I have noticed my car idles around 2,000 rpm when i am stuck in stop and go traffic for more then 10 min. I never really noticed this problem before but i commute for work now and i can only trace it to the car bring hot.

Any ideas?

 

Carb clean the TB & IM.

 

i just got the bored throttle body and intake manifold six months ago. and other ideas?

 

Wow I had the same exact problem. Try rerouting the throttle cable, my problem was when the engine got hot, the rubber on the cable softened and would stick.

 

thanks i never thought of that ill give it a shot, it would make sense with all of the heat from the turbo.

 

when it happens, try pulling the throttle pedal up, see if it drops down, i'm having this problem right now..

 

It's the throttle cable sticking, like I said, try moving it and see what happens.

 

I rerouted my cable and it seems to have fixed it

 

I know this is years later - but I am having this same problem. I just got the car 6 days ago and it idles at 1000 RPM exactly, doesn't matter how long the car has been running or driving or anything - whenever I am not moving the car idles high. I talked to the local Mitsubishi Dealership and the service writer said he vaguely remembers a service bulletin where the dealer would load a "system upgrade" or something onto the ECU to solve the problem. Anyone ever heard of this?
I haven't tried the throttle cable trick yet - that will be my next step and we'll see what happens, but I am curious about this so called "service bulletin" he mentioned.
Thank you!

 

Next time it happens, pull the throttle pedal up and see if the RPM drops back to normal. If it does, it means it's your cable.

 

In 2004EvoVIII case, it's more likely that someone played with the idle screw than his cable expanding with heat. He has the problem from cold to hot, which means he doesn't have the same issue the OP had.

2004EvoVIII, There are likely 2 possibilities in your case. Either the throttle cable was installed to far on the 2 holding screws on the intake manifold(which keeps your throttle plate partially open at all time), or you need to play with the idle adjusting screw.

 

I just went outside and turned the car on and started checking out the cable and such. The cable is not stuck or melted or sticky, like Rancid was thinking, AND there is plenty of play in the cable from between the spot where the two holding screws mount to the intake and where the cable connects to the TB - there has to be at least 1/2" of play - so I know the cable isn't too tight...

The only thing I can think of at this point is this adjusting screw - any chance I can get a location on it? I'm hoping this will be an easier fix then It's going to turn out to be, lol...once I get to work at my dealer I'm gonna pick up some TB cleaner and see if I can clean it up a bit as well.

Also - I called the local dealer and talked to a technician and a service advisor and both said they remembered something about a ECU software update for the Evo's to correct a "racing idle" but couldn't find anything in the service bulletins listed

 

Are you having this idle issue on a regular Lancer, or an Evo?
I'll try to get you a screenshot of where the adjusting screw is.


Edit.
According to the manual, it's where the screw driver is being inserted in the attached picture.

 

2004 Evo 8 - I have cleaned the TB, checked the cable, checked the pedal and all of that stuff checks out good. I'm beginning to think that there is a boost leak somewhere, which means it's time to build my "Home Depot Racing" (4RETECH) boost leak tester again like I had on my WRX. Hopefully it's something easy, cause I am not in the mood for this car to turn into my last car, haha..

 

In this case you may want to post your problem in the Evo section of the board. This part is more for the regular Lancer crowd. The Evo crowd may have better pointers than we do and you'll prolly end up fixing the problem quicker with their help rather than ours