Which motor are we talking about?
Mine in my 98 were Double Platinums and I believe I replaced them with the RS232 Single Platinum AC-D's.
I also put a set of Bosch's in at one point and I remember the idle was great for 3k then it was horrible and stumbled a lot.
Thinking about it, I might need to change mine again as i'm approaching 150k. hmmmm