Why does my truck have a problem cranking back up

So I have a 2003 Chevy Silverado 1500 I have
replaced the battery the mass air flow sensor I
have replace the fuel filter I have put a fuel
pressure gage on it while the key was in the
on position it was reading 52 the fuel pump is
kicking on I have cleaned the Throttlebody so
now my issue that I am having is when I start
it up in the morning doesn’t matter if it’s cold
or hot it fires right up I’ll drive it 15 min up the
road to work and then it sits from 7 to 3:30
when I get off work I go out to crank it up but
all it does is turn over but doesn’t start so I
turn the key back off and try again I
sometimes have to do this about 3 time or so
but if I press the gas pedal a little bit while I’m
cranking it sometimes it will fire up quicker I
need help I’m replacing a lot of part and
nothing happening and I have no check
engine light on everything ready normal on
dash even when it’s acting up and now a new
thing also when I took the fuel cap off to put
gas in it was under a whole lot of pressure like
a lot