Not Even On Ether

A few days ago I asked for ideas about a 310 Waukesha turbocharged diesel that wouldn't start. I got a good diesel mechanic out and we checked out a few things. I changed the fuel filter and it may have had some foreign material in it, but the new filter looks good.
We changed out the little ball in the return fuel line. There is good fuel flow at this point.
The engine turns over quite well. There is not a whiff of white smoke. Sometimes if the engine has sat for a few minutes, it acts like there is a hint of trying to start on the first cylinder that comes up on the power stroke. Just one very quick and feeble "puff" that is immediately gone.
There is good compression on at least on cylinder, as we pulled the injector and checked.
There is good fuel at least to the pump and we think to the injectors. We get fuel to the injectors, we have not verified the amount
We pulled the air cleaners with no change.
Even when we sprayed ether directly into the air cleaner chamber (filters out) there is no rattle, banging or any other indication there is any attempt for the engine to start on ether.
Some have said this may be a pump problem. Please help me understand how a pump problem would explain why the engine has compression but won't attempt to run on ether?

Did you try towing it?

you are not getting fuel in the cylinder. Low pump pressure?

I'd pull the valve cover off and see if all the valves move, isn't gona start on ether if the valves don't open to let it in

I don't understand. I would think it would run on ether alone. Why does one need a pump for it to run on ether?

I agree that if the cam went out it wouldn't work. We've been thinking about that. But we pulled one injector and rotated the engine and it acted like it was operating right.

you need fuel to make ether work

Since you took one injector out, hook it up on the outside and see if the pump will open it. Has a check been made to see if the pump is turning?

The pump is turning per watching the mark in the little window on the side of the pump.

which injector did you pull? If you pulled #1 your still blind on the other 5 holes cause maybe the cam snapped right after the #1 lobes.

squirt a small amount of kerosene in the intake and see what happens if the rings have collapsed then the kerosene will expand them. Had this happen a couple of times on older tractors.