How to test injectors.....

[Camaro9969]

So got the motor in on the lq4 anyone know how to test to see if the injectors are firing? using stock fuel set up just to get this motor running and switching everything out. little detail about it is theres spark and fuel pressure up to the fuel rails.......if you spray starting fluid in it will try to fire up but just wont stay running. Any ideas? Everything is hooked up got a new oil pressure sensor coolant sensor and everything but the evap canister purge valve is hooked up.