I had the same problem with my Sorento EX Diesel 2006 and the solution was an easy one. You need to clean a fuel filter that is inside the deposit, as it is the one that is blocked with the fuel impurities and thus not allow a response to sudden acceleration requirements, causing the engine to stall.
Buddy, do not doubt it, it is the solenoid valve, which is next to the radiator's water tank. When this valve is damaged, it makes the vehicle stall and fume.
I took my 2008 Kia Soreto to three shops before one found a dirty throttle body which was breaking the electronic throttle pedal circuit. Got it cleaned and the car even starts better in the morning.