2004 Kia Optima Car start but it not running

SOUNDS LIKE THE THROTTLE POSITION SENSOR ! BUT USE YOUR WARRANTY! TAKE IT TO YOUR DEALER&GET THEM BY THE THROAT IF NESSARY, & MAKE THEM FIX THE PROBLEM. YOU HAVE A 100000 MI. WARRANTY ON THE POWERTRAIN EVEN IF YOU BOUGHT IT USED ! KEEP IN TOUCH!

I agree that you should take back to a dealer for warranty. My Kia Optima had similar symproms at 101,000 mi. And it turned out the electric fuel pump harness had melted creating an open in the circuit. Sometimes it would run and others not. Also, just for fun, check the National Highway Transportation Safety Administration website. Ther are two other situations of burned up harnesses (inside the fuel tank), but no recall

I have a 2004 Kia Optima also and that same thing happened to me a few weeks ago, I took it to my local dealership and i1t turns out I had done terrible maintence checkups on the car so my car would start but then die two seconds later because I had a bad transmission. Luckily, Big jobs like that are covered by Kia since im only at 72,500 Miles, If you have that warranty please take your car in as often as you can, use that warranty if the problem is huge you never have to pay a dime because once your out of the 100,000 Range and you let it continue lol trust me it will be costly think about it from a new transmission$1500 Atleast! A new Engine LOL forget about it. Hopefully you take better care of your car than I did I got i1t fixed didnt co1st me a Dime and just had my check engine light come on a few days after I got i1t checked and just got it back today turns out i1t was only a bad Vaccum Valve so they did that normally wouldve cost some money to fix i51t but that was there problem shouldve fixed it last time. So Please before you buy a car get that Warranty i1ts well worth the money. :) Goodluck