"Roger Long" wrote in
:

I'm sure he meant "un(completely)burned" fuel. It's the ash of partly
burned fuel when the engine is too cold to promote full combustion
that causes the problems. It doesn't even have to clog the injector
enough to stop the flow of fuel. A little clot of carbon on a nozzle
can break the spray pattern and turn it partially into a stream which
has less surface area for its volume and thus burns less completely
leading to further carbon build up.



Sorry. I've been running diesels for lots of years and NEVER had an
injector clog because of the fuel. Injectors clog because of crap IN the
fuel, things high pressure injection pumps can't force past the orifice.
I've never seen any carbon on the outside of an injector clog it against
the hundreds of PSI of injection pump. I'm sorry. A little clot of
carbon could, I suppose break the spray pattern. I'll buy that. But,
it's never happened to any vehicle or boat or genset diesel I've had
contact with....and that's a lot of diesels.

Two things would cause the carbon....too much injection on too little
air...or...too much LOAD, which is normally what's up with that black
cloud of smoke at full throttle. In a boat, too much prop. There's no
reason for a diesel to make lamp black, especially not now with
controlled injection.

What diesel do you know of with this carbon problem, anyway? Carbon in
the pipes is normal, black, gooey snot saturated with unburned fuel a
diesel always produces. Diesels make soot because they run out of air,
usually about the time the exhaust port comes uncovered in a big 2-stroke
beast, or the exhaust valve opens opens, if it has one. But, that
doesn't "clog the injectors".

http://people.bath.ac.uk/ccsshb/12cyl/
I just wanna see and feel it run....(c;