Brake Problems !!

Cant seem to be able to bleed my brakes after putting new longer lines on with new lift.
Pedal will not build up pressure, do I just keep on bleeding, should the engine be running, or do I now have a master cylinder problem ?!?!?!?!?
Any input out there, thanks for your help in advance!!!!

if you let all the fluid out of the mc it's going to take awhile. make sure you keep the mc full and keep bleeding.

engine off

Thanks for the quick response, I'll keep at it with the motor off!!