Captain Obvious

Haha!!!

And there you have the difference between the man of few words... And me.

That's your "EGR Relay". It disables the EGR system and retards the ignition timing until the engine has warmed up enough to trip the water temperature switch. That relay and the water temp switch are both located on the wiring diagram in the lower left behind the headlight (kinda like where it is on the actual car). The EGR function portion is described on page EC-16 of the manual and the ignition portion is described on page EE-27.

I did some analysis of my old red links. I have no idea if they are factory originals or not, but they sure look old enough that they could be. With that in mind... The insulation OD is 2.8mm (.110 inch), which does NOT fit cleanly into the Yazaki datasheet. There are five strands of wire inside the insulation. Each strand measures approx .28mm diameter ( 0.11 inches ). If you do the math... Each strand has an area of approx .062mm sq and five of those all together is 0.31mm cross sectional area. So it appears to me that the old red links are pretty much the same cross sectional area as the new brown links. The insulation diameter is different, but the conductor cross sectional area seems right.

If I get a chance, I'll pull my EFI link out again and measure the OD. If all the theorization holds true, it should be about 3.0mm OD on the outside if the insulation. On edit... Couldn't stand not knowing! Just pulled it and checked. My green EFI link is spot on 3.0 mm (0.120 in) diameter. Another data point to support the belief that it is a Yazaki FLWX 0.5 (0.56mm cross sectional diameter)

Hmmmm... I have no idea. I do know that different manufacturers are not bound to color conventions, so "green link" from one company may not be the same rating as a green link from another company. That also means the what used to be a green link from the factory on the Z could be electrically equivalent to a black link from a different manufacturer. And I have no idea where Bonzai is getting their materials from. Here's what I DO know... 1) Pretty much all of the electrical infrastructure (connectors, contacts, etc) came from either Yazaki, or AMP. You can find one or the other of those two logos on pretty much everything. 2) The fusible link colors and cross sectional areas listed in the FSM's line up exactly with Yazaki's datasheets. 3) The new fusible links purchased from Nissan have Yazaki's name and numbers on them. Those three facts have me convinced with a high degree of certainty that all the original links all came from Yazaki. And if that's true, then the green link is from the Yazaki FLWX series and is 0.56mm square in cross sectional area. So... Getting to the point (there is a point...). If that black link from Bonzai is 0.56 mm square, then it should be pretty much the same as the original green Yazaki link. But I have absolutely no idea if that's the case. Maybe Bonzai would answer some questions if asked?

So I snapped a couple more pics of the 75-77 fusible link for the EFI system. A little background... the 75-77 EFI system has it's own dedicated harness and the only connections it makes to anywhere else anywhere on the car is in one spot above the driver's knees where the EFI main relay is located. The 78 is a little different and has the EFI relays up in the engine compartment and I don't know if they use the same dedicated harness for 78. But for 75-77 inclusive, the EFI fusible link looks like this. Green in color and includes a thick plastic strand for strain relief (that's the white part).

No.

Thanks for that fresh pic. That's a good one to get a handle on the wire colors for 76. Even without putting a meter on your 76, I have high confidence that your labels are correct and the link colors shown on those labels would be appropriate. If you take the two link blocks on the 76 FSM diagram and swap the two, then the FSM matches up with the car. I think they did the first screw-up in 76 and then ported that mistake in the documentation to 77 and 78 as well. The two white wires on that front block are larger than the one side of all the other links, and that makes sense. Same as 77. Only difference is that in 77 they made the wire colors a little more straightforward and didn't do as much "color changing with splices" inside the harness. And thankful for that!

grannyknot, That thing you pictured below? I don't think that's the EFI fusible link. The fusible link for the EFI has connectors on both ends and one end plugs into what you show here while the other end plugs into a wire that leads to the EFI system. The only pic I currently have of the EFI link from my car is pretty crappy. I can tell you, however, that on my car it's green in color. So if one is to assume that all the fusible links came from Yazaki, then it would be the FLWX-0.5 green wire. Here's what I have. Note that it looks like there are actually two wires, but in fact, there is just one. The other white thing is a non-conducting plastic string between the two connectors. Presumably a strain relief so you don't yank on the fusible link itself:

About the 1976 stuff.... If you look closely at the wire colors and the diagrams, you can see that the 1976 stuff is all kinds of screwed up too. In this pic, from a very well kept unmolested 76, you can see that the front block has (at least) two W/R wires going to it, and the rear block has (at least) three: Some of the wire colors and positioning are confirmed by Zed Head's previous pic as well: So with that in mind... First thing that can be deduced? The 1976 color wiring diagram floating around out there is wrong. Here's the previous snippet that shows four white and four W/R wires going to the link blocks (like the 77), but the photos of actual cars clearly show different: The next thing that can be deduced is that the factory wiring diagram suffers from the same link block positioning issue that exists for 1977. If you trace the circuits and then compare them to the links on the cars, you'll see that they have the link positions wrong in the 1976 FSM. They have the blocks reversed on the FSM wiring diagram: The only thing that seems to have made life easier than the 77 owners is that the stickers on the links themselves seems to have been of better quality and lasted longer than the labels from 77 and 78. Maybe Datsun changed their label manufacturer and went to cheaper labels that didn't last as long. The other thing that made life easier for the 76 owners is that the creator of the color diagram for 1976 put the link COLORS in the correct geographical locations even though they are in the wrong ELECTRICAL locations on the diagram (did I say that right?)

