Chevrolet Repair: hesitation, air control valve, 1997 chevy 1500

Question
I have a 1997 Chevy 1500 series truck that is hesitating on acceleration when the truck is cold.  The problem seems to go away when the engine warms up.  I have recently replaced the spark plugs, wires, distribitor cap, and rotor.  I have also replace the fuel filter.  Please let me know what other things I should look at for this problem.

Answer
Usually when this happens it is caused by the engine just plain getting old. I have had many people come to me with this and there really isn't a solution for it. I have even had the problem on a couple of my trucks. A mechanic will tell you the same thing. Now if the hesitation is really bad like almost wanting to die, I would have the Idle Air Control valve checked along with the O2 sensors. Since these two kinda work together while the engine is warming up. Sorry I couldn't be of more assistance.