Captain Obvious

Yup. You got it. You are now using the "78 scheme". Your throttle body will still be a mess, but your AAR will thank you.

I will wear my new mini-mag-glass with care. Not sure what you consider "early" Z, but I've found a mistake on the factory diagrams for 74 (and maybe 73... don't remember) temp switch wiring. If you're doing anything with those docs, let me know and I'll provide details.

No apologies necessary! None!! This document is fantastic, and even counting the tail chasing this time, this document adds so much value that I'm way ahead of the game! I'm not aware of any other issues at this time. Thank you!! I applaud all the efforts, and I'm just glad I could help make an already fantastic document a tiny bit better.

I think I have retraced my steps on where I first found copies of the color wiring diagrams... I think I first heard about both 77 and 78 here: http://www.classiczcars.com/forums/thread44992.html But the 77 version appears to have originated earlier here: http://www.classiczcars.com/forums/thread13131.html So from the above two threads, it appears that wal280z did the 77 version back in 2004 and awolfe did the 78 version in early 2012.

I picked up this diagram some time ago but unfortunately I don't remember the thread that originally turned me on to it. I'm pretty sure that it was on this forum though. I believe (especially because of the ClassicZ mention in the legend area) that the owner of the document hung out here. I was hoping that he would pop up... As for the problem that I chased? It's in the fuse block: For comparison, here's a snip from the 77 FSM: Important to not also that the 78 color diagram is correct. It's just the 77 that has the problem.

Very common issue with our L-Jet systems. Search around here and other Z sites and you'll find lots of people with the same problem. Lots of band aid solutions too as well. As for whether it's rich or lean? The common belief is that it's running lean.

The vacuum control lines only exist on the cars with A/C. The non-A/C cars are completely cable actuated mechanical only. That's why I asked if the car had A/C or not. I'm not sure what lines he's talking about here. I'm not sure if he's talking about the vacuum control line to the ON-OFF A/C derived water ****, or is he mistaking the hard copper line to the temp control valve for a vacuum line? In any event, I'll jump to the end of the chase here and say that I've recently messed with my system, and it all depends on how small your hands are and how long you can work while laying on your back with your head up under the dash. I don't think there's any vacuum line that you cannot get to if your hands are small enough and you are flexible enough to deal with the contortions. However, I've decided that if I ever have to do major work to the heater system again, it would be easier to just pull the dash. It's just not that hard to pull it, and working on anything heater related after that is just so easy that it's not worth it (for me at least) to try to do anything significant with the dash in place. Here's my bottom line... If you've got one tube that is leaking and you want to address just that one, then maybe preform the contortions. But my guess is that if there's one that needs to be replaced, then there are probably several others that should be as well.

I picked up a color wiring diagram for 77 on the forum here somewhere... Is the owner of said document still around? I've found some mistakes. I just spent two hours chasing my tail and I want to prevent anyone else from doing the same!

Now that's something interesting that I never played with... Who knew? (Probaby everyone but me)

Bruce, Let me see if I can help. What's going on here is that he fills the dampers up to (and not above) the fill-to line scribed into the stalk, drives around for just a couple hundred miles and then checks the levels again only to find that the level has dropped significantly below the fill-to line. He has stated that he is not overfilling the tubes to capacity and then displacing fluid up and over the top when he puts the stalks in. What makes the situation interesting enough to warrant two pages of forum is that he is not overfilling the dampers and then wondering where the oil went... He's filling them to the correct level and then wondering where the oil went.

Are you talking about the vacuum control lines (which only exist on the cars with air conditioning), or are you talking about the hard copper line that comes out of the top of the water control valve? (Or something else completely?)

Haha! Lucky shot! I had my eyes closed to boot! If you do what you described above, then you will end up with exactly how Datsun did it in 77. The only difference would be the existence of the (unused) nipple on the accordion boot. Would that fix your oily throttle body? I don't think so. Other than reducing the blow-by as much as possible (by engine overhaul work), I don't think there's anything you can do to get rid of it completely. You need to plumb that PCV vent tube to the atmospheric side of the throttle plate somewhere... There's just no way around it. Many newer vehicles run that line to the dirty side of the air cleaner, but because of the way the air metering is done with our L-Jet system, that's not an option for us. However... Even though it wouldn't fix your oily throttle body, it would be simpler. The plumbing scheme you've currently got I consider to be the worst of both worlds. You've got the extra plumbing for the 78, but because of the way you have things routed, you aren't getting the benefit of a clean air stream for your AAR. You've got the dirty valve cover tube still going upstream of the AAR and the throttle body. I'm thinking that you can make it simpler by doing what you proposed and going back to the 77 scheme. You won't see a cleaner throttle body, but at least it's simpler. My thoughts on the 78 routing is they didn't do anything about oil in the throttle body, but at least they managed to clean up the AAR. Does that make sense? Do you understand the difference with routing in the 78 pic I posted? in 78, Datsun has the valve cover piped to the throttle body and the AAR piped to the accordion nipple. You have the valve cover piped to the accordion nipple and the AAR piped to the throttle body.

