Z steppers not working after firmare update

Well, they work fine when I'm jogging(both at 1mm and 0.1mm) but if I try to print the left one is really loud, and doesn't spin as much as it should, almost as if the pot trimmer on the pololu were turned way down. The right one experences symptoms as well but not near as bad as the left. My X axis tilts more and more with every grind the steppers make. I just replaced the left stepper thinking it was the problem, but it still continutes. Replacing the driver had no effect. This happend immidately after a complete redo of the ramps/arduino firmware, starting from scratch and rebuilding marlin.

Any ideas as to what is going on?

update:
Ive swapped out the ramps board and it still happens. swapping the slot the motors are plugged into on the ramps causes the issue to stick with the plug, not the stepper. I was able to make it happen while jogging, it took quite a while of moving up and down, up and down, to make it happen.

Edited 1 time(s). Last edit at 01/02/2016 03:42PM by bodaciousbrian.

Suspect your max feed rate is far to high.

default in marlin is
#define DEFAULT_MAX_FEEDRATE {300, 300, 5, 25} // (mm/sec)
this is max feed rate for X,Y,Z,E

but needs to be
#define DEFAULT_MAX_FEEDRATE {300, 300, 3, 25} // (mm/sec)
for people with m5 based z (soom have even reported they need 2 for Z

jogging feed rate is part of the gui, but when printing it uses max feedrate

Edited 1 time(s). Last edit at 01/02/2016 09:01PM by Dust.

#define DEFAULT_MAX_FEEDRATE {500, 500, 100, 25}

That is what I had in config..

i've updated it to:

#define DEFAULT_MAX_FEEDRATE {300, 300, 3, 25} // (mm/sec)

Sure sounds better now! It doesnt seem any slower either. Thank you!