Audi 80 Powerbox: Location & Connector

Hello TDI enthusiasts,
I have an Audi 80 TDI Avant, manufactured in November 1993, with engine number 1Z 0102414.
Which Powerbox module can I use for this?
I've already checked under the engine cover! At the back, there's a round connector with 7 pins (a round connector), } but all the manufacturers (on eBay, etc.) list either 8-pin or 10-pin connectors! } And the connector looks completely different from the pictures. }

Please provide some advice and/or links on this topic.

Okay, here's the translation:

Thank you.
Holger.
AUDI 80 1Z
11/93 (Year)

Hello Holger,
Your motor definitely doesn't have a 10-pin connector.
Only 7 of the 8 pins are connected. I would describe the shape as oval.
The part number on mine is 3A0 973 834.

Best regards, Rudi.

Okay, bitte gib mir den deutschen Text, den du übersetzt haben möchtest.
That's all nonsense. The connector on the very old 1Z models was also eight-pin (with seven used contacts), but it was round (I just found something among my old copies).
I'm not 100% sure, but the ESP likely still uses the potentiometer-based throttle control. This would mean that all the 'normal' power boxes and the 10-cent tuning described in this forum so far would be ruled out.
If anyone can confirm my suspicion, please let me know.

- R -

Rudi is right...
I also have an 80s Avant model from 11/93, and it has the ESP with a potentiometer-based rotary encoder. There are eight pins on the ESP connector, which is perfectly round. Seven of them are used.

@Rudi:
I've read something about this in another thread, but I don't quite understand it: Why doesn't the 10-cent tuning work with this type of RWG (Rotary Vane Generator)? Isn't it also just changing a reference value that makes the pump believe it's injecting a different amount of fuel?

Hi Edward,
In principle, it should work (and it might even be simpler than with the newer models, since the power supply provides DC voltage).

The following questions need to be clarified:
- Resistance of the potentiometer.
- Internal resistance of the control unit.
- Is the control signal proportional or inversely proportional to the injection quantity?

If Ri_STG is significantly larger than R_POT, and the signal is proportional to the amount, then a series resistor would be in the range of 20% of Ri_STG.
(a bypass switch for activation or for the power-on test) is the solution.
Under different initial conditions, one would need to use amplifiers and/or impedance converters.


Best regards, Rudi.

@Rudi:
It also works with the 'older' RWG models: I connected a switchable resistor (480 Ohm potentiometer) in series with the two antiparallel diodes, and now I have a resistance of approximately 220 Ohms set on the potentiometer. You can notice a slight change when it's switched on in idle, but I haven't experienced any tendency for the engine to stall at low RPM.

This is just for all 1Z riders with potentiometer-based roll-out gauges (RWG).