Zed Head

Not really clear what you're talking about when you say lock or lock point. Sounds like you're saying that the snap ring grooves of the u-joint don't match the inner surface of the yoke. so the u-joint is not centered properly. It would help your argument a lot if you had a picture of you taking a measurement. Not clear where you're getting your information from. John from Lugoff probably would have noticed a 1/10th of an inch gap on each side (huge), but maybe not. http://www.northerndrivetrain.com/product/NEA-1-0430.html

Thanks for doing this. Searchability by word would be great. I have not downloaded it but most of what is available out there is either just the full FSM as one giant file or a collection of chapters with bookmarks. Are you using some sort of character recognition to convert pdf images to actual searchable text files?

https://www.classiczcars.com/forums/topic/65183-78-22-driveshaft-u-joints/

It's not the alternator it's the wiring from the external VR in 1976. If you follow the two main wiring suggestions on the internet, one disables the brake check light, the other causes the relay to be on al the time, draining the battery. The wiring diagrams don't work for 1976. The Frontier alternator is just like a ZX alternator except for the type of electrical connections.

I think we owe kudos to Z Car Depot for showing that the Frontier alternator fits, has the proper pulley, and has higher amperage. Too bad the instructions he provided are so poor, he opened the door to your discovery. The wiring is pretty straightforward, once the Sense and Lamp wires are understood. More complicated for the 260Z of course, with the fuel pump wire. And the 76 280Z has the brake check warning lamp to worry about. Most people go for more amps because of low amps at idle RPM, causing dim lights and slow wipers. Do you have an idea of if the Frontier unit provided higher idle amps with wipers, lights, heater, etc. on? Driving through a storm on a cold night.

Try opening up the idle speed screw and see how it starts. It's the one with the big washer head and spring underneath on the throttle body. If it starts and runs correctly right away but the idle is too high after it warms up then that would be an AAR problem. You've talked about how far open the AAR is but you haven't said that it closes quickly like it should, from the electrical heater inside. It might be that the AAR does not have electrical power and that you've adjusted the idle speed for a warm engine.

Good luck.

I had one break with the hard PU on the back and realized that the bushing on the back restricts the motion of the tip of the rod as the rod itself moves up and down with the control arm. This puts a big load on the stress riser at the bottom of the threads and causes the metal to fatigue and break. The rubber bushing is actually formed so that it allows a wide range of motion, up and down and sideways, of the rod but still controls fore and aft motion.

Not clear what this means but if the tachometer needle does not seem to match engine RPM correctly that is a sign of an ignition module problem. If banging on the ECU clears up the rough running, that's an ECU problem.

Kind of sounds like the bad ECU problem, or bad ignition module. Did it smell like raw fuel?

Same thing?

Need details. Without the AAR you would need to hold the throttle pedal down with your foot to keep RPM up.

1978 had the first "adaptive dwell" system for the Z's, I think. At least they trusted it enough to run enough current to open the plug gaps. The 1978 spec should work for the Ignitor II. Some people like to run the projected tip plugs but I'm not sure it makes a difference. Not sure why Nissan changed, maybe due to detonation issues with the leaner EFI systems. Just a guess.

I'd get the plugs for the engine - a 78 280Z.

Once you get past a certain point you kind of have to use your own tricks. The roll pin can be hard to get out, to disassemble the shaft. Check your timing advance movement with a timing light and you'll get a good feel if it's responding quickly and correctly. Hook up the light, rev the engine, watch what happens. Disconnect vacuum advance and do it again. Hook up vacuum advance to full vacuum at idle (you have to find a port), you should get full vacuum advance immediately.

The Ignitor II is an adaptive dwell system, AKA current-limiting. If you use it with the low resistance coil they suggested, the FlameThrower II (primary resistance 0.6 ohms), you should be able to use the larger plug gap.

The breaker plate (the assembly of parts with the screw and the ball bearings) can be disassembled. There's a snap ring in a groove that lets it all come apart. Then you can shine up the ball bearings and the surfaces they roll on and slide against. The black piece with the bulbous protrusions needs to be smooth inside so the ball bearings can slide. Several people have also found that the vacuum diaphragm was shot on their old distributors. If you're not going for reproduction you might be better off getting a newer distributor and making it work. Keep that old one as a piece of garage art. It has some unique features, like the external spring on the vacuum advance module. You didn't mention the centrifugal advance pieces either. They need to move smoothly also. They're under the breaker plate, weights and springs.

Looks like the very early distributors didn't have the second set of ball bearings. 1972

I think that it is Nissan original, I've seen it described. Maybe even in the FSM. Looked at the 1970 FSM and these drawings/pictures came up.

Are you saying that he had the wrong ones installed? You said that they were new in the first post and that it's an early model. That would be short in short. How can they be wrong? Not really clear what's going on.

The condenser by the coil is for radio noise. Leave it there. https://cdn.shopify.com/s/files/1/0247/6913/4628/files/1761.pdf

The color wiring diagram doesn't make things clearer. Two blues. Oh well. Edit - actually, compared to your picture it does make more sense. The FSM seems to be off.

I have vague memories of the wiring diagram colors not matching the car, in past threads. I think it ended up as just one of those things that is, reason unknown. The wait for voltage spikes is on now...

I'd be willing to trust 77Z's vision. W/R = White with red stripe, etc. The only secret is that L = blue.