car won't start after injector o-rings replaced
 

so i helped my brother replace the o-rings on his injectors today. we labeled everything that we took off and did everything step by step. the car started for a few seconds but sounded a little hollow so i turned it off. now it won;t start. dies it just need to get fuel back into the system with a few more cranks? we put all the vac lines back in there corrrect places and the sensors are back in there homes too. any ideas??????