Low power when warm for 1 minute after starting

This is a 1998 5.7L K2500 crew cab short bed.

After I have turned off the truck and it sits for up to an hour, I come back out, start up, sit there for about 15 seconds, and drive off.

I have 30-40% power when trying to pull out onto the major road or into traffic. This happens most of the time. As I push the gas, it feels that the engine is not getting enough gas. After about 20 seconds of seriously slow acceleration, it kicks in and I get full power.

The truck has 102,000 miles. The fuel pump is about 3000 miles old. The fuel filter is same age. This happened before AND after the fuel pump replacement. Original spark plugs and wires (plugs look quite good). The ONLY engine maintenance has been PCV and oil changes.

I did a search but did not find anything. Any thoughts? What are the symptoms of vapor lock?

You need plugs and wires, I would almost guarentee it. they may look okay, but the plugs can go bad.

I agree I probably need to change the plugs and wires, but how might that be the cause of this problem?