I drove an '86 Accord that had a similar problem, if I remember correctly it was a vacuum leak. Very long time ago and I never found out the specifics, I didn't even know what a vacuum leak meant back then.

As soon as it got a bit of temp. into it, w/out me giving it any gas, it would rev up somewhat slowly and then quickly drop before repeating itself. It wasn't a constant problem though if I remember, and it didn't surge or anything when it was in drive (auto).

ninjedit: actually, I can't even remember if it would continue, or stop, once fully warmed up... I think it stopped when up to temp., which wouldn't indicate vacuum, but FITV I'd think My memory sucks for someone who's never done drugs It went in several times before it was fixed is all I'm sure of...

this post was a mistake h: