HDJ multivalve, turbo and vacumn line queries

What a great site.... just getting into it.
96 GXL multivalve 270K so far, and looking to get to 500K.....
I love my multivalve but.... wondering if any one can help
Hassle 1. Seem to have lost vacumn on both a/c idle up and p/s idle up. Brake boost ok. Vacumn line hoses ok First time I pulled off the small take off line at vacumn pum - no vacumn and the (very) small branch was blocked with black dust (assume pump vane dust). A/c idle up worked a couple of times, then stopped again. Cleaning, blowing, sucking ... no change. P/s idle up still not working. Can get unit to work when sucking (caution, tastes like *%^#^%#) Any ideas ? even thinking vacumn lines, where they cross manifold may have been swapped. (Got injectors changed @ 250K)
PS Any one know what the vacumn line does that goes from air heat element area, across to a switch mounted on side of a/cleaner? Dont seem to get any vacumn out of that either.

Hassle 2 - Very poor off boost performance. Been trying mods as per lcool site. Not a lot of change. Would the above problems affect turbo characteristics ? Several vacumn lines going to pump.

Gregories manual not showing any decent pics or info on any of the vacumn or injector pump setup.

I know I will have to eventually get my "child" to Adelaide for professional attention, ( but I suffer from the tyranny of distance = 500kms) and I hate the walk home.

Thanks in advamce.