Captain Obvious

Agreed, but that's exactly what happens! The hard to believe-edness why it took me so long to catch on too. If you really study it though, there really isn't that much rotation. Especially if you start unstressed at the middle of travel. If you were to measure it plus-n-minus from there in degrees, it's really not that bad. You doing inner rears too? Note the teeth on the inner sleeve of the inner rear bushings. Those teeth are intended to bite into the control arm and washer surfaces as extra insurance to prevent the inner sleeves from slipping. Fridge is fixed. Garage door opener is fixed. Battery is still dead.

Is there a reason that you wanted to be way way advanced at idle?

If you're looking for new... Have you tried an Audi dealer?

Mike, I'm running the check valve with the Audi line on my car as well. I was just trying to provide other Z guys with as many different options as well. I've got baggies of extra O-rings... I gotta get my car back together so I can test that fuel pump!

My temp sender was intermittent. Would occasionally alternate between normal and open circuit. Some days, it would be fine, and other days it would be flaky. Replaced the sender and problem went away.

And I know it seems like it takes a lot of force to twist the rubber bushings, but to the springs and the weight of the car? Easy. Those bushings will twist alright! They'll twist, or they'll tear! And one more thing... The most common issue I can remember seeing with this type of bushing is that the mounting bolt or nut was not installed tight enough and the inner sleeve was allowed to rotate on the bolt. Galling, clicking, and mysterious hard to find odd knocking sounds usually result. PS - I'm not at all a suspension guy. I had an epiphany about this stuff a little while ago and it suddenly all made sense.

What you are describing is exactly how the rubber bushings are supposed to work. The only movement in the bushings comes from torqueing the rubber portion vulcanized between the inner and outer sleeves. Essentially, the inner sleeve rotates and the outer sleeve does not. That twists the rubber between the two. So, the spindle pin DOES act like a hinge, but the relative motion is not right at the surface of the pin. It's at the rubber. That's why (with the stock style bushings) it's so important to put it on the ground before you tighten up for the final time. You want the rubber to be "at rest" in it's unstressed natural position when the car is sitting neutral. That way, the rubber can twist one way when the suspension is extended and twist the opposite when the suspension is compressed. All the rubber bushings are like this too. Inner front, inner rear, outer rear. They all operate the same way. Interesting to note that the poly bushings do NOT operate this way. They rotate the inner sleeve inside the poly bushing and because of that, you can tighten them with the suspension hanging. And no... Mine isn't back together yet. Projects spiraling out control! Fridge died. Garage door opener died. Battery in one of the other cars died.

txvepr, For performance reasons, the best functional place for the check valve is back by the pump where it is on the stock system. But I agree that it would sure be convenient to have it up front. With that in mind, I've identified and purchased a fuel filter that fits the stock mount and accepts an alternate check valve to be screwed directly into the filter. However, I haven't yet worked out how to easily connect to the other end of that check valve and that's why I haven't talked about that option.

Hmmm... To be completely honest (and a little embarrassed)... I did not actually purchase one of those sealing caps for the banjo style. The cap shown in my pic is actually a Honda cap with the wrong thread pitch. I figured out the part number and verified that they were seemingly available on both RockAuto and ebay and called it a day. I figured that I had already spent extra money on several different check valve styles and for something as simple as that cap, I didn't need to buy one just to prove that I could. So if you go to Rock Auto's site and hit the part number search tab at the top, that cap comes up for $2.40. Did you try them? It appears they have them? If not RockAuto, they're on ebay. More money, but I'm sure they're available.

Bruce, Are you talking about the filter back by the fuel tank, or the one in the banjo bolt at the carbs? Have you got a pic of what you're looking for?

Thanks for the info guys. I think I've got a spare oil pressure sender in the garage somewhere and I know I've got NPT taps down to 1/8. If I get a chance I'll take a look and see about how many turns you would get before things start binding.

You hear stories and reports of water in the gas, but it's always anecdotal. Here it is for real and with pics! I wonder if you'd get a straight answer from the fuel station guys. Seems they'd be opening themselves to some sort of liability claim if they told you about other complaints. I know condensation can be an issue, but sheesh... I'd be surprised to find that you could collect that much over such a short period of time. If it turns out to be simply condensation, then the fuel in mine is suspect right now! Here's to hoping you get some closure!!

Yeah, really. That's a lot of water! How did that happen?

I'm gonna go a little bit further with the engineer stuff and ask... Are you guys really sure that it's a BSPT at all? Have you checked yourself? Does anyone have corroboration from anyone who has actually checked? Does someone have a spec drawing for the oil pressure sender? Are we really really sure that it's a British spec in the first place? I've heard this BSPT thing here a whole bunch for the plumbing fittings, but personally... I'm skeptical. Haha!! Clear your conscious? Sounds like you had one too many?

