So here is an update to this thread. It turns out that every time my injectors and/or injector pump has failed was because immediately before that failure I had experimented with making diesel fuel out of Waste Motor Oil (WMO).
A few weeks ago I began experimenting again with WMO to understand it better. Rumor has it that WMO and WVO are incompatible, so I pumped out my main 30-gallon (120L) fuel tank
, then processed 20 gallons (80L) of black diesel into that fuel tank
. The engine ran fine for three days, then there was a precipitous loss of power and increase of smoke from the exhaust, and a rash of plugged fuel filters.
That weekend I pulled my injectors and found them coked shut. I replaced those injectors with a set that I had coked up from previous similar experiments and had cleaned in lacquer thinner. I also pumped out the fuel tank
and flushed it out with gasoline, then pumped it out, then flushed it out with lacquer thinner, and back-flushed the fuel filters several times, and refiltered the fuel.
The engine ran much better, but has not returned to its former glory, so this weekend I plan to pull the injector pump to see if its internal screen is plugged and/or the pump is toast. I plan to have a replacement injector pump ready.
So, in conclusion, alcohol in the fuel blend had nothing to do with the IP and injector failures, and everything to do with the incompatibility of WMO and WVO. Blending these different oils together produces a precipitate of about 10% of the solution. The precipitate is primarily free carbon solids and liquid lacquers, together they make a rubbery like glue that glues up the injector pump and cokes up the injectors.
So does anyone know where I can purchase a repair kit for a STANADYNE DB2 Injection Pump?