Chevy Truck hard starting

1999chevy truck one ton dually 454 motor have to turn over alot to get it to start seams worse to start after it has been running. Seams to fire right off when it's cold, you also smell fuel after it starts, had to replace catalytic converters. Fuel pump was replaced then again about 10 months later (under warranty) Mechanic did'nt like pressure, still doing same thing. When cranking it seams like it starts sometimes when you release the key, coincidence maybe, they say no codes are showing up can't figure it out.