2003 Silverado Starting problems

I have a 2003 Silverado x-cab with a 4.3. It has started sputtering badly after it sits for a few days even after I changed fuel filter, plugs, wires, and air filter. When I am driving if I give it to much gas it will sputter worse and if I don't let off of the gas it will die, and is very hard to get started again. I just replaced the starter last week and have not been able to start it. Now the new started sounds like it is dead too! When I turn the key the starter sounds like the gear is spinning but not catching anything. Any help would be greatly appreciated.

Well ,from trying to start it too much you may have ruined the starter! Take it out and have it checked. When you take it out look in the whole and make sure the teeth are not missing from the flex plate. If all is well and you put the new one back in and it turns the motor then you can troubleshoot the no start prob. And while you are at it take the battery out and have it checked also. Just about all parts stores can check them .

http://www.2carpros.com/topics/stalls.htm
http://www.2carpros.com/first_things/engine_stalls.htm

good starting points

as of starter starting (spinning) but nothing happening, you have 2 possible causes:
1. bad solenoid on starter, also known as bendix. it can be replaced seperate from starter. try tapping on starter body with hammer handle, and if starter comes back to life - hey, you know it's bendix.
2. chipped tooth on flywheel. and of course, starter's gear has to be just right against that chipped gear. usually, you can get to flywheel from the bottom, many cars have a seperate cover that covers bottom part of the flywheel, so it can be turned some with like a large screwdriver or prybar. just to make sure that it's not flywheel.