Ducati,
Though I have read through thread-after-thread where "nailing" has been used as a term to describe what sounds to me like nails being run through a pop corn popper, I didn't actually find a definition. I gave up reading the posts to find an actual cause. I am certain it must be in these forum archives somewhere . . .

My '87 300TD has what I consider they refer to as "nailing" when it idles and to a lesser extent on initial acceleration. When I run diesel additives it is less than when I don't. Diesel purge, such as LubroMoly, is a concentrated injector cleaner. I recently used it for the first time (ordered it online) and found it reduced what I consider to be "nailing" substantially. The idle became smoother while performing the purge process and continued. Less smoke on start-up. I have never noticed a lot of smoke since taking ownership of the car and it does still smoke a very limited amount. Having 137k +/- miles with possibly the original injectors I suspect I will see other gains when these are replaced.

Do a search for "nailing" and you will find many threads to read through.

__________________
Steve
'87 300TD - 132K - Soon 4-Sale
'84 300D Turbo - 122K - Driving
'77 VW Type II - 77K - Restored
'08 250EX Ninja
English Bulldog (Brier) - My best friend. Passed away 12/02/04 while in my arms.