Don't know why this stuff seems to run in spells, but I changed 3 gallons of
diesel out of a 6.6 Isuzu crankcase yesterday...but that's a story for a different thread.
This is a little strange.
Does the
engine run well, with no starting, full
RPM or
power problems?
If it does, I would make sure that the new
lift pump isn't defective, and that it is correct for the application.
As far as I know, the injection pump on this
engine doesn't have any rubber
seals that seal the
diesel injection side from the crankcase. The
delivery valves would leak to the exterior, probably the only ultimate source for diesel to get into the crankcase from the injection pump would be the copper
gasket (item 6 below), where it would enter the crankcase via either the rack/pinion (14/26) interface, or between the pump body and the guide plunger (18). Re-use instead of replacing the #6 gasket could cause a leak, as could dirt or faulty pump assembly---but the engine probably wouldn't run very well if that is the case.
Seems a case of simplest first (check the
lift pump), then bring the injection pump back to the rebuilders. There doesn't seem to be any other real candidates for where that amount of fuel can come from in that amount of time, at least not to my eyes...