92 Integra ls

The starter cranks but the engine only starts when cold or intermittantly when hot.
When the engine does start it runs just fine until it is shut off.

I have replaced the Distributor Cap, Rotor, Ignitor, Ignition Coil, & Main Relay.
Neither of these have cured the Problem....
I removed a Spark Plug and cranked the engine over and there is still no spark.
Any more suggestions based on experience would be appreciated!

I am contemplating replacing the Distributor housing assembly, and possibly the ignition switch if it controls power to the ignition system

Help.....