crank sensor??

I had a rough starting 93 cavalier 4 cyl that would also die after driving awhile and not fire back up till it cooled down, diagnosed at a gm shop. They told me it needed an elec. ignition and a crank sensor. I got to the elec. ignition(real fun) but don't know where the crank sensor is. Any help would be greatly appreciated!!

i found the crank sensor, replaced it but its not running right, might have to replace the ignition next??

I replaced the Whole ignition and coil pack with a used set but no improvement. After 20 minutes of running it starts to run rough and lots of exhaust. Any Help?

Have you taken a look at the spark plugs?