[PeteKz]

I opened up the 089 WUR, and while I was at it, I also opened the 033, side by side to observe the differences, which are significant. As several others have hinted, the vacuum works oppositely on these two WURs. That is, the vacuum pulls up on the regulator valve on the 089 when it is applied to the SIDE vacuum fitting, and it pulls up on the 033 when attached to the TOP fitting. I disassembled the upper chambers including the regulator valve itself, with the thin stainless steel disc inside, cleaned it all with carb cleaner, then gave everything inside a spray of WD40 to preserve surfaces, and put it back together. I did not completely disassemble the lower chamber of the 089, because the diaphragm in the bottom did not want to easily release, so I peeled up the side of the diaphragm and peeked in side, didn't see anything amiss, and put it back together. Separating the plates of the bottom chamber in the 033 was more challenging, so I let it alone. It wasn't leaking before I took it apart, and I didn't want to break something that wasn't broken.

The SP of the 089 remains unchanged at 71. the CP started out at 30, then rose to 54 (not running, connector plugged in, without pulling vacuum). Better starting pressure, the the final pressure is still too high. Arggghh. More futzing with it. I will also substitute the 033 and see what numbers I get from it. I might try to run that one instead.

Back to the original question: If you were building the best CIS system you could, which WUR would you use and why? (No point in me futzing with the 089, if another version is better for my purposes)