i have a 92 sc400.
my car started stalling at first then the idle started bouncing
i have changed fuel pump,fuel ecu,iacv, and that lil box on your intake.
still had a high idle after all that!
now on my way to work the car stalls and will not start!!!!!!!

 

sounds like a vacuum leak to me

 

And just one exclamation mark will do.

 

^^^Are you sure!!!!!!!!!!!!!!!!!!!!!!!

OP, did you do any maintenance, or take the car in prior to the issue? How long did you have problems before the car stopped running? How did the car run while you were driving it? By wont start do you mean it cranks fine but wont turn over? Need a bit more info before any of us can do more than throw guesses at the vast amount of things it could be