Engine Performance problem
2001 Kia Optima 4 cyl Two Wheel Drive Automatic 750000 miles
I literally have no hair left to pull out anymore. I have been trying to troubleshoot this issue for so long. ANY help would be very useful at this point.
My Kia Optima 2001 2.4L 4 cyl automatic is having an issue where when im driving I am feeling a loss in RPMs or sometimes, am at 4,000-5,000 RPM and am only accelerating to 20 mph, and then it will boost up to the normal speed if I keep giving or give more gas. It doesn't happen all the time, but it seems to be getting worse slowly. No one knows exactly what it is, I have had a lot of work done to this sucker. The CEL is on and reads a lean fuel mixture in bank 1. I had a problem a year and a half ago where my coils went bad causing an awful jerking when driving, and since then, replaced the coils and all my plugs. Wires probably did not get replaced (not sure). My mechanics dont seem to think coils/wires/plugs are the issue. I replaced one O2 sensor last year, and am waiting on a MAF in the mail to replace that (since my mechanic did a check on it, and it was reading an incorrect voltage). I have used seafoam in the gas tank and regularly use Chevron with techron fuel injector cleaner (about twice a year). I am hoping the new MAF fixes it. I also had a few small vacuum leaks fixed, and the PCV valve was replaced. I did also have to replace the crank sensor a couple months ago. I've replaced all my belts, and I am just running out of resources. At 75,000 miles this thing still runs smoothly other then the jerks while driving. Any ideas? I've heard coil packs, wires, plugs, throttle body, tranny slipping, fuel injectors, fuel delivery, MAF, O2 sensors and cat converter clogging as different problems from similar situations. I will gladly pay for help, but first im waiting on this MAF to arrive (since I just dished out another 100 on it).
Thursday, October 8th, 2009 AT 1:04 AM