Make sure the long bolts with springs are tight enough. Easy enough to check, just extrude from Pronterface and squeeze to move the guilder closer/tighter to the main extruder block. If it feeds tighten up the bolts. Also make sure the guilder bearing moves freely without and filament loaded in but with the springs and bolts on so it's in position. I'm assuming the extruder motor moves the gear when commanded from Pronterface. Also, I find 210 is too low for my i3v. My ABS range is 225 to 240. I've never tested at what temp ABS starts to extrude from my printer, but the 225 to 240c spec works best for my prints.