Or that the lift pump has a leaky diaphragm - it works good enough at
running rpm to keep the injection pump supplied, but can't get fuel
there at cranking rpm...

If this is the problem, the crankcase oil is probably diluted with
diesel, and the engine shouldn't be run anyway.

bob

wrote:
I'd change the filters, re-prime and retest.

Also it's possible that the injector pump or lift pump has a defective
check valve thats allowing the fuel to drain off and not allow it to be
pumped into the injector pump.