2002 Mistubishi lancer oz wont start (someties)

I have a 2002 Mistubishi Lancer OZ and it won't
crank sometimes. Everything in the car turns on all
the lights and all and sometimes when I turn the
key it's makes a little buzzing sounds you know
like it's Injecting the gas but the car won't start so I
have to kinda push it in a little hard and try that a
couple times and sometimes it helps. I recently
changed the spark plugs, ignition coils, and wierd
so I know that's not the problem anymore. Help
please and thanks in advance.