Flare style check valve not your thing? Here's a banjo style alternative I've worked through. This one uses a 12mm banjo style outlet. Bosch part number 1 587 010 536 Bosch part number 1 587 010 537 And along with either of the above, you'll also need a 12mm x 1.5 sealing cap nut: Bosch part number 2 915 142 018 or Mercedes part number 1239900053 Here's a pic with the original valve up top and banjo style on bottom. Again, notice that the alternate is too long on the fuel pump inlet side: Give the pump inlet end the same cut off treatment: Again the trick is the different style outlet end. For this one, grab a 12mm banjo style hose off a junker. I grabbed one off a Honda Civic since just about half the cars at my local yard are Civics. Here's the pump with the check valve installed and the Civic fuel hose laying next to it: Cut the banjo fuel hose off at the appropriate length: And put it in place. There might be other hoses that fit more natural than the Civic, but it failing other options, the Civic hose works. If you find something better, please post it up: The other trick with the banjo style is that you have to cap the end of the valve. Bosch uses 12mm x 1.50 threads, so buy an appropriate cap (or find one on a Mercedes in the junkyard). Unfortunately Honda uses a 12mm x 1.25 threaded cap so the Honda caps won't work: Here's the parts you'll need for the banjo alternative:

Haha! No, I guess not. Although, it makes the "I'm too far away" card just a little more valuable...

Chas, I got the O-rings and the install went fine. I'm kinda flitting around between eight different projects and it slipped my mind. I was also thinking that I wouldn't post much about it until I had put fuel back into the pump and made sure that everything worked as intended with no leaks and such. So at this time, the O-rings are in, but untested. I know... What could possibly go wrong. go wrong. go wrong.

If I weren't so far away, I'd be happy to come over and strip with you guys. Wait a minute... We are talking about a car, right?

I already know the results... It works great. I actually put it on my car for the first time near the end of last summer, but was in too much of a hurry to take pics then. I knew I would be back in there again this off-season, so I saved the formal documentation until now. So if you're waiting for testimonials about performance, then I've got that too. On edit - About the pressure bleed... Even with the new valve my fuel pressure bleeds off in a couple hours as well, but it's not the check valve. Mine is either the fuel pressure regulator or an injector. Small enough bleed that I've still got fuel pressure even after I've crested the heat soak of a hot start, so I'm not too worried about it. It's lower priority now.

Gotcha covered: http://www.classiczcars.com/forums/fuel-injection-s30/51862-fuel-pump-check-valve-alternatives.html

The original Bosch fuel pump check valve is NLA and I've been messing around with alternatives. The original check valve has a 10mm x 1.0 threaded inlet and a barbed outlet to accept an 8mm hose. Can't get it anymore... There are other Bosch check valves available with a 10mm x 1.0 threaded inlet, but the outlet styles are different. Not a problem! Here's the first alternative I've worked through. This one uses a 14mm thread taper seat style outlet. Bosch part number 1 587 010 539 Here's a pic of the stock check valve on top and the 539 on the bottom. Note that the pump end threaded portion of the alternate is longer than the original valve. It is so long, in fact, that it will hit the armature inside the fuel pump if inserted all the way: First, you have to deal with the longer threaded portion before you can screw the valve into the pump. If you don't you'll mess up the insides of your pump. I cut off a couple threads to shorten it. I used my lathe (because I have one), but you could just as easily use a hacksaw or file. Just make sure you pack the hole with some paper towel or something so you don't get metal chips inside the valve. If you can't deal with making it shorter, then you could just stack up a couple extra copper washers to take up the difference. Here's a shot of the valve after I shortened the pump end threaded portion: Now about the outlet end. Here's a shot where you can see the tapered seat on the outlet end: How do we deal with the outlet end? Easy... Just grab a fuel rail hose off a junked Audi. I didn't get the year or style, but they were easy to come by. I think a couple Audi models (and maybe even VW) used the same hose. Here's the alternative valve installed in the pump and the Audi fuel hose laying next to the pump: You can get the hoses with the end attached with a clamp, or permanently crimped on like I did. Here's the conical seat on the fuel hose that mates with the check valve: Here's another shot showing the printing on the side of the hose. Attach the hose to the valve and then loop the hose around and clamp it to the inlet of the dampener. Done. Cheap and still available. And easier to change in the future if necessary in the event that it goes bad: Only other complication was that the original hold down clamp for the original steel loop was too small to fit the Audi rubber hose through. I just used an appropriately sized cable clamp instead. When I get another chance, I'll talk some about a banjo style as an alternative. I got one of those as well.

And if you can't get that bump stop firmly against the back side of the lock nut, no big deal... It will be pushed into place the first time you steer to lock. The end of the rack will push it outboard.

Probably too late, but I wouldn't bother with that check valve from ebay. I bought one and it didn't last. Worked fine new when cold, but as soon as the engine compartment got hot, the hot fuel attacked the sealing disk inside the valve and potato chipped it. Didn't hold pressure after that. I've got pics of some of my alternate fuel check valve installs on the camera, but it's gonna take me a little bit to get them to the web and write something up.

Haha! I was hoping I wasn't the only other one to get that!

Timsz, Yup... That part without threads is an end of travel bump stop. So the order you've got the parts assembled in your pic is correct. Tighten up the end rod until it stops turning and is bottomed out on the end of the rack gear and then snug up the lock nut to keep it there. Then slide the bump stop(s) outboard until they are up against the inboard sides of the lock nuts. So when you bottom out the end rod, does it sustain it's own weight, or is it floppy hanging even when fully tightened? Funny that they never mentioned or pictured the bump stops in any of the manuals...