Is your tank a HPA tank or CO2 tank? You can't run CO2 on ETeks.
Assuming the HPR and LPR haven't been messed with and are working properly, then you can go ahead and try firing it. I'd check the set screws on the LPR and HPR to make sure they are set reasonably. The LPR set screw I believe should be flush with the front cap, the HPR I'm not sure. Just to be safe, you might want to set the HPR very low (turn it very far out/in, whatever the manual says to decrease pressure), gas it up, and slowly increase it until it shoots normally.
PS: This belongs in the Eclipse section (
http://www.paintballforum.com/eclipse/), not in general chat.