I would check to see if you have a clog. I use a method called the cold pull technique, if you Google it you will find an answer. But essentially you set your extruder temp low, like 180*c and then pull out the filament slowly. Do that a few times and it should have cleaned the nozzle.

If that doesn't work, make sure the Teflon tube is clear from the hobbed gear. Also check the filament diameter using calipers to ensure its not oblong in one direction.