is #1 getting spark? if it is then the inj is prob bad since you have compression. you've done the initial things:
spark
fuel
compression

once you get that sorted out if it still does it then see if it does it wot any earlier than just trying to cruise. if it does it as soon as you stab the throttle, then you may have the tps and map mixed up...won't nec throw a cel, but will cause the car to have issues.

what about ecu/tune? is it a stock ls ecu for the engine?

set the dist timing to 16* with a digital advance timing light w/ the svc connector jumped.