I have a 93 Honda Del sol. When the car is cold it starts and runs just fine. After it warms up and is turned off (i.e. driving to shopping mall) it will not start. It tries to start and comes close, but just won't turn over. If I wait a few hours for it to cool down, it starts again with no problem.

The problem seems to have started after having a new muffler installed,but it could just be a coincidence.

Replacing the Ignition Control Module (ICM) and coil, located inside the distributor, usually solves this problem. Be sure to apply silicone heat transfer grease to the back of the new ICM. If the problem persists, replace the main relay, especially if the problem coincides with the temperature increasing inside the car during the day.