Zed Head

Is this the one Dave? More interesting to talk out here. Somebody else might know something. The bearing and spacer must have been in the vicinity when i took it apart Maybe the spacer positions the small gear to match the other gear, and that's where the noise is coming from. You might need the spacer too.

A new dealership might have to order it. And if they have new parts guys you might have to give them the part number. Or you can get it from Courtesy Nissan. It's been superceded a few times. http://www.carpartsmanual.com/datsun/Z-1969-1978/engine-280z/cylinder-head/41 https://www.courtesyparts.com/?p=catalog&mode=search&search_in=all&search_str=21200-V0100

I'd get a new Nissan thermostat from your Nissan dealer (I got one a few years ago, I think that they're still available) and install it as-received, no holes drilled. It's the most unknown of your unknowns. The boiling test doesn't really tell you much except that it opens at 212 degrees.

It's been discussed before but there doesn't seem to be a clear and easy solution. Looks like it's some sort of custom Nissan thread size. You might try an EGR tube fitting from another manifold and block the tube with a compression fitting or brazing it shut or similar. Here's a past discussion, no solution found -

Is it an autoscaling meter or do you choose a scale? It's just a three position switch, that produces very low resistance (continuity) or very high resistance, on certain circuits. The beeper function on a Fluke or similar might be a better test. You might be getting too far in to fine details. Were you using the 1980 book, and the tests shown for 1979 and later? Can't really tell what you did.

Over here we would never pay for a car without the title or a form from the buyer stating that they had lost it. Edit - or a Bill of Sale. You should contact the seller for those documents. I'm not sure how they shipped it without having them. The shipping company might have copies. They would need them to show that they weren't shipping stolen goods, I'd think. I just did a quick search and found this. I'd contact the seller to get the documents that should have come with the sale. Edit 2 - re-reading what I posted, it looks like the shipping company carries those documents with the car. They should have given them to you. https://www.wcshipping.com/europe

Seems like this particular buyer might have bought it as a car, to drive and enjoy, not a collector item. Nothing wrong with collecting. The videos on the BAT site give a good impression of looks and sound. It is odd though, since the engine "rebuild" was just a hone, rings, a new timing chain, and some seals. And the AC isn't hooked up so even driving it is limited to cool weather. Maybe they just like silver.

What documents did you get with the car? Over here, the two common documents to show ownership are the title and the registration document. Who is asking for the "certificate of origin"? You should probably ask them what they mean by that term. "Origin" could mean where it was shipped from so could even be a shipping company document. I doubt that origin means Japan. I'd bet that they need shipping documents, to show that it came from the USA.

Pretty sure I've seen people write about it. I seem to recall spacers being discussed. Are you really in India?

The big hose is T'ed with the idle speed control air bypass. So a simple plug at the end of the hose or at the mechanism itself should work . Looks like the bypass feeds directly in to the intake manifold. Follow the air flow path from one side of the TB, through the screw controlled idle controller, and to the intake manifold to be sure. You need to be aware though, that removing the BCDD will bring back the original problem it was meant to fix. You'll have a gassy smelling car if you coast to a stop while in gear. You might end up wishing you had fixed it. The 81-83 ZX's have a mass of vacuum controlled devices that can leak. Here's another. Which brings up another reason for idle speed to increase - ignition timing. You might have a sticky vacuum advance mechanism n your distributor. Pretty common. There are are also thermally controlled vacuum valves placed around the engine. Can't remember how many.

I have a ZX manifold in the garage if anyone needs a BCDD.

I thought that the plate would go directly on to the manifold with all of the hose connections removed. But I think I see what you're showing now. Those hose connection is still there. Nissan shows an interface. I wonder if that piece can be removed and plated there.

The FSM picture looks pretty clean. It's probably where the hoses were connected. But you do also need a good solid seal on whatever blockoff plate you attach also.

You can check for the stuck throttle blade by pulling up on the pedal with your foot or manipulating it by hand under the hood. There are two return springs, one on the TB itself and the other attached to the linkage. On the ZX engines I think that the linkage spring is very visible, right on top. I snipped ypur picture and drew an arrow to the spring and linkage, Make sure it's free and working right. Also arrowed the ZX idle adjustment screw. It works by letting a small amount of air past the throttle blade. If you figure out the excess air problem you'll still have the goofy ECU problem. That could be a loose connection or a bad ECU. Is it a ZX ECU or the original Z ECU? They're different. Should be next to your left foot, behind a panel. With a sticker on it that ID's it. Take a picture of the sticker. It's probably the Z ECU and they are known for failing like yours is, with the tapping it rich/lean problem.

