Hi.
While reading through the threads, a potential solution for my slight jerking at approximately 1250-1300 RPM emerged: disconnecting the speed sensor on the transmission.

Even though this might confirm a faulty flow meter in the process.
'Where exactly is this sensor located? I haven't been able to find it yet. I only found the connector for the reverse light.'
Since my odometer is advancing intermittently (though consistently intermittently), a faulty sensor could also be the cause.
I would have to find it first.
Thank you for your help with the search.
Hermann.