Is the rack behind the cover that's above the oil filler? Or is it over by the side of the engine? I think we'll need a few close-up pics to figure it out; I've looked at as many HA2 pics as I can quickly find, and none of them offer any clues as to exactly where it is.... I think I've spotted the lever you're referring to, but it looks like that rotates a shaft under one of the cylinders, so I'm not really any the wiser.
If you can/already have exposed the rack, then (because the engine is not running), the governor should be pushing it - quite hard - to the fully open position, so if you're not able to push fuel to that point, then it suggests the feed line to the rack is blocked. If you can get fuel at the bottom of the injector pipes, but not the top; then (at a total guess) the HP pump is faulty. Or maybe your injector lines are blocked, but it seems unlikely they'd both be blocked, unless someone's run coal through it in a previous life.