Is this normal? My 2011 evo x with 2000 miles, rpm sometime bounce a bit at idle. it is not steady and bounce 100 rpm up and down a little randomly. But when it warm up, it seem tp be more steady

here a video if it, you can see the needle moving.

http://tinypic.com/r/s1t5ef/5

 

Thats the first thing i noticed when i bought my X as well. Other members report the same issue so I don't worry about.

 

It's fine. Do you have your A/C or defroster on?

 

yeh i had it on at first and off in the last half of the video

 

oh okay thanks

 

Anytime something cycles that puts a load on the engine your RPM's will fluctuate while the ECU compensates (A/C, alternator, power steering, etc.).

 

Lil 4 banger ppl,any type of load make the rpm fluctuate. 100rpm is nothing..if it were 500+ then we'd need you to check that pesky vac line

 

it even fluctuate when i am doing nothing. it just slight move up and down a bit, i guess it is normal then

 

It looks like a evo 10 quirk. I could be sitting at idle, not using the brake, fan motor completely off and my idle still goes up and down. I have checked the vac line under the engine cover and it doesn't seem like it would cause an issue because that sucker is glued down (at least on the 2011 models).

 

The 4 banger is not the problem. I had an evo 8 for 7 years and didn't have this issue.

 

Yeah mine does the same, floats ~100RPM up/down when sitting with no accessories on. I wonder if the idle air controller (or just the throttle since it's drive-by-wire?) over compensates both ways, making it just constantly bump up and down and never sit at its target.

 

i heard the evo X tune from factory is ****ty. it runs really rich. my friend had the same problem and he took it to church automotive tuning. the car gain 40 extra whp, 3 more mpg and the idle is dead on now without any fluctuation from just a basic tune.

 

mine also did that until I got it tuned

 

Mine was crazy (with a tune that the previous owner had) and after i installed a cobb ap it all went away. Later i Uninstalled the ap, removed the fuel pump relay for a few minutes, replaced and switched on and the car is idling beatifully... Beats the hell out of me but i know that did something. (In my case it was a horrible 500 rpm swing that would go up and down regardless ac was on or not.)