My 90 does not, but it does idle around 1K.
I just ignore it, but thinking about a surge issue, im wondering if there is any pattenr, does it only do it when you start it while parled pointing up or down hill, or when your foot is on the brake? (Brake booster).
Does it have ANY discernible pattern?
If random, perhaps a wiring issue, a faulty O2 or MAP connection can cause some funny things....