kgm86

Hi

I'm looking for a solution to my rough idle at start up.

Evo 5 stock engine

cming21

Can you smell fuel? Any loose vacuum lines or one that popped off? Boost leak? IACV may need to be cleaned. Do you have any misfires? Did you check the spark plugs? Spark plug coils to see if they are loose or if they are burnt? Do you have any tunes on it or any other mods? We will need a lot more info to diagnose? You could try resetting your ecu. Just a couple things that I have ran across in the past on previous cars I have had. I hope this helps. If you figure it out please let us know. Sorry if I through a lot at you but it will give you a couple things to look at.

Good Luck!

kgm86

Thank you for the info!

I can't smell any fuel under the hood and from my quick looking around I wasn't able to find any vacuum lines loose or broken but i could be wrong. I do have a tune on the car to run 94 octane in Canada but nothing else. The rough idle was there before the tune. It only idles rough on start up. Once its running and I've had it around the block its totally fine. I have noticed the idle drops considerably with AC on though. It does not seem to be missing and i have check spark plugs which look fine (not rich or lean). I read up on the IACV a little and cleaned it out a while ago but it did not seem to improve much. I think there is a proper procedure to resetting the ECU if I remember correctly?