Hello guys, wanted to summarize here again what I could find on the topic of warm start problem. I have not found the actual cause of my 850TDI yet (unfortunately). Spoken solutions: 1) air in the fuel system (I checked, found nothing – point 6 speaks against) 2) temperature switch change (made – did not bring anything) 3) magnetic switch on the starter defective – starter must be dipped (really?) 4) ECU defective (priced) 5) have read somewhere already, that the OT-Geber (sitting under the ESP on the engine block) does not work properly in the warm state, but it is expensive (80Euro) and Pkt. 5 speaks against it. My experiences, which avoid the problem: 6) push the car – jumps perfectly at 7) briefly start (Motror does not start), then just leave the ignition on AN for about 1 min and again start attempt – usually someone else works an idea – together the problem would have to be circled in and solved, right? (there unless it’s really the ECU – I don’t want to change that for cost reasons) Gruss, Eduard