please help 93 1500 IDLE problems??

ok my baby is acting up. 1993 chevy 1500 4x4 z71 5.7 v8
i did plugs wires full tune up new belt new pulleys. used seafoam still does it.
ok ill be driving no problem and when i barely hit the gas to go and let go
it dies almost ALMOST but never has. itl kick below 1 000 rpm. and then back up to about 2000 rpm. it does this not every time. also if i go to punch the gas it will shift a little hard? timing perhaps i was thinking? help please any ideas are welcome?

Is it carburetated, throttle body, multi port or sequential port injection ?
Did you change the fuel filter when you did the tune-up ?
What kind of fuel pressure do you have ?
Sorry about all the questions but knowing what you have will help.

clean the throttle body, iac , make sure the tps is connected and aligned . you can ohm the tps and the ohms should change as you move the tps stem.if it tb and carb tb injectors are dirty.