We had a clients boat launched, 40' Cruisers Yacht, with twin 8.1 GXI-Ds. ran the boat for a few minutes to allow warm up and check water flow. The Marina owner drove the boat off the trailer and out to the docks. STBD engine died, just dead...no stuttering, no sputtering nodda....just dead. Temp and pressure were normal, engine would not restart. I went out to it the following day to diagnose. I put my Rinda laptop on it to check for codes...nothing.

So here is what has been done.
Lift pump pressure 10 psi with key on - verified with port engine
HP Pump on rail 40 psi key on - verified with port engine (settles around 37-38 psi after a few minutes)
Check spark with inline spark tester - strong spark
Swapped
cam sensor
crank sensor
ecm
pdp (relay/fuse block)
iac
map
ECT & MAT within 4 deg of each other
new plugs installed

took fuel sample from filter at pump (clear and good)
took fuel sample from rail (clear & good)
Batt Voltage is good (1 big battery bank shared between both engines)
swapped complete fuel rail ***'y (rail, injectors and harness).
Compression is 160 - 180 psi

It tries to fire but wont catch and run. I have talked to, and had volvo techs check it out and they are stumped. I called Volvo penta canada and explained the situation and everything i have done, even they agree it should be running.

I am at a loss here, I have 23 hours into diag and swapping parts with no answer.

I should also note that with the Rinda system hooked up, base timing shows 5 deg, but when cranking (200ish rpm) it jump between 5 and 28 deg (wot).

I need help here, is there anything i have missed?

 

Anyone have any ideas here?