Engine shuts off while coming to a stop or slowing down.

My 1998 honda prelude engine shuts off while coming to a stop sign or stop light, specially in the morning when the engine still cold. I just had my timing belt changed by a local mechanic, been having problems since I got my car back from them, they changed the idol motor, costed me $300 more, the problem is still there. After engine dies, I restart the car right a way, it'll be fine till next stop light. I took back to that mechanic 3 more times after that, they can't figured it out. Please help, where should I start looking? Thanks