I see air in both clear hard lines.

Old style primer pumps are prone to leaks, does fuel come out of the handle when you are priming the lift pump?
It may be time for a new design primer pump.

Also the rubber fuel inlet hose may have an air leak, especially if you can twist the line by hand when the hose clamp is at its tightest.

Fix those potential air leaks first, re-prime your IP (about 50-100 strokes), and then
crack open all five injector hard line nuts at the injectors.

Crank the engine (with the glow plug relay unplugged to save your battery), and re-tighten each hard line as they begin to dribble fuel.
They fill sequentially from rear to front (ie: 5, 4, 3, 2 and then 1).

Then plug in the glow plug relay and it should start up right away.

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78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022