AGR to ASV Conversion: Turbo Boost Issues?

First of all, a hello to everyone here.
I've already searched the forum extensively, but I'm now registering because I haven't found an answer to my problem.
My A3, a 1997 TDI model with 90 horsepower and manual transmission, with its aging engine having 247,000 km, needs a new engine.
Since the effort involved in installing a PD engine with all the necessary modifications and TÜV (German technical inspection) approval seemed too significant, I decided, after doing some research, to opt for a 110 HP engine. According to a motor rebuilder in Cologne, this engine can be installed without major problems.
Okay, so it goes... After a long search, I finally found an ASV engine with 67,000 kilometers for a reasonable price. (The engine includes the turbocharger, but not the wiring harness or engine control unit.)
Last Saturday was the big day, and we finally installed the engine.
We left the cable harness in place, and we already noticed a few things during the installation.
It started with the catalytic converter... The flange obviously didn't fit, and everyone just wanted to sell me the entire assembly, including the catalytic converter. After overcoming that hurdle and solving a few other problems, I continued...

The engine starts and runs, but logically, the turbocharger is not being activated.
Naturally, the turbocharger pressure only builds up later and is at 0.8 - 0.9 bar.
During testing, we manually applied vacuum to the can, and then we observed that boost pressure was generated, and it also came out of the 'rpm limiter' (or 'rev limiter').
The functionality would be okay, but the regulation/system/process is questionable.

What I didn't know until then (and what caused me a few gray hairs).
The pressure sensor on the turbocharger is not regulated by overpressure (like in the EGR system) but by underpressure. (Now you're probably thinking... yes, of course, we know that... But I didn't until now ).
I have another car with a 3.0 V6 gasoline engine that has a Garrett T4 turbocharger with a 70mm compressor, and I only know pressure regulators with pressure control .

Okay, the information from the helpful engine seller was absolutely great, and a heartfelt thank you.
Okay, so the engine is now installed, and now the question is...
It's clear that I need to replace the magnetic solenoid valve (on the right side of the mold), and it's also clear that I need a vacuum line and a ball to store the vacuum. But do I also need the control unit, etc.? How does the control unit receive the pressure information, etc.?
What else do I need to change?
I know this is going to be quite extensive, but I'm grateful for any advice.
If you happen to have the part numbers as well, that would be great.
If you need any further information or data, please just ask.

Have a nice weekend...

Andreas.

Alpine wrote:

First of all, a hello to everyone here. What I didn't know until then (and what caused me a few gray hairs). The pressure sensor on the turbocharger is not regulated by overpressure (like with the EGR system), but by underpressure. (Now you're probably thinking, "Yes, of course, we know that..." But I didn't until now.) I know this is going to be quite extensive, but I'm grateful for any tips. If you happen to have the part numbers as well, that would be great. If you need any further information or data, please just ask. Andreas

Did the previous engine have a wastegate turbocharger, while the current one has a variable geometry turbocharger (VTG)?

Because I thought all chargers were pulled in by vacuum!

Hi,

The AGR (Abgasrückführung) system uses a wastegate turbocharger, and as far as I know, all of them are controlled with overpressure.

Hi,

Wastegate turbochargers are controlled by overpressure, while VTG turbochargers are controlled by underpressure.

I'm afraid you'll likely need a new engine control unit, unless you can design a converter that translates the control signals from the AGR control unit, which are intended for the wastegate turbocharger, into signals that can be used by the VTG turbocharger.

"However, I don't think it will work, because the entire characteristic is different (a VTG compressor already reaches its maximum pressure much earlier)."

Best regards,

Jan.

Hello Jan, thank you for the reply.
I was already thinking about the control unit, but what else do I need?
Can I use any control unit from a 110? Are they all the same (e.g., AFN to ASV)? They should be, right?

Hi,

I'm not entirely sure, but the transition from AFN to ASV is quite significant, for example, EU2 to EU3. Also, the part numbers have changed from 028... to 038.... I think you'll have the fewest problems with an ASV device.

Best regards,

Jan.

You're probably right. The only question is, where can I get one of those?

Do you have any ideas?

Hello Andreas,
Please provide the part number of your engine control unit (ECU).
It appears to be an MSA15-7 (038 906 018 ??). The battery already has the split connector.
'...but they still have the internal architecture of the...'
old MSA15 (-5), which is also installed in my 1Z (021BF).
I'm currently using an AFN control unit while I'm out and about. This means the hardware is...
Absolutely identical. It just has different software installed.
I haven't tried it with a 018 ECU yet, but there's a good chance it will work with those as well.
'If there are no hardware differences, the performance is not bad. For the engine control unit (ECU), the boost pressure control in both cases (wastegate/variable geometry turbocharger) is a PWM signal, and the corresponding values and limits are defined in the software.'
Perhaps you have a friendly electrician nearby (who is skilled in soldering SMD components).
that mounts the two PLCC EPROM chips. The original software (for both motors).
I would need it; therefore, you can get it from me.

Best regards, Rudi.

That would be great.
The control unit is already loose and damaged from repeated removal and installation...
As I mentioned, this is the original AGR engine component, and the two chips are already socketed.
If you need the part number, I will take it apart again on Monday.
But it has a split power strip... the left side is long, and the right side is short.

Greetings.

Andreas.

Hello Andras,
Your AGR control unit probably has the part number 038 906 018 AH. I quickly checked...
'No 018 data record found for the ASV. All of them are already EDC15 (012xx).'
BUT ... there was a 'compatible' 110 hp version. The AHF! I gave you the right one.
Software attached.
Make sure the file is in 16-bit format before burning it, meaning it should be represented using two...
The building blocks (high byte / low byte) need to be split.

Best regards, Rudi.

Hi,

@Rudi: According to a VAS 5051 printout that I have here, my completely original ASV control unit has the number ...018FB, so it's nothing like ...12xx.

@Andreas: Forget what I said earlier about 028->038; based on Rudi's post, the AGR doesn't seem to fall into that category.

Best regards,

Jan.

Hi Jan,

Okay, I should have written A3 ASV. But it's quite possible that I made a mistake there.
I missed a stall .

In addition, your software is from 07/99 (version 2167).
Andreas' A3 is from 1997 (the AH SW model is from March 1997 - production number 1604; the AJ model is from February 1997 - production number 1610) - it's likely a better fit.

Best regards, Rudi.

Hi Rudi,

Quote:

In addition, your software is from 07/99 (version 2167).

Almost... the production date is 2170, so it's probably a bit newer. The car is a model year 2002.

Best regards,

Jan.

The AGR and ASV are 038 engines!

The 028 engines are the G3 engines (and were sometimes used later in the Passat).

m;

@ Alpine:

I'm keeping my fingers crossed that it works just by adjusting the software.
Do you want to use the wastegate pressure control valve (for overpressure) for the vacuum control? I also find it difficult to estimate how an N75 valve for the VTG turbocharger would behave when connected to the PWM driver stage of the AGR control unit. The ohmic resistance of the valves is certainly different. However, I can still imagine that it might work if the control unit only monitors for a short circuit or an open circuit.

Here's another question about your MSG: Were your chips already socketed, or did you have them socketed as part of the chip tuning process?

Regards,
Alex.

Hello,

First of all, thank you all for your numerous responses...
I'm going to get the remaining components that connect to the VTG charger and then experiment a bit with the control unit.

@Alex: I had my chips reflowered back then as part of a performance optimization process.
@Rudi: A special thank you for the file, which I will play sometime this week!

Greetings.

Andreas.