I've got a tired 2.8 in a 91 trooper that i've put new injectors, new plugs/wires/cap/rotor, and performance 2.5" collector-back exhaust onto... as i've done this its hesitation from standstill has seemed to get worse.

Automatic transmission, btw.

if I'm already moving, throttle response is fine - but if i come to a complete stop, then step on the gas it kinda sputters and puts out nearly no power for 1 to 2 full seconds, then BAM comes alive and accelerates like it should. Next time I come to a complete stop, the same thing occurs.

Any ideas? timing? IAC motor?