[T2] Why won't it start

[steve blackham]

If you have checked fuel to injectors (pulled at least one, and checked spray), spark, and timing (rotate dizzy while cranking to see if timing is off), then I would check for a massive vacuum leak. Had the same problem on a Vanagon.  Was the elbow on the auxiliary air valve: http://www.germansupply.com/home/image.php?productid=16902

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Could be somewhere else but this is the first thing I'd Check.  If you have a blower nozzle on a air compressor I'd plug it in here to charge the vacuum system and intake manifold.  If you hear a hiss, there's you problem. 
If Nothing else works, drill an 1/16th inch hole in the air distributor and spray starting fluid into it with a carb cleaner tubes as you crank the engine.  If that doesn't work, you've probably miss timed the cam and valves in your rebuild.
S