Captain Obvious

Crap. I knew that was gonna happen. Maybe next time I'll sign an affidavit stating that I didn't it? That would work, right?

Yeah, I'm going to walk back my thoughts a little on this one. Chickenman is right that the stakes are pretty high and if there's any question at all about it being risky, then it's best to replace parts to tighten things up. My assumption earlier on in this thread discussion is that it is the correct thread, but just maybe a fit class a little looser than expected. However, without actually seeing the parts with my own two eyes, my assumption is just that. And it carries all the risks that any assumption carries. For all I know, it is NOT the correct thread, even though it engages without excessive force, Unfortunately, I cannot tell that for sure without actually seeing and measuring the parts. So if you're unsure about it and don't have anyone local with suitable expertise who can look at the parts and pass judgment, then you should probably replace parts.

Well that could be an issue! IMHO that would fall into the category of "Unless the threads are so loose that you're worried you'll actually pull the outer tie rod off the inner". Let's not do that!

Oh Long Johnson! Oh Long Johnson!

The I Robot reference was philosophical. The robot who saved the lead character's life many years before. Calculated the odds and options, crunched all the numbers, ran multi-outcome scenarios... And then after all that, made a decision that wasn't human. The "logically correct" decision, but it was still wrong. And we are still light years away from being able to have even THAT level of sophistication. Kid and his dog run out into the street and unfortunately you have to hit one or the other. Lose contact with the satellite for even just one second. That's 88 feet of travel on the highway. EMI interference from the construction worker who just keyed his walkie-talkie on the side of the road. Skid and/or spin recovery and mitigation. Swerve into oncoming traffic, or dive for the shoulder? They can pull my steering wheel from my cold dead hands.

Captain Obvious is compelled to point out that you already got two opinions. Mine, and confirmation from the tech support from MSA. Seriously though, however you proceed is up to you. Personally, I hate sloppy threads.

I never said that.

Checking the AFM with resistance like that doesn't really work. The black saw tooth shaped thing on the AFM circuit board is a resistor. And it's resistance follows a similar saw tooth shape. That's what you were seeing on your meter. You need to check it hooked up to a voltage, and check voltage not resistance. I think @Dave WM posted a video showing that method? And if not, I'm sure he'd be happy to put one together?

It's that movie 'I Robot' in real life. The computer will never-ever be able to do what a human can in every situation. Either conceivable, or unconceivable. I honestly can't believe the whole self driving car has gotten this far in our litigious society. Bugs happen. Surprises happen. Hacks happen. Who is it that's pushing hard for this to become reality in the first place? Liability lawyers?

So she's stuck working on your engine while you went out for a bike ride? Thats not very nice!

I've messed with it a bunch. Couple years ago Blue and I also measured the mixture effect that screw caused. He gave my car a rectal and monitored the mixture numbers while I changed the screw setting. I've got notes around here somewhere, and when I put my finger on them, I'll post them. And I'm not surprised that screw did not have a direct effect on manifold vacuum. That screw is upstream of the throttle plate, and while it might result in a tiny tiny change in flow resistance, the majority of the vacuum is going to be developed across the plate in the throttle body. Sure, messing with that screw could 1) change the mixture, which in turn could 2) change the RPM, which might 3) change the vacuum reading... But not a direct "flow path restriction" related effect.

I got info. Lots! Of course most of it is completely useless, but I got lots of it!! Happy to share!

Maybe that part of the documentation was instructions on how to dispose of the old struts? Drill a small hole to release the pressure first, and then chuck them. I hate the international "icon only" based instructions. I wonder if they make sense to people in other parts of the world, because they certainly don't make sense to me at this part of the globe.

I was wondering the same thing. I don't think that's OEM. z boy mn, What makes you so sure that bolt was grade 10.9? It has the grade marked on the head? As an aside... I verified the FSM spec, but 50 ft-lb sure seems a lot for a bolt that size.

Actually the factory carbs for your 74 were "Flat Tops". Many people replace them with other carbs like the "Round Tops", or Webers. Which ones are you interested in hearing pros and cons? Because if it involves Webers, I'm not your guy... I know nothing about them.

Increasing the resistance increases the fuel. And there's absolutely no way you should need an additional 1K worth of resistance to get it to run right. There is something else way wrong somewhere else that you're trying to compensate for with that resistor. No way, no how.

I figured that was gonna happen! I was thinking of you when this thread popped up!

The link to 240zlover777 came from the original auction that started this whole thing: https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F123002344687 Back when this all started, that auction was under the name whitelotus909, but if you take a look at it now, it's listed under the name 240zlover777. And you know it's the same guy because the negative feedback from nix240z is there and the auction number is the old one:

I'd hate to have that thing wiggle under use too. That would be bad. I believe however, that if the locknut is doing it's job, that shouldn't happen. Good luck however you proceed!

Glad to help. My pleasure I would take the opportunity, however, to point out that even the simple 240 had the exact same feature. It just looked different. The "Throttle Opener" system on the 240Z's is the exact same thing as the 280's BCDD system. Does the exact same thing... Limits intake manifold during high vacuum deceleration conditions. So your 240 has it too, they just called it something different, and they didn't hook it to the speedometer. And now that I think about it... I believe they started hooking the throttle opener system to the speedo in 74, so that speedo may be suitable for the 260 as well as the 280s. TMI?

Me too.. I wouldn't worry about that. Maybe hit it with some 600 grit to make sure there aren't any burrs kicked up from the scratching, but other than that, I'd go ahead and leave it.

Of course! Haha!! The BCDD system is part of the emissions system on the 280's. It limits the intake manifold from going sky high under deceleration and making the mixture go all wonky (technical). It limits unburned hydrocarbon under deceleration. The system is only activated once the vehicle speed is above 10mph, and they detect that threshold using the speedometer. There's a tiny little switch inside the unit and that white electronic nubbin (technical again) on the back is an amplifier that takes the signal from the tiny switch and boosts the power allowing it to control devices that need more power than that tiny switch could provide.

I'm sure you probably already know why this happens, but just in case... There are no real seals on the seam between the nozzle and the cylinder in which it slides up and down in the carb body. You don't really need a seal there as long as it's a good precision fit. Sure, it'll leak a tiny amount of air up through that seam when the engine is running, but not enough to matter. Also, under normal circumstances, that seam never sees liquid fuel. But if the bowl level is high enough, and the nozzles are pulled down far enough, that seam will be exposed to liquid fuel. And it's not meant to be liquid tight. If there isn't engine vacuum to pull that fuel up, it'll leak down (as you found out). Natural gas water heater?

Perfect! Sounds like me. I'd much rather be up to my elbows in anything mechanical or electrical than anything to do with bodywork!

It's a 280Z speedo with the 10mph dropout detector for the BCDD system. Oh, and it does have numbers on it. It goes from 10 to 160 just like all the others.