Rough idle and acceleration

2012 KIA OPTIMA
67,000 MILES • 2.3L • 4 CYL • FWD • AUTOMATIC
Avatar
MARKIEP500
  • MEMBER
  • 1 POST
Car hesitates/sputters when trying to accelerate at moderate speed (around 60MPH). Car will then idle very rough (almost stall) when I pull over and check engine light will come on. Turning the car off will eliminate the light, and the car will idle normal. Issue repeats itself when I get up to speed again. 60-65MPH seems to be the trouble-spot.
Nov 17, 2014 at 9:36 AM
Advertisement
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,854 POSTS
It sounds like the engine is misfiring. This can be caused by low compression or bad spark plugs. Here are a few guides that we help us find the problem and fix it.

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

and

https://www.2carpros.com/articles/how-to-change-spark-plugs

and

https://www.2carpros.com/articles/how-to-test-engine-compression

We should also read the codes to see what come up like a cylinder misfire code which will lets us know which cylinder is having the problem.

Please let us know what happens and upload pictures or videos of the problem.

Cheers, Ken

Sep 27, 2017 at 3:48 PM
Avatar
AMS14
  • MEMBER
  • 1 POST
Rough idle only happens when I fill up my gas tank. It will last for a short period of time but once I turn off and restart again it runs fine until I fill up again. Also notice when this happens it struggles to get my speed up acts as if I'm running out of gas.
Sep 27, 2017 at 3:48 PM (Merged)
Advertisement
Avatar
HMAC300
  • CERTIFIED EXPERT
  • 48,601 POSTS
scan for codes and check fuel pressure with a gauge autoparts rent them
Sep 27, 2017 at 3:48 PM (Merged)
Avatar
RODNEY E WILLIAMS
  • MEMBER
  • 1 POST
My car started exhibiting a problem about fifteen minutes of running so it had plenty of time to warm up to normal running temperature. It started when I had accelerated from a stop. I noticed that the power was reduced but it wasn't sputtering. It seemed though to confuse the transmission, it was hesitating between gears. When I had to stop at a traffic signal it felt as though the car was going to stall but did not. It drove fine, no sputtering or hesitating although it was shifting through the gears with a lag. When I pulled into my driveway and put it in park, the idle was improved although the engine had a slight shake. Restarting it didn't change the symptoms. I changed the plugs but no change. I pulled the coil packs and ohm'ed them and both read the same. I know the coil packs can read good but have a problem when voltage is applied. I am retired and on a limited budget so I do not want to throw money at it. It appears to me to be something in the electrical system, is there a way to check voltage to the coil packs and back track from there? Or has anyone had a similar problem that might lead me to a fix?
Sep 27, 2017 at 3:48 PM (Merged)
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,854 POSTS
Hello,

I would start by checking the car for trouble codes. Here is a guide that will help you get the codes.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please let us know what happens.

Cheers, Ken
Sep 27, 2017 at 3:48 PM (Merged)
Avatar
SCOTTIEYEE
  • MEMBER
  • 1 POST
why is my kia optima 2002 idle very rough after washing my engine out
Sep 27, 2017 at 3:48 PM (Merged)
Avatar
KHLOW2008
  • CERTIFIED EXPERT
  • 41,814 POSTS
Check the spark plugs for presence of water. It would misfire if water is present.
Sep 27, 2017 at 3:48 PM (Merged)