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The accompanying pic on the original post is not visible on my browser for some reason. However, on the typical injection pump on the QM and GM series Yanmar engines the bleed screw on these injection pumps is on the inlet / low pressure side of the pump. Once the inlet side and piping/hosing between the lift pump and injector pump is "bled'' and clear of air and fuel is flowing to the injector pump ( all the fuel delivery system between the tank and the injector pump is free of air), such injector pumps and the remaining tubing all the way to the injectors rarely needs to be 'bled' as the high pressure from the injector pump will usually fill it and clear any air.

Rx: Rarely does one need to bleed air 'downstream' of the injector pump on most Yanmar engines. Just bleed the air 'to' the injection pump bleed screw and the pump pressure will then clear all the remaining air up to the injectors; although, you may have to wait a bit while the starter is turning the engine and the injector pump and downstream lines to the injectors are self-purging themselves with air and/or only a single cylinder is 'firing' and the engine is running 'very rough' until the other injectors and their supply tubing are fully purged of air.
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