Zed Head

Clean the T plug connection first. I've had mine lose contact and look like a dead alternator.

Look through the thread linked below. People think that's a big job. Compare to your cars.

By the way, the guys that are voicing their opinions about value aren't going to buy the car.

People want photos. Take a picture of the engine, and make sure you get the serial number stamped in to the flat spot below the #6 spark plug. Get pictures of the bottom of the car. Get pictures of the other sides of the cars that don't show both sides. Get better pictures of the insides. These cars are interesting but full of work. They won't sell themselves.

Fascinating how strongly people can feel about how other people spend their money. I'd get them running, shoot some clearcoat to retain the patina, and drive them.

That was a coincidence. A red herring, as they say. The condenser would have no effect at all if the wire was broken. You might have a short somewhere or a voltage regulator/alternator going bad. Your car has a voltmeter, not an ammeter, so what you saw was voltage dropping to 8, when it should have been 12+ or better. That's a sign that your battery voltage is low and that the alternator was kicking on and off. When it was on the voltage would jump to charging voltage, when it was off it would drop to the level of a dying battery with a load on it. Check your alternator is the short suggestion.

Some of these wires get hot and smoke? You have a lot going on there. The Start ignition system is different from the On ignition system, at the ballast resistor. I would check those wires closely.

Nissan thought there was a problem. They wrote a whole book about solutions in August 1975.

This might be of interest. Not much but more than just two hard to find years in one model.

How much (dollars) and how much (is included)?

Good luck. Always good to have a spare setup waiting when you're working with old parts. Is the spare distributor from a 280Z? Check under the cap to be sure. I think that a person could make that optical trigger work, with a separate power wire. It's a project for nerdy electronics types though. I'd probably try it if I had it in my garage.

You have an interesting situation now. You have the XR700 optical disc in the distributor, which uses a different trigger signal for the ignition module. It might work but we'd need to know what the XR700 optical unit puts out or controls. It might take extra wiring, and electronics knowledge. Some study is required. If you can find a 260Z or 280Z stock distributor that would be an easy wiring job. The stock units create their own voltage. If one of the electronics guys wants to take a stab at making an XR700 optical unit trigger a GM HEI module, feel free. The GM HEI module is often used to replace the turbo 280ZX ECCS "ignitor" which uses a 0 and 5 volt square wave.

The vented hood didn't show up until 1977, on the 280Z. One thing that I haven't seen tried is insulating the carburetor itself. There is lots of surface area, especially the domes, and it will absorb both radiant and convective heat. It's aluminum so will conduct that heat rapidly to the surrounding metal, down to the float bowl. If it was mine, because I'm not really concerned with appearance, I'd wrap some sort of insulation around that dome for starters. If it helps, consider insulating the bowl also. I've used that metalized bubble material on my EFI system and it works well. It's plastic (Mylar [PET], I think) but withstands the heat well except for the really hot spots, where it has crinkled up. Some zip ties and scissors and you're set for a quick trial run.

Have you seen this Nissan document? https://www.classiczcars.com/files/file/60-fuel-system-modification-plus-73-74/ Nissan turbos used fuel injection. But some still have heat soak problems with the injectors.

Wires getting hot when the starter is engaged could be a poor connection of the battery positive cable to the starter itself. The starter pulls a lot of current. Did you replace the starter with a new one or just another old unknown unit? You have a lot going on to try to figure it out without more details of what wires are connected to what. And your descriptions aren't making complete sense. You said the starter was spinning, but then said the switch had not been delivering power. How can the starter spin if it's not getting power? The switch only passes power to the starter solenoid anyway. The battery positive cable drives the starter motor. Check out the wiring diagrams and take some pictures of your starter connections and post them. Something might be obvious from a picture.

Can you take a picture of what's under the distributor cap? The XR700 used an optical trigger originally, but somebody might have kept the VR trigger. You need to know what you have. It might not be a straightforward swap to the GM HEI module. Sorry, I would have added more detail if I'd known you were going to try it.

When did they get hot? With the key Off, On, or at Start? Any chance you installed the battery cables backward? You need to give more detail than "difficulty starting" and "replaced some parts". Why did you replace the parts if you thought it was the reset button?

Seems to be missing a lot of parts.

He says in the text that the engine number matches...something. Incorrect wording but still seems to know. It's just a valve cover. He could easily add a picture of the engine number if somebody sent him a question, you'd think. " The vehicle has matching numbers (Engine/Drivers Door)"

Still 2601. Still interesting, maybe more interesting, just not the original car of the thread topic. Not 6230.

That says "similar item". It's 2601, for $9500 buy it now.

OReilly Auto has them for about $22. Just realized that there are zero Oreilly's in the Philadelphia area. Must be some mafia thing. Weird. But, the local auto mafia, whoever they are (probably the same crew that sells beer by the case from open warehouses), probably has some. They're not that NLA yet, I think. https://www.oreillyauto.com/shop/b/brake-systems-16456/brake-hydraulics-16513/wheel-cylinder-11318/5020ef8206ed/1978/nissan/280z?q=brake+cylinder

I meant mismatched as old versus new. CO has/had four cylinders, two leak and two don't. Or didn't. By the way I have a set of the early sliding cylinders, for 1976, if anyone needs some. One old non-leaker and one new non-leaker. And brake shoes. I switched to the 78 style brakes. A puzzle for the next owner.

If I read the bigger picture right you have two old cylinders, one of which was leaking, and two newer cylinders, one of which is leaking. So, hoping that moisture and storage hasn't damaged the older non-leaker, and that you still have it like a good hoarder should, you have an old non-leaker and a newer non-leaker. Esthetically displeasing but should get you on the road while you work on the mismatched leakers.

I didn't see a direct answer to this but I'd just replace it. It's bolted in. Somebody should have one for cheap and they're not that heavy. Just an odd part to have shipped.