3000teeth

I've dissasembled my Warm-Up Regulator (WUR) aka Fuel Pressure Regulator, cleaned it and am reassembling it, based on instructions I found here:

http://www.landsharkoz.com/tt/ttwur.htm

One thing strikes me as odd. I'm able to blow air through the fuel intake and outake and the top vacuum connection, but not the bottom vacuum connection that feeds to the spring base.

Is this normal, or do you think there is some sort of blockage?

Thanks,
Travis

928BC

It sounds like the "o" ring is leaking that seals the two halves of the wur, the lower vaccum connection sounds like it's sealed, and it should be. With a non sealed upper chamber you will be running a bit less control pressure.

3000teeth

Thanks Robbie,

I actually disassembled the valve in the top --I guess my question should have been phrased: "Should I be able to blow air through the bottom vacuum connection?".

Thanks,
I think you cleared it up for me.

Nice car & year, btw --same here!

-T

928BC

Travis just to clarify the vacuum connections....both the upper and lower ports should hold vacuum, and should not leak. If you left the old square seal("o" ring) in when you bolted the wur back together it is most likely leaking. I replaced that seal with a standard "o" ring, I just got 5 different sizes and choose the best fit. After getting into the wur your car might not run perfect until you readjust your fuel/air mixture.
You should proudly show your car year in your signature!!
79s Rock

3000teeth

Hey Robbie, isn't the O-ring the little rubber seal between the fuel intake/outakes and the steel shims underneath the four screws inside.

The square seal, definitely looks like it can use some help --may be the crux of my prob.

928BC

well there is a "o" ring that seals the steel diaphram as you are mentioning, but that "o" ring seals the fuel from coming in to the upper part of the wur where the spring/plate and bi-metallic spring are. If this "o" ring is bad you will have fuel inside your wur body
If the square seal is bad you will have a vacuum leak and your control pressure will be a little off.
If you want to test the seal splitting the wur bodies then blow air through the top port and spray the wur body with soapy water.

jpitman2

Wow, somebody actually using my notes, Cool! Hope you have gauge to test result...
jp 83 Euro S AT 50k

3000teeth

Hey JP, Yeah! Thanks. One question for you --when I opened up fuel intake/outake it had two steel shims in it, not one. One had a small hole in it, which lined up with the fuel intake hole, but this shim was on the button side,not the intake side. I put it back as it was when i disassembled it, but it didn't seem to make sense. did you encounter this?

As for a gauge --nope, don't have one and won't be able to test for awhile while I'm waiting for some other parts to arrive --everything's so old under the hood that every time I take something apart, i break something else.

jpitman2

IIRC there was only one shim in mine. I dont recall a hole either....The centre of the shim is pressed up by the springs via a tiny metal hat shaped thing, keeping the shim sealed against the centre O ring. When incoming pressure exceeds spring pressure, the shim becomes unseated and fuel goes out the return line back to distributor. A second shim would slightly increase the opening pressure I guess, and having a hole on the button side (away from the O ring) would never see fuel, so no chance to leak....Dont forget to get or have on loan the gauge stuff when the time comes...you can test system and cold control by jumpering the pump relay as soon as the system is leak free.
jp 83 Euro S AT 50k

hupp

The number of shims may differ between a 5-spd and AT WUR, which have different cold control pressure curves.

GRTWHT

Hey Guys, looking at my WUR it's part number end with 034.
I looked this up and it looks like it's for an Audi 5000 1980 model car, does this make sense, do I have an incorrect WUR fitted to my engine.

Glenn B
'81 928
Melton Victoria Australia

jpitman2

Hey Glenn, Wot u doing here? Mine, and most WUR I have heard of, end in 086 for Euro models, or ROW(rest of world). Assuming you are talking of the Bosch part no here of course. If it starts and drives ok, all thats left is to check pressures.....and maybe adjust mixture.
jp 83 Euro S AT 50k.

3000teeth

FWIW, I've seen plenty of aftermarket Warm-up Regulators on eBay advertised as working on 928s. I've had mine apart and it doesn't seem too complicated an apparatus, so I think you have lots of options.

hupp

The good WUR is key to having a reliable, well tuned CIS shark. If it were me, I would bite the bullet and buy a new one and be done with it. But that's me.....

jpitman2

I'm with Scott on new ones. My local wrench says he has seen reco WURs, but they never seem to be as good as new ones....Best solution is keep driving, and keep changing the filter.

jp 83 Euro S AT 50k