I just recently started having idle problems with my Evo. What it does is it will do a rev from 1k to 1.5k rpms and then after doing that for 7 seconds or so will go up to 2.1k rpms and sound like it is hitting a rev limiter. The thing is... Ill go on to the next light and it will idle completely normal. I am thinking it could be related to something electrical because I have also had the brake light and battery symbol flash along with dash/gauge lights while driving when this goes. The car also will start hard as if the battery is drained occasionally. But as I've said... Sometimes everything will start and work normally the next time I drive. Battery? Alternator? Something more? Any input would be great.

 

check your IAC. might need to be cleaned

 

Thanks you

Seems as if many others have had the same issue after searching IAC issues. I will check it and go from there!

I do not see how this would affect the different electrical issues I have though...

 

Check your battary terimals/clamps. Make sure they are clean and snug. If they are check your voltage to see if the alternator is charging. When your cluster lights come on it usually means your alt. is not charging.

 

I had some idle problem last month, clean out the IAC and it has been working perfect ever since. It's worth a try.

 

check ur vacuum lines and your maf too.

 

Thanks for the input! Im thinking that the IAC is my first issue and that the electrical thing is a completely different issue ill have to address also.

 

What do you check on the MAF for problems? All visual or what?

 

Do yourself a favor, clean your IAC, MAF and air filter. Reset your ECU and give it a some time to recalibrate. If your still having those problems after a week of driving it around you might need to grab a multimeter and start checking for shorts, etc.