Hello all - myfirst post. Tons of great info here!

My 1999 isacting like a manual transmission car all of a sudden. When pulling away, it stays stuck in lowgearwhile the revs continue to build. Twice while doing this, I've parked, turned the car off and restarted, then pulled away only to have the car stall (violently) as if I popped the clutch in 5th gear. Most recently, when restarted, the car idledwith a clicking sound like baseball cards in the spokes of a bike wheel.

Before I go to a tech, I want to have some idea if it's an electronic problem, or a mechanical problem.
(I think the clicking at idleanswers my question!) Any advice? Thanks in advance.