1997 Honda Prelude Alarm comes on

I'm thinking this is a 2.2- 4cylinder not 8.

Have you tried a different key? The system may not be reading that key anymore.

Factory security system?
If so,

The accessory security system has a cool feature that lets you know if there was a security system violation, what sensor was tripped the last time the system rearmed itself, and which sensor(s) triggered the current violation.
If the security system sensed a security violation and then rearmed itself, the tripped sensor warning gives these indications:

- The status LED blinks twice per second.

- If the beep (chirp) is on, the system beeps three times when you unlock the door with the remote transmitter.

- The parking lights flash three times when you unlock the door with the remote transmitter.

When you disarm a security system that's just been violated, the status LED can show you which sensor was tripped.
If you're diagnosing the system, this can help you pinpoint what you need to check. To make the status LED blink the code of the tripped sensor(s), press the disarm switch three times within 5 seconds of disarming the system. Then count the number of times the LED blinks, and post them.