TDI Shudder: Troubleshooting & Solutions

My Audi 80 Avant TDI from 1994, with 66 kW and 185,000 km, has been in my possession for 3 weeks. It vibrates at approximately 1800-2000 RPM. I have replaced the timing belt, radiator, and thermostat. The Audi workshop has read the error memory twice without finding any results. Cleaning the air mass sensor (MAF) grid, which was dirty, temporarily resolved the problem, but it is now reappearing gradually after 500 km. The MAF sensor seems to be the original one, with a stamp indicating 1994. The workshop's suggestions are to replace the fuel injection pump or injectors. I suspect the MAF sensor. My fuel consumption is 6.5-6.7 liters per 100 km with moderate driving. Is this within the normal range?
Thank you for the answers.
georg

Okay, one more thing about the jerking – it only happens under partial load. If I give it full throttle or completely release the gas, there's no more jerking.

.... Search function...

Enter your make and model, then the word "jerking," and click "search for all words," and you'll be overwhelmed with helpful tips/information and colleagues who have had/are having the same problem.

If, by any chance, it's a 1Z, then have fun.

IT IS A 1Z.
.................I think that option was only available during that year of production.
Georg.

For consumption:

Oops, I think "moderate" is a bit too strong.

My G3 variant (12/95, 1Z engine, 155,000 km, roadworthy, 1400 kg, no air conditioning) constantly requires me to drive at 180 km/h before it reaches a fuel consumption of 6.0 - 6.2 liters.

As soon as I drive "moderately" (in the city and on the highway, at 140 km/h), it goes below 5.8 [liters per 100 km].

m

Did it already jerk before the timing chain replacement? Because the jerking can also be caused by a pump that is 'too late' in its static position! That's what happened to me! However, no Bosch service center or workshop could confirm it, or they didn't notice it. Today, I loosened the camshaft wheel myself and rotated it about 1mm earlier >> The engine no longer jerks during sudden load changes, my vibrations between 1900 RPM and 2300 RPM are gone, and I hope my 'misfires at idle' are also gone!


Greetings.
Andi.

Okay, if cleaning it helped, then I would recommend replacing the mass airflow sensor.

hello
Replacing the mass airflow sensor was the key to solving the problem!
Now, it vibrates 90% less.
I'll also let you know what the consumption was.

'Looking for a solution - the radiator fan is running constantly. I replaced the thermostat switch, but it's still running. I pulled both relays in the fuse box, but it's still running. I checked the wiring diagram: there's another relay in the dashboard... Currently, the fan is disconnected from the resistor plate... Drove on the highway today - no problem with the outside temperatures.'

I will post a new update when I have more information.

georg