00 Jimmy runs rough after start up

I have a 2000 Jimmy that after startup idols smoothly but when you depress the accelerator it sputters and sounds like it misses. After 20-30 seconds it smooths itself out and everything is fine. It only occurs right after startup. I have replaced the fuel filter but still no success. The only thing I can guess is it is either a plug, wire or distributor, or it is an injector. Any solutions?

Welcome to the AF Board.........

When was the last COMPLETE TUNE UP on your truck?

AC Delco Platinum Plugs .060 Gap
AC Delco Dist Cap
AC Delco Rotor
new Ignition Wires (Taylor makes the best wire's I've ever used, IMO)
new Air Filter
new PCV Valve
Clean your Throttle Body
Clean your MAF Sensor

I also throw in a black Bottle of Techron fuel injector cleaner and give it a full synthetic oil change and filter to complete my truck's tune up. Although some people here don't agree with me on this, It's just what I do...