Zed Head

A timing light should give you an idea of how the timing changes with RPM and throttle position.

This sounds more like a carburetor problem. Flooring the accelerator removes vacuum advance from the equation. A tight spring in the vacuum advance canister would reduce timing advance. Low RPM would also reduce timing advance. I don't know much about the SU carburetors but it sounds like a jetting or needle placement or piston problem. Maybe one of the carb guys has some ideas. Edit - the behavior is what engines do when the fuel-air mixture is lean.

Remove the striker from the car body and manually insert it in to the door latch. That will give you a clue if it's an adjustment problem or a sticky latch. If it's a sticky latch you might try removing it and giving it a good hosing with carb cleaner then relubricating.

https://www.classiczcars.com/files/

The 280ZX alternator is internally regulated. I can't remember from your previous posts how you modified your wiring to run the ZCD internally regulated alternator. You need to decide on external regulation or internal regulation, and get the wiring correct for that system. I think that it's all been covered in past posts. Both methods work the same way. The main problem with external regulation is finding high quality external regulators.

Good luck getting an exchange or refund from ZCD. You can get a 60 amp 280ZX alternator from almost any auto parts store and go back to the "T" plug. It should bolt right up and work just fine.

The ZCD "upgrade" alternator is a more modern alternator without a T plug. It requires wiring a new plug on to get it to work. It's in an old thread.

That is better. It looks correct. Seems like your alternator voltage is not being regulated. The engine starts and the alternator pumps out too much voltage and current. the high idle makes it worse. So, the problem is either in the alternator itself or the wiring to the S terminal at the plug. I think that this has been discussed before. The wiring at the plug on the ZCD alternator is still not right. Maybe you could dig up those old posts about the ZCD alternator wiring.

Hard to see what's connected to what here. Not a great video, most of it points at nothing. No offense. Your problem is probably here though.

The starter draws huge current. It should draw through the main positive cable. But it also needs a good ground. Are you sure that the "fusible link" is on the positive side? Or do you have it connected to the wrong terminal at the starter? I'll see if I can see it in your video. Anyway, it sounds like your starter circuit is the problem.

When, exactly, does it "burn up"? I remember your past threads. Does it get hot when you connect the battery, or when you turn the key on, or when you turn the key to Start, or when the engine is running? I would narrow it down to one of those four, it will tell you a lot.

Isn't that what the condenser (capacitor) in the distributor is for? The ballast is to keep the coil from burning up. It's the thermomechanical version of "current-limiting" ignition modules. Kettering.

This Beverly Hills car actually looks kind of interesting. Beat up, but hard to tell how bad. https://www.beverlyhillscarclub.com/1971-datsun-240z-c-13399.htm

I think is where BaT RNM's end up. https://www.hemmings.com/classifieds/cars-for-sale/datsun

This was on BaT a short while ago. Made it to $27,250. Looks like the reserve was $45,000. Red... The Hemmings article uses the BaT verbiage as the seller's description. I wonder if BaT allows that. Seems like free work. It's not fantastic but still has that tone to it. https://www.hemmings.com/stories/2022/01/14/after-some-minor-updates-and-refurbishing-this-1971-datsun-240z-is-primed-for-long-countryside-jaunts https://bringatrailer.com/listing/1971-datsun-240z-201/

I've had a brand new slave cylinder leak. Sometimes you'll find machining grit inside if you take them apart, even brand new. Quality control on aftermarket parts is just poor. Take it back and see if you can exchange for a different brand, then take it apart at home and clean it up inside before installing. I think that EuroDat has seen similar if you want to search for past posts about it. @EuroDat

I'm saying just buy a complete used R200 with 3.9 gears. Typically found in the 1980 -1983 280ZX 5 speed cars. They're out there. You could probably buy a complete junked 280ZX for less than the cost of new gears if you find them. Actually, I doubt that you'll be able to find gears for sale. A used R200 is probably your only option.

It would be easier and more effective probably to just buy a 3.9 R200 with good gears. I don't think I have ever seen anyone talk about worn gears on their R200. But here are the part numbers if you want to try to track new gears down. http://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/differential-gear/r200/13

280Z https://bringatrailer.com/listing/1975-datsun-280z-34/

Too bad the 280Z's don't generate the same excitement. Seems like the 240Z's are becoming collector things, like Pokemon cards. The value is in the scarcity. The value could disappear overnight once a new thing comes along. No offense intended, just a thought. https://cardcollector.co.uk/collecting-pokemon-cards/

I'm not trying to cause trouble. Just talking about an interesting car. Your build thread is too long to search through to find the explanation. It really stands out in the pictures.

This is for AC hoses? Looks like a great job on the car. Good luck.

Isn't it really a resto mod? Resto perfecto maybe. Parts have been replaced with better parts, but they are not original, therefore not resto. Just pretending I'm a car show judge. Anybody know what this thing is...

Looks like the silver foil from the top of a gallon jug of oil. ? If it is a bearing failing you will hear it eventually. Measuring cylinder pressures, examining cam lobes, checking timing chain wear...those are the typical things you'd do to determine engine wear. 136,000 miles is not a huge number for these engines.

What engine? How many miles? What do you know about it? Can you post a picture of the copper flakes? Might just be from the washer on the drain plug.