Haha! I'm really sorry... I still can't figure out what you're trying to accomplish, so I'm gonna shoot in the dark and hope I hit something valuable. They changed some of the PCV and AAR air piping between 77 and 78. In 77, it looked like this (sorry for the crappy pic). They pulled the air for both the upper PCV tube to the valve cover and the AAR off the same point on the throttle body. That point is just on the upstream (low vacuum) side of the throttle plate inside the throttle body: In 78, they added a rubber nipple to the flex boot on the intake side of the throttle body and split up the air intakes for the PCV from the AAR. The PCV still got it's air from the same place as 77 (upstream of the throttle plate in the throttle body), but they moved the air intake for the AAR farther upstream to the new rubber nipple on the flex boot. The boot is missing from this pic, but at the very bottom of the pic you can see where the metal tube leading to the AAR would connect to it: I've not got any real info on the reason they made that change, but I would speculate... On my 77, I get a lot of crud that comes out of the valve cover and through that upper PCV tube. I don't know if I've got too much blow by for the PCV to handle or what, but all I know is that it's dirty. So in my 77, I've got this dirty air stream coming off my valve cover, only to be sucked back through the AAR into my manifold. My AAR doesn't like the dirty air and gets really cruddy inside as a result. So my speculation is that Datsun figured this out, and in 78 they changed the piping to split those two sources and moved the AAR intake farther upstream into cleaner air so it doesn't pull through all that crud coming off the valve cover. None of this stuff will have anything to do with how long it takes your engine to warm up. If your AAR is dirty inside from breathing sticky oily residue from the valve cover, then it may take longer than it's supposed to for your AAR to close. Won't take the engine longer to warm up, but it may take longer than normal for the idle to drop. So, like I said, shooting in the dark, but hoping I hit something!

What's the question? What do you want an opinion about?

Yes! Exactly! I had the door panel off my Honda not long ago and I saw that same stuff. Sticky enough to hold at first and still somewhat tacky years after, not a sticky spreadable gooey mess like that butyl I spent so long cleaning off everything. I was thinking of asking if anyone knew what that stuff was, but wasn't sure I wanted to pollute the Z forum with a Honda question.

I haven't looked hard for other options, but the only version I've ever seen available for download is at http://www.xenonz32.com/reference.html.

Thanks again Jim. Your stated advantage for the cast iron manifold is exactly one of the reasons I'm considering going back. Less heat in the engine compartment is another one. I suspect most people would think I'm nuts to go back, but I seriously doubt I've got any performance gains with the header. Only advantage I think I have is the "coolness factor". As in "Cool! You've got a header in that thing!". I'm so past that... I've got the stock manifold for my car. PO put on the header, but included the old parts in a box. I was just thinking that if I was going to be putting on a cast manifold, it wouldn't be any more difficult to put one on that already had a bung built in (like 81 and up NA). And I could put a bung in the exhaust pipe, but I always thought the closer to the engine and the hotter the better?

Right. That's because the valve won't do anything until it's submerged. The point is, however, that having a good air seal above the valve is a red herring. Here's a way that you can feel the effects of valve misalignment: Fill the damper tube to it's proper level and then insert the valve stalk and push straight down on the screw knob until the threads contact the top of the body dome. Once the valve is submerged, you should feel the resistance caused by the properly closed valve (just like you described above). Then pull the damper completely out and repeat the same procedure, only this time jiggle the damper stalk side-to-side as you as you push it down. You should find that the amount of force required to push the damper "home" is less. The reason is that when you shift the damper stalk from one side to the other you misalign the valve's sealing washers and it cannot properly seal with that much misalignment. I'm a big fan of pictures too, and I'm sorry that I don't have any to help describe that process. Hope the text makes sense.

