Audi A4 B5 2000 1.6 petrol - It goes out while driving and sometimes it doesn

There is such a problem with my car .... At the beginning, when I bought it, everything was fine. After about half a year, the car stopped starting as if the fuel pump did not turn on (it did not get a signal). I replaced the battery for a long time it was quiet. But now the problems begin again. It goes off while driving. It can go out automatically for about 30 seconds and then it fired itself after a second and so for about 30 seconds while driving. Recently I drove to a roundabout and the loading started, the engine went out .... Trying to start again, he did not want to. It was only after a continuous test that they ignite and extinguish it after about 2 minutes and it was ok until the end of the day. But the next days are already passing and he is either not a "good morning" or if he wants it, it will go out while driving. What are your ideas of what it might be? Sometimes I have the impression that it loses turnover. Please help.
best regards

Check high voltage coil or control module. The elements themselves or the connections on the contacts.

Connecting to the computer shows any errors? Check the shaft position sensor.

After many attempts to find the problem, the car was taken to a mechanic. The first time was a week and he showed no problems. After a month, we detached it again and for the next week during which it was fired every day several times, it did not fire only once. It turned out that it was a cold solder at the computer.