I was having this problems when I first installed my lite 6 too. It was jamming because my ptfe wasn't in all the way and a little bit of plastic was leaking out at the end of the tube. What solved it for me was:
1: I pulled the ptfe tube out and heated my nozzle up to like 240 to melt all the filament out. Then I unfolded a paperclip and pushed and scraped around from the top to make sure no plastic was left in there at all.
2: When I re installed the ptfe tube I fed it in by hand as far as I could then I squished it against the filament gear and extruded about 2-3 mm. This jammed it in there a little bit more than I could by hand and made sure it was nice and tight. Then I used a razor blade to pull the black collet up while the pressure was on to make sure it didn't come loose again.
3: Finally I had to up my temperatures by a significant amount to get my filament to flow through freely. I was printing at 195C and now I'm currently printing around 230C.
Hope this helps you in some small way, I was getting frustrated too but the guys in this forum helped me out and now I'm quite pleased with the lite6.