2 Extrusion issues

Printer
Migbot I3
MK8 extruder

So I've been recently having issues printing on my i3.
Layers were weak and it seemed like the filament wasn't being extruded so I bought a new nozzle for my printer and that didn't fix the issue.
I did a little harder look at the extruder motor its self an noticed that it didn't seem to be turning as quickly as it should be. Is the motor dead or is there some setting in Simplify3D that I may have screwed up.

Things I have Tried

• New nozzle
• Reducing tension on filament be fed into extruder
• Increasing flow rate and E-steps

The second issue which is also weird which I have never had happen before is that the Z axis doesn't seem to be raising as high as it should. Resulting in squished prints, for example an object that should be 10mm tall ends up being about 2mm tall.

Any help would be much appreciated
-CK
The only thing that seamed to make a difference was playing with the E-steps in the firmware/Settings of the printer itself.

Are you sure your z_steps are correct? What about the esteps? If you have an i3 with M8 rod, your steps_mm should be about 4000 to 8000 for the z, depending on the microstepping you use. For e, depends on your extruder, but if that made a difference before maybe you need to up it further.
A second possibility is underpowered z axis and extruder motor, due to stepper driver current being set to low. You could try increasing that slightly to see if it makes a difference (make sure you either power off the printer first or use a special antistatic screwdriver).
Finally, if you do have a spare motor you could try swapping the extruder one with a new one and seeing if it works better. Although as far as I know steppers don't fail too often, so it's likely one of the above issues.