Polo 86c 40 kW, year 1992, 1272 ccm, AAV throttle potentiometer (Solution)

Hi.
I need to replace the throttle body on the vehicle mentioned above.

I 'had' the right part, but the throttle potentiometer failed.
Inside is now a complete, slightly smaller one, probably intended for the 1-liter machine.
Okay, so I have a completely functional one for 1.0 liters and a Monotronik for 1.3 liters with a defective potentiometer.

'In cold weather, it consumes too much fuel... which makes sense because the mixture is too rich, and it can only be adjusted based on the lambda value.'

I suspect that the throttle potentiometer from the 1.0 engine will fit the mechanics of the 1.3 Monotronic system.
Could I now simply measure the resistance value at each throttle position using the original potentiometer, then connect the top part of the potentiometer to the 1.3 Monotronic system and adjust it until I achieve the same resistance values?
Or is that illusorily inaccurate?
Best regards, Frank.

Okay, it's probably just too old a car.
I will mark the current state and then try to rebuild the potentiometer board.
Report on success or failure follows.
Best regards, Frank.

You are repairing the fuel injection system of an AAV engine, but you have parts from an AAU?
hg
Herbert.

It worked quite well as long as it was warm, but now that it's cold, it's not working properly.
and if I happen to have those parts lying around...
The alternative is to spend money, and I'd rather save that money for a different car.
Best regards, Frank.

That's not what I asked. I understand that you want to save money. It might be helpful if you know which parts of which vehicle/engine we are talking about.
Assuming that the throttle body housing with the defective potentiometer comes from the AAV (Auxiliary Air Valve), and the second one comes from the AAU (Auxiliary Air Unit), this can be determined by checking the part number.
The throttle body housings are different, but the potentiometer doesn't have to be.
Let's think about it.
- RLF or Etzold should provide the resistance values for Monotronic in both cases, just like Etzold does for the Audi 80 (94).
- Since the mid-point tap is likely defective, you can still compare the resistance values of both potentiometers.
- Is it even possible to install the potentiometer in different positions relative to the throttle shaft? If so, measure the resistance for specific throttle angles on the intact throttle body. Create a gauge for this. Then you can properly adjust the intact potentiometer on the larger DK housing.
hg
Herbert.

Hi.
I 'think' I've found the root cause of my excessive drinking.
Report to follow after a reasonably accurate consumption assessment.
Best regards.

Hi.
The setting of the throttle potentiometer doesn't really matter.
Roughly center it, reset the control unit, and the values will adjust automatically.
Of course, only within a certain range, but roughly speaking, it's easy to get right.
The current fuel consumption is 8.28 liters per hundred kilometers.
Given my driving style and the oily oxygen sensor, that's acceptable.
The latter will be replaced soon.
Sure, here's the translation:

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

Hi.
A few things have changed.
I swapped the Singlepoint for an equivalent one from Golf, and I also replaced the completely worn-out exhaust tip.
Fuel-efficient driving on country roads and highways: 5.8 liters per 100 kilometers.
In the city, the fuel consumption is between 7 and 7.5 liters per 100 kilometers, depending on the traffic light situation.
Given the currently favorable prices, I'll get the Polo inspected again and have it pass the technical inspection, and I'll continue driving it for now.
Best regards, Frank.

If anyone else is experiencing this issue:


Okay, now the used throttle body has the same problem.
With VCDS, first...
01
then to 04.
and at 000, start.
Now you can easily track the values being output by the throttle potentiometer.
Clear case: irregular display.
The problem is that for the 1-liter machine, you get the throttle body included. Monotronic delivered the goods.
For the 1.3-liter engine, you're paying three times the price, and even then, it's not guaranteed you'll be able to find one.
I have now done the following.
The accelerator pedal is stuck in the middle.
The throttle valve values were read and recorded.
The contact area of a 1-liter throttle valve was compared and found to be identical.
The contact area is the part where the connector plugs in and where the conductive pads or traces are located.
So, I've moved from the 1-liter machine to the 1.3 throttle body unit and attached it.
The VCDS was restarted, and the contact surface was rotated to 7e0601151, resetting the values to the same level.
The Polo is now running smoothly again, without any jerking or faults.
Therefore, it is possible to modify the contact area from the 1-liter machine to the 1.3-liter machine.

PS: This contact surface is not available separately, but only as part of the complete throttle body unit, which costs 650 euros from the dealer.

Best regards, Frank.