More likely it is the WUR (based on the symptoms you describe)... but the only way to know for sure is to use the proper fuel pressure tester to measure the control pressure. However, you do need the correct gauge, not just any pressure gauge - and they're fairly expensive. You need one specifically for testing CIS.
I recommend you pop over to the 924 board (
www.924board.org) and see if there's anyone close by that might have one - I know we have a few guys in CO.
If not, you should be able to find (either through a search or just ask) the current best/cheapest source for a CIS pressure gauge. I think JC Whitless might have one now...
Yeah, actually they do, but it doesn't show the valve needed:
http://www.jcwhitney.com/autoparts/Product/Pr-p_Product.CATENTRY_ID:2008126/c-10101/Nty-1/p-2008126/Ntx-mode+matchallpartial/N-10101/tf-Browse/s-10101/Ntk-AllTextSearchGroup?Ntt=CIS+pressure+tester
You'd need I think the $60 one.
There should be a valve in there you can close to measure system pressure; looks like, as its delivered, it will only show control pressure (which is more likely to be the problem, if it's the WUR).
The test procedure is in the Haynes manual - you do have that, right?