Truck was in storage, they replaced the fuel pump. After 1-2 after driving it, it began to stall after decellerating from highway speeds to stop. Now will do it from time to time with decellerations of normal speeds. Took it to my mechanic who gave it a complete tue-up. However it continues to do it. Starts in the am on first crank, and after stalling will turn right back on. If i fill the tank with gas it will start right away. Does anyone have an idea what it could be.

it started about a week ago stalling periodically when I come to a stop the engine will stumble then stall, but will fire up after wards, will changing the pug wires cure this I'm at a loss here!!!!!!!!!!