need help 2001 kia sephia running rough

Hi, I have a 2001 kia sephia with a 1.8 4 cyl with a 5 speed. A few days ago it started idiling rough and sputtering while driving; then the check engine light came on. I got the codes and there was 4 (p0300) random or multiple misfire (p0301 p0302 p0303) cylinder 1 2 and 3 misfire detected. The sputtering and rough idle is not all the time and it is at random speeds and rpms. The car has 85k miles on it. The only thing i have done to it tune up wise is plugs and a fuel filter about 10k miles ago. I don't want to start replacing parts i dont need. Any advice on where to begin?

 

I had a 99 vw bug with the same codes and it was the mass airflow sensor. Hope this helps.

 

Thanks. I called a kia dealership and they said the mass airflow sensor has its own code if faulty. I went to get one anyways and they were 85 dollars so i tried a few other things. I put lucas fuel injection cleaner in the tank, new plugs, wires, fuel filter. I checked the fuel pressure and its fine. After all that i drove it and then pulled the plugs and none of them were wet which leads me to believe they are all firing. But it still runs like before. Is there any way to be sure it is the mass airflow sensor? Any other ideas would be appreciated? Thanks Joe

 

One more thing. I just drove it. I backed out the drive and started to go forward. it went a little then nothing. The car seemed like it was still running but the pedal had no response and seemed harder to push. I pushed the clutch in and revved it up then it went again. does anyone have any ideas. thanks

 

After you did all that work, were you still having the code issues and the sputtering? You never clarified that. For all we know, you may have fixed your original problem, and now, from tampering under the hood, the throttle linkage somehow got messed up (or a vacuum line came off?).

I'm curious why it backed up okay (again, you said nothing about sputtering), then suddenly acted the way it did trying to go forward. Or does your driveway really slope downhill where you weren't even giving it hardly any gas to back up?

I have no other explanation as to why the gas pedal should feel harder, unless these cars have some electronic or vaccum assist or something to the throttle. If it did, then when engines are ready to die they lose vacuum. Anyone else?

 

Thanks for the reply ecman51. Sorry, Yes i had the code cleared and it came back within 15-30 min of driving. My drive isn't long enough to where i actually let the clutch out all the way so i am still giving it gas. It doesnt run rough all the time. Sometimes it runs fine. Somewhere online that i read said to replace my ignition coils. Does that make sense? IF so is there anyway to tell if they are bad? Cause they arent cheap. Thank you

 

I can't really advise you on this. Maybe one of the certified guys here can offer their 2¢.

Sounds like it could be most anything. Sporadic troubles are the hardest things to figure out. I remember years ago (early 70's ) when the first modern technology came along, you'd be able to hook your car up to say a Sun scope. They would then run the car, maybe put it under load, and watch the oscilliscope pattern of the electrical secondary to see if the wave patterns were correct or if spark was breaking down. Surely you'd think today, that they can trouble shoot in similar fashion. Coils are hard to diagnose when they are behaving normal sometimes, without simulting the condition to where the secondary high-volt current starts breaking down.

Otherwise, I'd say it's just a guessing game, of, could be this, could be that. But I suppose you are now figuring that if you replace the coil pack yorself, it will cost $X. But if you take it to a garage and they diagnose, it will cost $X. Or $X + Y, even. So you are wondering if taking the chance might be worth it. Well, it would only be - if you were right.

 

thanks I think i will try the coils and hope i am right. If not im taking it to the dealership to get a diagnosis done. Ill keep everyone updated.

 

thanks to all who gave advise. I think i finally got it. I replaced the plugs again with ngk plugs like recommended in the book. Then i replaced one of the ignition coils and now it runs.