Zed Head

I'd check the valve cover closely. There's no oil passage on that side and the engine tilts the other way. Actually the illustration is poor but I think that only oil passage is on the filter side, for the cam towers or spray bar, and sometimes one up front. But none back there on that side.

I do remember having to put the two front bolts in in a certain order and angle of rod. Leave everything loose and wiggle things around until you get both front ones inserted. So, not a drop-in but much easier than wheels hanging.

Today. Pretty good money for an auto. $25,750.

The tachometer is connected to the the coil on the same circuit as Pin 1. The circuit branches on the way from the coil to the ignition module, the tachometer and the ECU. I think the split points are by the ignition module. Find the blue wire at the ignition module and track it back and you might find the branch points. Nissan used crude crimp junctions to make the branches. Nasty looking but normal. Maybe the Pin 1 circuit got pulled loose or the wire got cut.

The Fuel Injection Manual was written for your car. It shows how to do the electrical testing directly at the ECU connection. You can test each injector circuit, confirm continuity and resistance and power supply. ECU's do fail. Nissan's final instruction after testing everything is "replace ECU".

Have yo verified that you have power at the injector plugs? The EFI system harness gets its power through its own wire which also has a fusible link in it. Check for voltage at the plugs with the key on.

I had the same issue the first time. The second time I learned that with the suspension loaded they go right in. Wheel's hanging = almost impossible, wheels up = easy. You can reach the nut from the side of the car, underneath, even a lowered one, or from the engine bay, with the car on the ground.

Those projects are never getting done now...

I was wrong, it sold. SOLD FOR $70,500 ON 3/15/21 Probably somebody who saw it in person at the SEMA show. Still doesn't seem practical, some people were asking if it could be a DD. One bad speed bump and the exhaust is crushed. Who knows. The car was shown at the 2017 SEMA Show in Las Vegas, Nevada

The street racer is up today. RB26DETT with lots of extras. Already at $39,500, now 40... https://bringatrailer.com/listing/1972-datsun-240z-168/

Compression rod, but T/C rod is the common name. It sees tension or compression when the wheel is pushed back or pulled forward (edit - actually vice-versa). The video does fit that part as a possibility since it happens when the wheel hits the curb. They're known to break also. The nut in the back could be loose. p.s. you can see it and reach down and grab it, from the engine bay. It's right there.

So close!

It looks like it's just a run-of-the-mill relay. Three wires. Any common relay could be wired in. You can take the factory relays apart also. You might find that it can be cleaned up and function restored.

77 2+2 4 speed R200. Odd combo. Looks in decent shape. https://bringatrailer.com/listing/1977-datsun-280z-22-8/

https://www.atlanticz.ca/zclub/techtips/fuel/gastank/index.htm

An open valve might cause intake popping. The valve lash gets tighter also as the engine warms up. So it seems possible that a valve or two might not seat fully as the engine warms up. Just for clarity, these engines often get what people call "front-fire" or intake system popping. Backfire usually means popping out of the exhaust pipe. I'm guessing the noise is from the intake manifolds/carbs?

It won't affect it at all. But it's not looking like you need to move it. And the engine should still run well even with cam timing off. Have you set ignition timing? Can't really tell which notch on your damper the pointer is pointing at but, actually, everything looks pretty good. Backfiring could be lean mixture, or incorrect ignition timing, or flattened cam lobe. First thing I'd do is get a timing light and set timing to 10 degrees. Also, make sure that your firing order is correct on the distributor cap, since you've been working there.

Check the exhaust manifold temperature, one end is probably cold. Front or back.

The sound. Compare.

Do you have a picture of the timing mark on the damper? Like site said your timing would have to be way way off to have the notch over there, if you're on TDC.

I don't hear all six, but not bad. Lots of work ahead but at least you know it will probably move once you fix all of the other stuff.

Here's another video that might be interesting. Shows the combined points and condenser. https://www.classiccarrestorationclub.com/video/set-point-gap-dwell-013696/#

Hard to see through the rust and grime but as you say the 240Z condenser is outside the cap, and connected to the points system. Older US cars used to have them inside. Found a 240Z video that looks promising.

Another silver car, a one owner 77 5 speed. I'm going to guess reserve not met. Too many silver cars lately. https://bringatrailer.com/listing/1977-datsun-280z-52/