Ossiblue, thank you for your comments. This helps me to clarify~
I did purchase all new lines, tunnel pressure line and and tunnel return line, new filter in tank, and all new lines that make up connections to the filter/accumulator/ and WUR, etc. Everything new.
"I believe, on your car, the return line from the WUR runs up to the rear of the FD where it connects with the fuel pressure relief valve. From there, both the FD excess fuel and WUR excess fuel share the same line back to the tank."
Yes, that's correct see illustration below:
"Your test description sounds like you disconnected this common return line without isolating the return line from the WUR."
Yes, in my first test I did this. I was trying to see if there might be a clog in the return line at the tank. But then reconnected everything and moved on to a second test which I called the "WUR Bypass test"
I had concluded that the constriction might be in my WUR. What I was trying to do is bypass the WUR to see if fuel would flow freely through all the lines. I connected "B" see illustration below to "B" above and "A" to FD with the fuel test gauge in between and valve open.
(copied this image from other post)
What I am discovering is when I am doing the standard Fuel pressure test my pressure is way, way too high. What I have tried to do is isolate where the constriction is and it would seem that fuel is not getting through the WUR... my pressure goes high and stays high 4.8bar.
When I bypassed the WUR, the fuel flows freely and there does not seem to be any constriction in any of the lines.
BTW, I did disconnect both fuel lines from the WUR and blow compressed air (60psi) on the WUR fuel intake side, very little air would pass through. But I don't know if this is proof that the WUR is clogged. Which begs the question, do WURs get clogged? As I mentioned the screen looked clean so it would have to be an internal clog.
All the Best,
Brian