If your coolant is too low.
If your idle is set too high.
If you have a vacuum leak (which in this case is a control leak inside the
thermowax Fast Idle valve bolted to the intake.)

"Max" <shmaxx@yahoo.com> wrote in message
news:8b62cebc.0309141356.63abcc10@posting.google.c om...
> i just bought a 1992 Accord Dx with 130,000 miles. When it warms up
> and is in park the idle changes from 1,500 to 2,000 rpm. It revs as
> it changes though, its not gradual. The car rides fine except for
> this. Does anyone know what ithis problem is?