2006 Kia Optima trouble at fuel up

kia
optima

#1

My 2006 Kia Optima has been great and still runs great after 153000 miles. It is the 6 cylinder model EX.

The problem I have happens when I fuel the car. Every time I open the fuel filler cap, and replace it, whether I actually add fuel or not, It is hard to start and “stumbles” for a while…about 30 seconds…before smoothing out and running at the normal idle speed of 750 rpm. I have to hold the accelerator down a little to give it enough fuel to run until it finally begins to idle smoothly. If I don’t, engine speed drops to less than 500 rpm and it stalls out. Any ideas?