Elysion Engine Misfires

Given the rough running, check engine light, jerking, and power loss, misfires are certainly possible. Has the check engine light flashed? If it has, that would strongly suggest a more severe misfire. The jerking on acceleration points to a potential issue with fuel delivery or ignition timing, both of which can be affected by faulty injectors. Have you had the fault codes read? That would give a clearer idea of which cylinder, or cylinders, are misfiring.

The check engine light hasn't flashed. If it's not the codes, could a defective injection valve or injector explain the combustion misfires?

Yes, a defective injection valve or injector certainly aligns with combustion misfires. A faulty injector can disrupt the proper air/fuel mixture, leading to incomplete combustion and misfires. Given the mileage, it's not entirely unexpected. However, it would be wise to have a workshop confirm the diagnosis and rule out other potential causes. Have you thought about doing that?

Thanks for the advice. I took it to a workshop, and they confirmed a defective injector. The repair cost 515€.