Hello and greetings to all brave helpers, so, have now renewed the lamda probe and see, the pulsating acceleration is gone! At this point a warm thank you to all who helped me on the right way!!! But unfortunately the speed problem has remained between approx. 4800 rpm and 5500 rpm! After the 5500 rpm, however, it pulls again cleanly up to the limiter. Renewed: Lamda probe, spark plugs, distributor cap, spark plugs, gasoline filter. Dual-Ram works from approx. 4000 rpm and you notice clearly the performance. Question: Ignition cable possibly or ECU? Would I be happy if you could help me with it further. Greetings SAUS