Long start problem (SOMETIMES)

So i just bought my 2004 Mustang GT (40th Anniversary) convertible with only 60,000 miles on the clock...Clean title and the whole works but ive got a lil issue..Sometimes and this only happens like once every two days (and i drive every single day at least about 40 miles per day) when i come to start the car up, it sometimes takes like 15 cranks to start up as if its HARDLY starting. other times the car starts right up after like 3 cranks. I have changed the spark plugs (NGK inidum), flushed the coolant, Synthetic oil change, and i only use 91 octane fuel. When car is running, it runs smooth like no tomorrow, no issues, just the starting portion is weird. Could it be my fuel pump or starter motor?

CAR MODS: K&N intake, BBK throttle body, full Bassani exhaust

thank you everyone for taking the time to read up and help out