I have a 2001 Eclipse spider and when I am sitting idle the rpm's on my car jump up and down as if the gas pedal is being pressed causing the engine to rev. If I am not mistaken it looks as if my headlights dim when this happens. When it isn't doing this it idles so low that it is on the edge of cutting out the engine. Could this be from a faulty battery connection or something worse?

alisalane@hotmail.com

 

Most likely you either have an air leak like around the intake manifold or TB or you have a bad sensor. My guess is on the sensor. Do you have a check engine light?

 

Does it do it when the AC is off?

 

mine does that a little bit, it goes from 900-1500 or so, but that's only when the fan is on, other than that it stays at 900 when the fan is off.