fuel can build up in the injectors and cause them to rupture.

Is that correct? I couldn't find anything about it in the forum search.

Wenn es stimmt, gibt es eine Abhilfe? Düsen tauschen? Costs?!?!?

Sure, here's the translation:

'Thank you in advance!'

Does nobody really know anything about it?!

You're giving us less than 2 hours to respond... sorry, the forum isn't constantly monitored!

I haven't heard anything about a failing injector nozzle before. And that issue with diesel backflow shouldn't really occur either.
"Tell me where you got that from."

Yes, sorry! I was a little impatient!

I have this engine and I want to get it chipped! A colleague of mine read something about it from another forum and advised me against it! Unfortunately, I don't know which one! It's probably just that 'I heard from someone who knows someone who...' kind of story!

Hi,

Don't worry so much about the PD elements; instead, focus on your clutch.
According to reports from various forums, at least in the G IV class, it's not particularly reliable – even without a chip.

After the accident, you'll have a different vehicle.
That being said, it's definitely worth considering the clutch.

After the MKB, you have a different vehicle...

According to the vehicle classification table (MKB/PKW), it should be an A4; otherwise, that engine wouldn't have been installed in any other car.

Regards,
Private.

HI!

Thank you for the reply!

Yes, it's an A4 Avant manufactured in September 2003!

I just heard that the diesel is building up in front of the injectors due to the increased amount, and then the injectors are being damaged as a result.
If you haven't heard about it yet, then I'm not too worried!

Hopefully, the clutch will be able to handle the 30 horsepower and 50 Nm of torque! I'm not the type who likes to race at traffic lights! I just want more power, especially on the highway!

Hello,

'Yes, there are statements from so-called 'anti-chip tuning' experts suggesting that extending the injection duration in a common rail system (PD) could create additional pressure spikes of up to 500 bar (PD = approximately 2000 bar + an additional 500 bar), which could cause the PD element to burst.'

That is more likely scaremongering. I am not aware of any exploded PD elements yet.

...just a really silly question...
If I'm right, the camshaft, through its pressure on the piezo element (PD element), causes the pressure increase there. So, if that's correct, how can we achieve 500 bar (which is 25% more pressure)? The pressure generation seems to be a purely mechanical process. The electric system only controls the injector and the opening time can be varied. Does the excess pressure escape through some kind of leak oil line...? Or am I completely wrong now?

@Matthias:

No, you can even be completely right. How is it possible for extending the injection duration to increase the pressure?

Beautiful experts . If I let the grass grow a little longer in the summer, will that also increase the pressure in the hose ?

VW would probably be happy to reach 2,500 bar at all...
That would be at least a preview of the next generation of injection technology!

"...and here it is... introducing the high-performance PD camshaft... that would be something. Let's hope the timing belt can handle it, and then I might actually start worrying about the PD units..."

but the thing about the garden hose... yes!!!

matthiasTDI96 wrote:

...let me ask a really silly question... If I'm correct, the camshaft, through its pressure on the PD element, causes the pressure increase there. So, if that's right, how can 500 bar (which is 25% more pressure) be achieved? The pressure generation is a purely mechanical process. The electric system only controls the injector, and the opening time can be varied. Is the overpressure released through some kind of leak oil line...? Or am I completely wrong now?

Hi everyone,

I agree. In simplified terms, the injection pressure results from the product of the steepness of the injection cam and the engine speed.
If is injected for a longer duration, then a (normally unused) "steeper" section of the injection cam will likely not suddenly come into play - what benefit would such a cam profile have in normal operation?

The only way to increase the injection pressure without making any hardware changes, in my opinion, is by increasing the engine speed and shifting the rev limiter upwards.

If, for example, the increased amount of fuel is still being injected at 5000 rpm instead of almost zero (which would be the normal idle speed?), and if the tuned idle speed is even higher, then significantly higher maximum pressures will occur as soon as you utilize the extended RPM range.
Then, possibly, nozzle bursts could occur...

@MatthiasTDI96:

You can find information about the camshafts here http://shop.all4tdi.de/wareshop.php.
Please note the performance increases: SDI increased to 120 hp, and the 110 kW TDI increased to 225 hp / 450 Nm .

The hardened versions are the plastic-lined loading systems designed to minimize leakage. ...

I find all4tdi to be very knowledgeable, and I believe what he writes!

I would rather have my engine completely rebuilt by all4tdi than just get 200 horsepower from Wendland with a different turbo and modifications to the intake system!

The camshafts in all4tdi engines are for the valves, not for the PD (common rail) injectors.

Regards,

Manuel.

Roger wrote:

@MatthiasTDI96: You can find information about the camshafts here http://shop.all4tdi.de/wareshop.php. Please note the performance increases: SDI with 120 hp, 110 kW TDI increased to 225 hp / 450 Nm . The hardened materials are the plastic-lined loading systems designed to minimize leakage. ...

It would be interesting to get some references from people who had their car modified there, who have used a "standard" dynamometer (like Bosch or ADAC), and who actually drive their cars (not just as showpieces in the garage).