I have a 1998 Honda Civic EX that tends to shut off when I lift off the accelerator after taking short trips. After a few minutes the car will start back up fine and I'm on my way. The other night, I filling up the tank, and when I get back into the car it would not start. After a few minutes, the car will start and again I'm on my way. I'm thinking the distributor could be bad, maybe having a hair-line crack which tends to open up when the engine heats up. Would a bad TPS cause this? Maybe its just my imagination but the shift point for the engine's transmission seem to change before the engine shuts off. Again, maybe its just my imagination.

Anything else I can take a look at? My mechanic seems to think the distributor is bad; however, he isn't able to get the car to shutoff for himself.

Any help you can provide would be appreciated.

Replace the Ignition Control Module (ICM) and coil inside your distributor and your problem should be solved:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-4.html#post265896

Common problem on Hondas.