Stalls at idle

DEVINSMOMMMY

MEMBER
2004 KIA OPTIMA
44,000 MILES

I purchased this car 2 weeks ago. I noticed it was idling high when stopped or in park. My engine light came on for IAV, so I replaced it. Immediately after installed the motor started shaking. It would do okay once I started driving. We idled it up a little higher to keep it from cutting off on me. Within 2 days it got worse and engine light came back on for coil pack so I had that replaced and all new spark plugs. Engine light went off but it made no difference in car. By the next day, when I came to complete stops or sat still, the rpm would drop to just below 1000 and cut off. I had to put in neutral and touch gas pedal slightly to try to get it home. It got worse and started cutting off while I was driving. Under 35mph. Then when I pressed the gas it would try to go and pull back as though it wasn't getting any gas and then cut-off. There is no engine code on it and the place I take it to doesn't know what's wrong. I've read tons of things it could be online but I just can't afford to buy and replace parts that doesn't need replacing. If you know what this is I will be so grateful!
Let me just add. It didn't seem to want to take regular gas. The handle would click like it was full but it was below a quarter tank.I put 93 octane in it last and it took that great but drove the same. Now I am parked completely because it's just not drivable.

1 Reply

KHLOW2008

MECHANIC
41,815 POSTS

Since you just bought the vehicle, you have no inkling of the history and that would mean starting from the basics. Is there any warrantrty on the vehicle?

If the check MIL is not indicating now, it means the engine computer has not detected any fault and by the symptoms you have described, start by checking the mechanical side.

Check the fuel pressure and MAF.
Clean the throttle body and IAC to see if the idling improves.
With such low mileage, there should be nothing wrong with the timing belt but then again we do not know so you might consider checking the timing belt synchronisation.