Volvo 850 Combi petrol truck jerks when warm

Hello dear ones, once again a question… our moose has been jerking down more times for a year now. ADAC was also necessary several times. There were changed gasoline pump, relays too, but that wasn’t it. JSince the new petrol pump is in it, it seemed better, but now it’s jerking again. Now after a few readings I heard about the coolant temperature sensor and looked at it myself to change or is the bullshit and it can’t be because of it? The problem always occurs after longer driving and only in the lower speed range. Sometimes it starts delayed. Thank you for an answer. Ciao Miena