Truck starts only if I pull start it?

I have a 2000 chevy truck 350 vortex 3/4 ton gasoline engine with 62000 miles. Its got new battery fuel pump, and alternater. My problem is the engine will not start unless I pull start it. Once it starts you can kill it and it will fire right back up. The next day you can try to start it and it turns over great and you can smell gas and it is firing at the plug wires but wont start unless you pull it about 10 feet then it fires right up. You can then kill it right away and it will continue to crank right back up. The next day you have to pull start it again starting the whole process over again. Any help would be greatly appreciated Thank you. Jim