01 Kia Optima 4 Cylinder Rough Idle And Dies Out

This car has had trouble since the get-go and am considering never buying another Kia again, but since its my only car as of right now, I need it to be running clean and good, which is not the case at the moment.

I have had another big problem with my Kia for almost a week now. Every time I crank her up, it starts fine, but then it has a horrible time idling and staying idle. After ten seconds or so, it dies out and emits a big hiss (sounds like someone is sighing, but worse).

So had a trusted friend mechanic come over and look at it. At first, he thought it could have been a clogged Cat Converter, since I have known for a while that it’s bad and just don’t want to spend a grand on the car since it’s not even worth that much anymore. He tried running a diagnostics to see what codes were popping up, but for some reason the car doesn’t want to give a code.

So my friend did an overall inspection of the car and recommended that maybe a spark plug/wire change could do the trick. It didn’t. We changed it but still had the same problem.

Then he went to the trunk of my car and tested the fuel pump, which then he had a glimmer of hope since he said there was barely any pressure going to the fuel pump. So we got a new fuel pump. Can you guess what happened next? Yep, the car still had the same problem.

Then he went back to the hood and looked it over. He didn’t like what he saw on the CAM sensor, so he did a test on that, too. First he ran the car with it in, and it rough idled and then died. But, interestingly enough, he took it out and the car ran a lot smoother, albeit only a couple of seconds, before it finally decided to quit. But it did run smooth, so our hope was back.

So we went back to Advanced and got a new CAM sensor. Tried it on the engine. Our hope was crushed. Same problem, rough idle, then it chokes out. Then he looked at the wires and noticed they looked pretty bad, and the next time I started it up for him, he said they “exploded”.

He got on his mechanic website to look up the wiring diagrams for the car to try and find the ECU, but he didn’t want to take the car apart to get to it, and it was dark, so we called it a day.

I’m going to try and get AAA to tow it to his Honda Dealership tomorrow so he can get some second opinions on it and have more tools to work with to try and get this beast running. But hopefully it could just be that faulty wiring? Any second opinions would be much appreciated. THANKS.

Have you cleaned the idle air control valve?


Update: It was a mass air flow sensor and 2 ignition coils. Had it fixed in August, now runs.