Haha! Nice pic. I'm guessing it's Bigfoot. Maybe Bigfoot wearing a button down shirt because he's going out to a nice place for dinner with Ms. Bigfoot?

Thanks for the additional info Joseph. Relieved to hear that I had not been spreading incorrect info about the link positions. And I agree... I think either the color positions in the factory wiring diagrams was wrong from day one, or the workers on the assembly line put the link blocks in the wrong positions. But since we have seen the same positioning on five or six 77 and 78 cars, I think we can assume they were consistent. Are you going to create a new picture for your website, or are you just going to recommend that customers confirm the position of the largest R/W wire and tell them to put the black link there?

Wow. Never would have guessed! Cool!!

Hi @Joseph@TheZStore, Thanks for chiming in. I dug out my old 77 links and took a look at them as well. My findings are the same as yours... They are red, and they are thicker than the new brown links. I also believe they are from Yazaki, but are from the thicker FLWX series. The question remains "Why?", but I doubt we'll ever get to the bottom of that. So how about the link positioning? Did your stored 1978 have the thicker black link towards the front of the car, or was it located towards the battery? Also, were the original label stickers on the link blocks still legible? I'm especially curious as I've been the one championing the "Nissan screwed up the positions in the documentation" argument. I'd hate to find out that I screwed that up and have been propagating mistaken info in some way. Thanks again, and hoping you can add to the discussion.

Hmmm.... Are you double dog sure that your 260 is really really 12/74? Looking at your door jamb nameplate, it looks like 1/74 to me and what you are considering a "12" is caused by some "two shaped" scratches on your nameplate. I'd be hard pressed to believe they were still making 260's that late in 74. I'd also be hard pressed to believe they were making 260's and 280's at the same time like that. Are you sure that's a "2"? If you look at the serial numbers, there are like 130 thousand cars between those two plates. Something seems amiss. As for the weight difference... That's the GVWR. Maybe they were assuming the passengers gained 20 lb each.

Definitely keep us posted. It's an interesting project. Do you have a micrometer? I've tried a couple different measurement devices on needles and have found a good ol' micrometer to be the best of the bunch. Most accurate and most repeatable.

Gotcha. If I were closer, I'd be happy to lend a hand. Problem is, this is going to be a "take a little off and try it... Take a little more off and try it again" kind of affair. Tough to do with two days shipping in each direction. One thing you can to do to help yourself out is figure out where you are on the needle when at WOT. By that, I mean... When you are at full load and the suction pistons are pulled all the way up, there should still be some needle sticking down into the nozzle. You could push the piston all the way up by hand and reach into the carb throat with a marker and Sharpie mark on the needle where it enters the nozzle hole. Then you would know where to concentrate your metal removal efforts. If you are running lean at WOT, you would want to concentrate your efforts where the WOT needle enters the nozzle and a little above and below that.

Yeah, the advantage to spinning the needle is a probability for increased uniformity. I do enough metalworking that I feel like I could just "wing it" if I didn't have access to machines to help. Maybe lock your hand drill in a vice? Do you have a vice big enough?

That is where the needle is supposed to be installed. If you had it pushed up flush with the groove in the piston, then you had it in too far. You can do all the needle modifications by hand. You don't really need a drill at all. You're only looking to take off one thousandth or so.

I get a little lost with most of the "updated redesign" results of most cars. Including the Z. There are people that say they see the first gen Z in all of the revisions that came after the 280Z, but I'm not one of them. I "get it" with the ZX and can clearly see the lineage, but after that, I lose it. I see no original Z in anything that came after it. Not to say that some of the successors aren't nice cars, but I just don't look at them and think 240, 260, or 280. Lately though, there have been several manufacturers closely following the original visual design with a brand new car. Like the new Mustang, the Challenger, the Mini, etc... IMHO, they all represent the original visual design very well. So all that makes me wonder what would happen if they tried this:

It's fine. Just bolt it on!!!

Yeah, I remember that metaphors episode. My work buddies and I spent the next couple weeks talking like that after that episode aired. Drove our boss nuts (since he didn't have any idea what was going on). Sitting in a meeting, nodding approvingly..... "Nancy at the Christmas party."

Really? They used the same window in both the old Rockford Files and that X-Files episode*? Did you actually remember that, or did you figure that out somehow? I would have a new level of respect for you (if that's even possible) if you remembered that just from watching those two shows!! * Hungry - Rob Roberts works at Lucky Boy and eats brains. I love the part when he's at the OA meeting describing his issues to the other attendees.

No, there's a rolled over metal beaded edge. I chucked it up in a lathe and cut the bead off just as exploratory surgery. Sorry if I gave you any false hope. It's an autopsy.