Hey i just purchased an 2008 acura tl a little more than a month ago. The car runs perfect other than this one problem that just started. When im sitting still the rpms will go anywhere from 600rpms to 1100rpms. I talked to my brother briefly and he seems to think a dirty throttle body. A friend said mass air flow senor but i feel that would throw a check engine light, which there is no check engine light on. I was just wondering if anyone has an opinion on what it could be. I haven't checked the throttle body yet. Im thinking about putting in a cold air intake too.

 

Does this seem to happen only once the engine reaches normal op temp or does it happen only when cold?

A good cleaning of the TB is never a bad idea. A can or two of cleaner, a few rags and a bit of time.....be sure to get both sides of the butterfly....also an old tooth brush makes quick work of this job.

 

It tends to do it more when cold but it has done it when fully warmed up. I will definitely clean the TB and see if it stops.