Idle... "wierd"?
If by wierd you mean:
hunts up and down, rising by as much as 1000rpm then falling again, nearly stalling sometimes..
Search up on the following:
CHECK YOUR IAC.
CHECK YOUR EGR
If by wierd you mean:
stays at a very high RPM and perhaps even CLIMBS when you depress the clutch (possibly even makes a fog like noise, but not always...)
Search on the following:
CHECK IN TO THROTTLE HANG(TH) and/or MOOSING
If you don't mean either of those... what do you mean?
Ray