TDI B4: Upgrade GRA (1992)

Hello.
I want to retrofit a GRA (Gas Recirculation System) in my B4 TDI, manufactured in July 1992. I've already tried using the search function, but I haven't found a satisfactory answer. The most important question is whether this is even possible with my TDI .
I would also be very grateful if someone could tell me which pins of the STG (Steuergerät - control unit) the steering column switch should be connected to, and what code is required to unlock it.
I hope you can help me.
Thank you very much, Woli.

Hello, it appears that your control unit is not yet configured for GRA.
The feature was only available on newer models.

Thank you for the answer!
But the phrase "It seems like" makes it sound like you're not entirely sure. Is there a way to verify that?
Best regards, Wolfi.

I'm not 100 percent sure because there's a limit somewhere.
It applies to the 1994 model year IZ. However, I can't say exactly how much earlier it applies.
You can check the wiring diagram to see if there was an integrated starter (IZ) with GRA (glow plug relay) for your vehicle's year of manufacture.
If so, then you can also add it later.

Hello,

I would like to retrofit a GRA (Gas Return Accelerator) in my B4 TDI, manufactured in 7/92. I have already tried using the search function, but I haven't found a satisfactory answer. The most important question is whether this is even possible with my TDI .

Could it be that you have the manufacturing year wrong? Because the B4 model wasn't introduced until August 1993, and that's when the 1Z engine was first used. In the older model, it should be an AAZ engine.

In this case, GRA could only be installed in conjunction with a mechanical vacuum pump.

Okay, I'll check on both of you tomorrow.

Could it be that you have the manufacturing year wrong? Because the B4 model wasn't introduced until August 1993, and that's when the 1Z engine was first used. In the older model, it would have been an AAZ engine.


Well, who's here? FettesBruder, look who's back. Audi also had a B4 model, which was the last Audi 80; after that comes the B5 (A4).

Best regards, WarLord.

Hello,


Could it be that you have the manufacturing year wrong? Because the B4 model wasn't introduced until August 1993, and that's when the 1Z engine was first used. In the older model, it would have been an AAZ engine.

.

The 1Z model was already available in the B4 series starting in June 1992.

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

'MFG' is an abbreviation for 'Mit freundlichen Grüßen,' which means 'Sincerely' or 'Best regards' in English.

Aha!
Then I probably got one of the first 1Z models with the production code 7/92.
I went to the service center today, but no one there really knew whether it would work or not.

Okay, I have something for you:
The Audi 80 IZ automatic can be upgraded with GRA starting from July 1993.
For manual transmission vehicles, starting with chassis number: wauzzz8czra128401.
The 'r' after the 'z' indicates the year of manufacture, with 's' representing 1995, 't' representing 1996, and so on.
After the letter 'a', a larger number is acceptable, and after the letter 'b', it is definitely acceptable.
Are all the ambiguities cleared up?

Thus, you have destroyed my last hope .
I am very grateful for your answer, nonetheless!
Hi, Wolfi.

Hello everyone.
Okay, since I have no other choice, I'm going to build a GRA myself.
(With microprocessor). Actually, that shouldn't be too much of a problem.

I have the following ideas/suggestions/plans:
I will use an original switch for operation.
When the GRA (Gear Ratio Adaption) is activated, the engine speed is kept constant and can also be adjusted using the "+" and "-" buttons. (There's a small issue: a single button press results in a different speed change depending on the selected gear, because the engine speed is being regulated. However, I don't think this should be a problem in everyday use).
When the clutch or brake is engaged, the GRA is deactivated, but it can be reactivated using the RECALL function (which retrieves the stored value).
Furthermore, I would like to switch from the accelerator pedal position sensor to an electronic potentiometer or DA converter using a relay when the GRA (Gas Response Amplifier) is activated. However, I am concerned that the control unit might report a sensor error during the switching time.
I hope you can answer my questions and that you have some suggestions for me.

But I have two more questions: What happens if the GRA is active and I press the accelerator pedal?? And what is the maximum RPM for a TDI when I increase the speed using the "+" button??

Greetings, Wolfi.