My no spark issue turned out to be a bad crank pos sensor. I had replaced it because the original connector was starting to crumble. Cutting corners bit me in the butt because the cheapo FAE sensor I got for $50 was DOA right out of the box.

I swapped the old one in and it fired right up.

 

well that was easy,

FWIW I have found that using any electrical parts that are not Bosch in a 928 is a formula for a disabled machine.

 

Add heater valve to the list of parts not to cheap out on. The new Meyle valve I installed as preventative maintenance started leaking almost immediately and was quickly pouring out at least a gallon in 5 min.

At first I thought it was just normal burping air out of the system, but after adding 3 gallons after the initial fill and the ever increasing frequency of the "check coolant level" warning I knew there had to be a leak.

I swapped the old German made valve back in and no more leak.

Now the alternator isn't charging. 1 step forward, 2 steps back...