I have had an on going problem since May with my 2004 Sedona 2.9 diesel auto loosing power and then cutting out. First time it happened I pulled over, engine still running at idle speed then it stopped, turned off ignition removed key, replaced key and it started, as I do everytiome it happens now.Carried on my journey, another 5 miles ishand on way back home did the same again. Driving round town it has never done it, journies on A roads its never done it, only when on mways or on roads travelling at constant speeds above 70mph. Can travel varying distances before engine cuts out, had different levels of fuel in tank, different weather conditions. Had ECU checked and showing no faults. Service done just after problem started, relaced fuel sender unit in tank as one fitted did not have filter on it, replaced brake pedal switch, had fuel filter checked and is clean, last time it was in garage fuel filter checked again and fuel lines blown out, no debris or dirt. It has now started to fail to start and I have to prime system using prime pump next to filter. Replace fuel cap with emergency rubber one with big hole drilled in it to prevent tank from creating vacuum, still not cured. I dont take car to Kia agent as I dont like stoneacre, so rang and spoke to next nearest and they suggested doing what we have already done, the garage I use I have been using for a lot of years but they are baffled too. Hope you havent got bored reading this but tried to give as much info as possible.