Hi Jeffers, thanks a lot I hadn't realised that section existed! and it was helpful, I added a question to a thread on the subject Its been useful thank you. Do you know how to get to the mechanism please with your experience, i want to check it as I had injectors that were blowing soot everywhere for a while before they were tightened up, and i want to have a look to check the vent/ flap is not simple sooted up, though I appreciate the problem sounds like it may be the teeth Thank you and kind regards. Sianna