1993 Chevrolet Lumina spungy brake pedal

No, it will not. A faulty booster will cause a high, hard pedal.

What else has been done to the brakes and how did this problem start?

I installed a new master cylinder and I put a new flex line on the left front wheel, also cleaned the sliders and lubricated same, replaced both rear calipers, had rotors turned. I first bench bled the master cylinder and then again after I installed it on the car by cracking the lines one by one.I then power bled the whole system one more time. By having disc brakes all the way around, would that cause a spongy pedal? I am not used to a spongy pedal. Any help you could give me on this matter would be greatly appreciated. Thank you!

Lets clear one thing up first. GM brakes ALWAYS feel spongy when you are sitting still and pumping them but if the vehicle is moving it will stop long before applying that much force.

thank you for the information. I have a friend with an s10 pickup and it has excellent breaks. I wish my car had the same break set up, but it evidently does not. I guess I'll just have to live with it.
Thank you very much for for the information. Also I'd like today that I think you guys are doing a great job.

that was supposed to be (to say) not today sorry about that

Thank you and come back ay time.