Thanks all for the additional suggestions. Wade, I was thinking about the hot glue gun and I got a couple questions. 1) Did you have any problems with the glue melting the plastic sheet? 2) You said "its removable", but I'm not sure what you mean. When you pull the sheet back off the door again, where does the hot (now cold) glue go? Does it stick to the sheet and come off with it, or does it stay stuck to the door metal? Blue, Does the cured latex caulk come off the doors easily if you have to do it again? I've used plenty of caulk in the past, but not on painted metal.

Thanks guys. I like the Peel-N-Seal idea. I didn't do a good job of explaining my dislike of the butyl as an adhesive... My PO had the door panels off and "refreshed" the plastic adhesive with fresh black butyl. He also replaced the rugs and used black butyl on the underside to help hold the rugs in place. In other words, I had fresh still sticky smearable black butyl all over the place, and every time I touched it, it spread. It was a *&%$# mess. The stock original butyl on the door plastics wasn't that soft and sticky though, and I don't know if it was simply a time thing or a different composition. There was absolutely no "curing" of the stuff my PO put on. All I know, is that I cleaned all of it off and I don't want to go through that again.

You don't need an air seal above that valve to make that work. It works simply on the hydraulics of the damper oil on both sides of the valve. Atmospheric air above that fluid matters not. Need proof? What happens when you drop the valve stalk into the piston? Does it drop quickly into place, or do you have to force it down into place before you get to the point where you can screw the cap in? If it's working correctly, you should have to force it down if you don't feel like waiting for it to drop on it's own. Without laying my own eyes on it, I would suspect that you are on the razor's edge of acceptable misalignment of the valve and that melted plastic goober was causing a tiny bit more of misalignment of the stalk, pushing you over the edge. I like the picture improvements. Makes it easy to see how it works when it's closed. The bottom cylinder pushes up on the washer above it which in turn contacts the fixed washer at the top. The beveled edges center themselves together and all the gaps close. The fluid then has to force it's way through the gaps which makes it harder to move.

I had to get to the inside of my doors... After I removed the door panel, I pulled the plastic sheet off the door. The sheet, being brittle from age, was unsalvagable. It tore in multiple places and needs to be replaced. Anyone know what kind plastic Datsun used for that sheet? I know I could just use a trash bag or a plastic drop cloth from a home improvement store, but I think the original was something more robust than polyethylene sheet. Also, how about suggestions of what to use to hold it in place? I cleaned off all the old butyl and I want to use something that isn't so much of a mess. Suggestions?

Thanks Jim, So the 280Z never did, but the 280ZX did? I found lots of pics of the ZX turbo manifold and that's not what I saw. The one I (think I) saw looked like the 240-280 manifold. I don't have the 81 FSM loaded, but I'm assuming the 280ZX NA version looks basically like the previous years? Wonder if it bolts right up to the later 280's... I would like an O2 sensor, and can't think of a better place than one that's already done. I could weld one into my header, but I'm thinking I might downgrade to cast iron. :stupid:

Did they ever put an O2 sensor in the 280Z exhaust manifold? I thought I saw a pic of a stock cast iron exhaust manifold that had an O2 hole cast into it, but now I can't remember where I saw that pic. I checked the fische and didn't see anything like that, nor did I see any reference to a sensor, but I'm no expert with the fische.

I did not notice any performance difference at the time, but I was fighting several fires at once. One of the other fires was that I was running rich under all conditions and that would mask problems with the pistons rising too fast. If I had gotten the fuel ratio down to reasonable levels and left the original misaligned stalk in place, I might have bogged a little when I punched it, but I never ran it like that. I fixed the stalk first and then fixed the mixture later. One thing I forgot to mention is that the stalks can tolerate some amount of misalignment before the valve fails to seal. But beyond that point, you run into a problem. Maybe you dislodged some dirt? Maybe a previous owner had it assembled incorrectly and you fixed it when you put it back together? Maybe you are right on the razor's edge of tolerable misalignment? In any event, keep an eye on it. Out of curiosity, have you had any backfiring through the carbs leading up to this? Not only is that a sign of a lean mixture, but the shock of the backfire can damage the stalk assy. I believe that's what happened to mine. BTW - I like your drawing of the valve bits. Missing a sealing chamfer on the underside of the top (fixed position) washer, but other than that, looks good.