ok so heres the deal my moms 91 accord was running rough so i changed the plugs and cleaned out the TB and replaced the air filter about 3 weeks ago. The car runs fine and just last week it started doing this when put in park it will rev up to 2000 then drop to idle 900 or 1K the rev back up and drop again it will do this all day long. Other times (when cold) it will rev up to 2K which is normal for cold startup then just very slowly keep climbing. Whats the deal guys i have to get this thing right so my mom can get to work tommarow. BTW the car has a F22A6 engine and is auto.