"4K miles on veggie blends with kero and DinoD no mods. 10K miles on flatplat heat exchanger and various diesel/veg blends."

I think that I have just found the problem.
You probably have stuck rings.
Maybe another case of "Death in a Jug"
There is the alternate fuels sub forum, maybe some one there can help you.

__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving