For a diesel engine to start I was always led to believe that you need air/heat, fuel, proper compression, and of proper timing of it all.

Where I am going with this is: You have isolated the fuel supply, and it sounds like you are getting fuel, possibly low pressure, but some fuel. The air intake should be fine, but it would not hurt to check it.

Glow plugs. Pull the wire off the plug and put your red/positive voltmeter probe on the wire, and the black probe on a good ground. Have a helper cycle the ignition switch and see if you get voltage at each glow plug, and for how long.

Lastly, have you checked the static/basic timing of the motor. Chances are slim, but it could be out of time. A good valve adjustment might not be out of order either. If the valves are out of whack, you will not get proper compression to start/run.

Just my .02 you are headed in the right direction, let us know how it goes!

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2012 Mercedes ML350 Bluetec 91K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 231K (mine)
1998 Volvo S70 T5 Turbo 196K (kids)
1994 Ford F150 4WD 249K (firewood hauler)
1983 Mercedes 300D 376K (diesel commuter)