Intermittent engine stall

I own a '93 SE with 90,000 miles. While travleling to work I went to brake for traffic and after lifting my foot off the accelerator the tachometer dropped from 3,000 to zero RPM and the engine stopped. I pulled over to the shoulder. The car was hard to start but finally did. I entered traffic again and the problem occured after slowing for a traffic light. On the way home the symptoms occured two more times but the car never died. I learned to power-brake when slowing down. I got the car home. I decided to take the car to our local mechanic. The honda would not start. I cleaned the ignition ignitor in the distributor( and had it tested at NAPA{good}). I tested the fuel pump (good). The car started just fine and I drove it to my mechanic. They drove it all day and could not replicate the symptoms I experienced. Any ideas on would else could cause an engine stall when slowing down?? Thanks

Scott

How much fuel was in the tank?