Last 6 months 2000 ford Windstar dies when @ a red light or when turning a corner. This morning it didn't start. Everything electrical in van still works.

Last 6 months the van has been dieing when slowing down at a red/stop light or when
turning a corner. The shift gears are off...meaning I have to put the gear in "N" turn the
key over then put it in "R" to turn the van on. Sometimes I need to put the van in "N" when
at a complete stop to keep the van from shaking. This morning I attempted to start the
van but nothing just a "clunk" noise when turning the key over (to start). Tried jumping it
with jumper cables. Battery is still good. Everything in van still works fine (light, windows,
etc).