I've only heard of Nissan and Subaru using the R180. Maybe he meant Datsun 4x4 pickup. The Toyota 4x4 disc brake calipers are used though.

Engine speed is controlled by the amount of air it can get. It's always trying to get more. So if you want to reduce engine speed you have to reduce the amount of air available. The quantity of fuel available will only control the quality of the engine speed, not the quantity. The quantity of fuel in a gasoline engine is always match to the amount of air, to control the qulaity of the combustion. So, your first task should be to control the quantity of air getting in to the intake manifold. The throttle blade should control almost all of it, especially since the BCDD is gone. One area that people tend to miss is the PCV system. It is connected to the intake manifold and the engine's crankcase. So any air that gets in to the crankcase, like through the valve cover, can get in to the intake manifold, and cause a high idle. Normally, extra air would cause some increase but a little more would cause a decrease as the mixture gets too lean. But, if the ECU or FPR is allowing extra fuel, the extra air can cause the idle to rise a lot since there is extra fuel to go with it. The PCV diagram in the Emissions chapter is worth studying. It will give some ideas about where excess air could be getting in and which hoses to plug or connect properly.

It will work but the 280ZX starters have more torque, I believe. They are gear reduction starters. The cone nose is a 240Z to 280Z type starter. It's a regression. You can use 280ZX starters on Z's and vice-versa.

I think that the pins are held in place by the sides of the bowl. Once assembled they can't get out. Have you examined the valve itself? As I recall, they're typically a rubber coated pointy piece that sits in a precision ground hole. The float presses it in to the hole as it rises. The rubber can get hard or take a set or have a groove worn in it over time, and not seat properly anymore.

The oil would have come from the PCV system. Nissan redesigned the PCV hose routing in 1977 to avoid blowby fouling of the throttle body. I'm pretty sure the CO has been in to the BCDD machinations, and that siteunseen has "tuned" his for better operation. They might have some suggestions.

Not sure what you mean by "dry" but I would only use a small amount of sealant around the edges of the diaphragm, if any at all, if it looks like the rubber won't seal. The device is only meant for air to pass through and be diverted to desired places. Also hope that you marked your starting points so that you can be close to correct adjustment when you put it back together. There is at least one thread on the site about adjusting the BCDD, even though Nissan says to never take it apart, just replace it. @siteunseen @Captain Obvious

Really nice car. But, it's not "restored". Restored means taking it back to original condition. Not sure exactly what a better term would be (resto-mod sounds kind of goofy), but restored is going to draw a different type of looking-to-buy type than what you're selling.

That's a fuel pressure gauge. 5 psi might be a little high for Webers, but I don't know Webers. Float bowls and valves are all similar though and 5 seems a bit on the high side. AFR stands for Air Fuel Ratio (even though air actually contains fuel) and AFR meters are used to help make adjustments to hit a certain fuel air ratio. But the old school ways will work also. No offense Travel'n Man. People have tuned many carbs before AFR meters came about. They're great for fine tuning but he can make a lot of progress just by eye, and butt, from where he's starting.

I should say that failing valve guides is not a bad guess, although seals would be more specific. They will leak more oil at idle under high intake system vacuum and dirty up the plugs pretty quickly. Then when you start driving much of that will burn off. My original engine had bad seals and would run rough after putting around town, then would clear up after I gave it one of those high rev tune-ups. It was fun for quite a while to have a reason to go beat on the engine, trying to figure out why it ran so much better afterward. After I removed the engine and took the head off, I noticed oil draining down the intake and exhaust valves after just a little while. The seals weren't sealing at all. There's quite a bit on the site about changing valve seals. Pretty easy, I think, and might make a big difference. In short - I second madkaw's thought, in Post #2.

That's quite a write-up. I was thinking of your other article when I mentioned that something might be in the Technical area.

This site is supposed to be based on actual sales. Pretty sure they start with a a running engine and drivable car though. Your money... https://www.hagerty.com/apps/valuationtools/1978-datsun-280z https://www.hagerty.com/valuationtools/Classifications-and-Conditions https://www.hagerty.com/valuationtools/About-our-prices