Reversometer goes crazy and doesn’t start any more

Hallows together, I just got stuck with my omi…Simply the thing went out 🙁 What I noticed is that after I tried to start the particle again….the tachometer went completely crazy…starting didn’t go any more. Sometimes the hood was fixed and looked inside…One of the two purple-coloured relays (I think the petrol pump relay) was very clinking. So sometimes the ADAC called. It was a little tucked around and the relays also pulled. The good man from the ADAC came up with the idea to hit a little bit of fuel….should have been enough, but good… 10 liters for 14 euros, goes still 🙂 But again nothing… he was still a little busy with the electronics and then after we tried to push the car with the inserted gear and after another relay exchange and the new start attempt the engine hit very loudly….before the ADA… C was there, but he still turned quite joyfully… Also the reading of the error codes did not work….there is something wrong…. Do you have an idea?