I have a
Perkins 4-108 in my 1971
Cal 39. The original
engine was a
Perkins 4-107. My
fuel turns black after it has returned from the high pressure
pump. It is obviously getting lubricating
oil in it. Years ago when I was doing deliveries I had a
boat where the
oil level on the dipstick rose and there was lube oil in the
fuel going to the injectors. A
mechanic in
Santa Cruz told me not to worry for the remainder of the
delivery to Southern
California because "a
diesel engine can burn lube oil just fine."It is NOT
diesel bugs or any other thing in the
tanks. I have had the
tanks scrubbed and the fuel polished. The
boat has two fuel tanks. I put clean fuel in one tank and put the return fuel in the other. The clean tank stays clean. The "return" tank has black fuel. I'm not sure, but I think that lube oil is getting into the fuel in the high pressure
pump, but having the pump rebuilt seemed to do nothing. The engine runs fine. It does not smoke (except upon startup for a few seconds). It's been this way for the last 8 years, including a couple
Baja Bashes (and attempts of
repair by mechanics in San Diego). Is there anbody on this forum that has had a similar problem? And how was it
solved?