VW: Retrofitting LDA (Local Differential Analyzer)

Attention: This is NOT about a TDI!


In our AAB-T4 van, an ACV turbocharger has been working reliably for 30,000 km.

The engine runs very well; with 102 horsepower, the TDI models are certainly comparable in terms of performance.

Problem: The fuel consumption is too high for me at higher speeds. For example, it consumes about 8 liters at 90 km/h (approximately 2700 RPM), but it uses a whopping 13 liters at 120 km/h (approximately 3500 RPM).
(He still needs those 13 liters per hour even when driving at 90 km/h with a horse trailer attached.)

Now I'm a bit confused about how the fuel consumption depends on the engine speed.

Perhaps this can be counteracted by a boost pressure-dependent control system. I've heard that it might be possible to convert the common rail injection system of the 4-cylinder engine to LDA (Low-Pressure Direct Injection).
That should also work with a 5-cylinder engine.

Where can I find cross-sectional diagrams of the ESPs that show their internal structure, specifically where the LDA (Low-Density Arc) interacts with them?

The fuel injection pump from the Audi 5-cylinder turbo diesel would also fit perfectly in my car, but it's impossible to find one.

Oops!

(1) You're mistaken; the AAB doesn't have a sequential EFI system. It has exactly the opposite: a distributor-type EFI system, just like its 4-cylinder counterparts.

(2) So, what have you done so far? Just put a turbo on and that's it?

"Well then, everything is clear. The turbocharger is nothing more than a huge brake. It consumes power; people say it takes away around 20 horsepower. So the AAB has a whopping 58 horsepower to work with... not much."

Get yourself an ESP (Electronic Stability Program) unit from a JR/JX or similar manufacturer and try to modify the LDA (Lane Departure Assist). You won't be able to tell if it's possible just by looking at an exploded diagram, as those are too general.

(Just 6 more days until it's our turn for the AAB again.)

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

@dieselmartin,
1. Sorry, my mistake, of course it has a distribution ESP!

'So far, I've loosened the fuel flow screw and adjusted the low-load speed. This way, it doesn't produce any black smoke at full load. So, the amount of fuel injected is sufficient for much more than the 0.6 bar that I have set.'

But, as mentioned before, the problem isn't the performance, but rather the consumption.
Therefore, I'm looking for someone who is knowledgeable about the inner workings of Electronic Stability Programs (ESPs).

Visually, the T4Wiki already offers some benefits.

Do you already have a longer 0.68 ratio for the 5th gear?

If it doesn't produce any black smoke at 120 km/h and 3500 RPM (without a trailer), but consumes 13 liters, I wonder where the power is being lost (no black smoke means all of the diesel is being burned).

13 liters = x mg/hub = theoretical power.

@neubaupe: I'm wondering the same thing! :-/

Since injecting more fuel would mean more power and speed, I have a theory I've been thinking about: at higher RPMs, the turbocharger might not be providing enough air under partial load, which is why it might still produce soot without me noticing. Since it quickly reaches the redline when accelerating with full throttle, that could be possible, right?

@dieselmartin: I've been thinking about it for a long time, but since I often drive with a trailer, the shorter one that's currently installed fits perfectly!

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

'Please provide me with a follow-up question.'
I find many pictures online of naturally aspirated ESP engines (VW Golf, T3), but none of the turbo-diesel (TD) version. I would like to familiarize myself with the internals of the ESP engine head and its interaction with the LDA before starting any modifications.
Does anyone have a link, like this one ( http://freenet-homepage.de/t3-welt/esp/index.htm ), where you can see the inside, but of the turbo version? So that you can see how the LDA works!

Are the ESP housings for the 4-cylinder and 5-cylinder engines the same? (It looks like they are!)

THANK YOU!