RE: [A/S] Diesel Fuel Truck stops and Running out of fuel

["Oliver Filippi" <ofilippi@xxxxxxxxxxxx>]

Running out of diesel fuel on older diesels which use the injector pump to
overcome the spring pressure in the injector nozzle must be bled (get all
the air out of the fuel line from the injector pump to the injector) for the
engine to run. (Fuel is incompressible, so it forces the injector to open.
If there is air in the line, the air compresses but the injector doesn't
open - so nothing happens.) I ran out of fuel with an 80's vintage Mercedes,
and had to help the Mercedes roadside assistance mechanic bleed the fuel
system to get the engine running.  It was a two man job!  Bottom line, don't
run out of fuel!

The new direct inject systems with a pressurized fuel line (thousands of
psi) and an electrically actuated injector valve probably don't have this
problem, and will self bleed unless there is a problem getting the high
pressure pump to work.  Here the bleeding will be between the low pressure
fuel pump and the high pressure fuel pump rather than the injector pum and
the injectors.

The quality of diesel fuel purchased at truck stops is likely to be better
than that purchased at a diesel pump at a local gas station.  The reason is
that the truck stops know how to handle it.  Water is a no no in diesel
fuel.  Often it contaminates the fuel if the storage tank runs low and
moisture can condense on the colder upper portion of the storage tank and
drip into the fuel below. Truck stops have higher turnover and more frequent
deliveries and keep their tanks full.  Also, they likely pay more attention
to the filters installed near the dispensing nozzle (and use better quality
filters).

Oliver Filippi