high and irradic idling

[5spdFTW]

my car has been idling around 2000 rpms recently, but after a bit of driving the rpms at idle return to the normal 1000. one time a few days ago the idling was irradic, it would rev up about 500 rpms then die back down, and then repeatedly do this.

i am worried because i had an eclipse do the same thing before it threw a timing belt and trashed the head. i have looked at the timing belt on my talon and it has no visible wear on it, but it is offset to be flush with the side of the cam gears closest to the valve cover. i heard this was normal, but i dont want to lose another head due to a timing issue.

 

[the_mork]

Higher rpms at startup usually just mean its running rich to warm the engine up and are entirely normal, as far as the erratic idle you might try checking for vacuum leaks, use a can of starting fluid or ether and spray it around on your vacuum lines if your car idles higher or tries to die then your vacuum leak is in that area once you've found and repaired the vacuum leak or if you didn't find one buy a can of seafoam and run it through your car through a vacuum line search for "seafoam" to find a thread with more information on how to use the stuff and what it does than you'll ever really need to know (15+pages). Also if an N/T is anything like my GS-T if you've run the battery down or reset the ECU lately the computer could just be trying to calibrate itself and find good settings.

 

[5spdFTW]

it might be the weather chages i am thinking. it seems not to be sa bad when the temp outside is warm. liketoday was 60 or above and it didnt idle high at all when i started it up to leave school, but it did idle higher in the mornign when it was cool. i am only worried cause it just started doing this a few weeks ago.