My Suburban will crank but won't start

have a 1999 Chevrolet Suburban K1500 4X4
5.7,152,000 miles, just got it 2 months ago,dude I
bought it from said he put a new gas
tank,staps,and fuel pump in it,and new battery ,now
I had to do a few things to it since day one,new
exhaust from manifold back to exhaust tip,radiator,
oil change and full tune up. Which is air filter, rotor
button distributor cap spark plugs spark plug
wires,and ran like new,a month later it started
having issues starting, so I go through the trouble
of replacing, and mind you,after each part
replacement it still has the same result wants to
turn over but doesn't start,I replaced the crank
sensor,fuel filter,fuel filter relay,ICM,checked to see
if the coil had spark,it did,so didn't replace the coil.
So for shits and giggles I checked to see if the fuel
filter was acually new,so dropped the tank and low
and behold there was a few problems, it wasn't
new,imagine that,the previous owner dubbed a
little, the tank was new but didn't replace the fuel
pump,and came across a couple of other issues
while looking at the situation, one of the fuel valves
was broken and also the sensor on top of the
pump,the wires which is the 4 wire configuration
weren't all hooked up, only 3,he didn't hook up the
purple wire which is to the sending unit, and the
factory wires looked a little burnt ,replaced the
broken pieces,and stripped back the burnt wires as
far as I could without it being to hard to resecure
the tank. The fuel pump has that beautiful sound of
it working,but still no start,so I'm really scratching
my head about this awesome vehicle, I love the
truck but would be nice to get in it a start without
me having to shoot starter fluid in it before I start
my day,now mind you,after a ether start in the
morning some days it will start no problem
throughout that good day on the other hand some
days I have to shoot either and it what I need to go
back and forth throughout the day. Can someone
give me an intelligent answer or response to what I
should try next before I spend thousands of dollars
taking it to a dealer when I love to figure and fix
things out myself at this point I'm asking for a little
help