98 work truck

i have a 98 chevy. w/t. its got a 4.3 with a 5spd. the thing is that recently it seems like if you take off easy from 1,000 to 2,500 rpms it has almost no power but as soon as you hit 2,500 it takes off. plugs were changed a month ago. this just started a week ago. wires, cap and rotor were all changed.

If its in neutral, will it revv up normally or does it rev slower until you hit 2500? also does it do it hot and cold? and does it do it through all the gears or just 1st, and finally when it takes off could it be that thats when the clutch pedal is completely released? or is it def. and RPM thing. Thanks

Check fuel pressure.

well i'm gonna check fuel pressure. don't know about the neutral thing but i do know it does it in all the gears. clutch has been replaced like 2 years ago. slave cylinder exploded. so all thats been done. what should the fuel pressure be. i know its got to be high cause of the type for fuel injection. as far as the clutch pedal, it does it completely released.

60-66 lb.