Zed Head

Did you mean switch, not module? Can't remember the details of the first problem that caused you to replace the part, whatever it is. Maybe write a short history of problems up to now. There's not much to the system that sends power to the starter solenoid.

SU's use a piston to control air flow. Might be that your pistons are stuck, among other possibilities. Not sure how to fix that.

Is there a typo? Why would a shorted O2 sensor affect a cam sensor? And why would anything "burn up"? No fuses? Just wondering.

Might be the ignition switch. Fairly common for the pins in the switch to get loose and lose connection. Or for the mechanicals to wear and the key does not turn the electrical portion of the switch far enough. If you can get to the switch and take it apart you can get the definitive answer. Turn the electrical portion with a screwdriver and see if you get power then.

The Z switch is just a two wire switch. Power on one side and ground on the other. I converted mine in to a "headlights still on" warning buzzer.

Your battery is probably low on charge.

The switch above the brake pedal is known to break. Two wires and a spring loaded button. https://zcardepot.com/products/brake-light-switch?_pos=1&_sid=e77632f40&_ss=r

Hmmm.... https://www.classiczcars.com/forums/topic/63698-covid-19/?page=70#comment-623001

Oil is fascinating stuff. It's taken millions of years to be created but we're using it on the decades scale. You can find a ton of articles out there trying to explain the use of ethanol. But oil is just too easy. https://www.ag.ndsu.edu/energy/biofuels/energy-briefs/history-of-ethanol-production-and-policy

Ethanol's original reason for being used in automobiles was to reduce dependence on petrochemicals. In part to avoid the situation that exists with Russia and Saudi Arabia. Once the industry is created it tends to become self-sustaining.

Thanks for the response. But, Bad Dog is really just like us. I don't think that he has inside knowledge. Many people look at things like that and decide "what else could it be?" and let their imaginations create something. ennisdavis actually had a good point about the robustness of the piece. Plus the piece is not designed properly for a downward load. It would probably bend more easily than the tiedown loops on the front and back. I look at it and think that it might be for fixturing during manufacturing. But I don't know, it's just seems like a reasonable guess. Anyway, if somebody has another source that would be cool. Maybe Honsowetz or Monroe or Humble mention it one of their books. Maybe @katsknows, although it looks like they only showed up on 280Z's. Here's the part being discussed. And on a more whole car.

That is interesting. I've not heard that myself. Can you describe the source? No offense, but without it, it's just two opinions. We're all just people with Z's on the internet. p.s. I've read that the loops on the front and back are for tiedowns. But I haven't read that about those metal pieces on the body stiffeners.

I browsed through a bunch of carpartsmanual pages and only found one drawing of the thermostat housing, in EFI Control. It does show a side port but I can't find a switch defined for the hole anywhere on the other pages. The carparts site is setup in a way that you have to know something's purpose before you know where to find it on the site. http://www.carpartsmanual.com/datsun/Z-1969-1978/engine-280z/e-f-i/control

Most likely explanation might be that it has been in an accident in the past. Maybe hit a log while it was on the beach collecting salt.

They can last a long time before they are unusable. There are threads on the forum from people who took theirs apart and found signs of destruction even though the transmission still worked properly. Strips of bearing cage/retainer, loose ball bearings in the bottom of the transmission. Still worked.

I think that most of today's manual transmission cars use the clutch safety switch, not a neutral switch. So your first idea would match what a modern car uses. I have a 2003 vehicle and it has a clutch switch. If I start it thinking I'm in neutral but I'm not and let the clutch pedal up it will still jump forward (of course), just like a car without a switch. Does the second set of points really use the kickdown switch to change which set of points is used? I thought it was a temperature switch. Either way, all that matters is to be sure that the points have power under all driving conditions. Connecting the wires together should work, but there are probably other ways, like just bypassing the switch itself, or shorting it internally.

Please don't let this turn in to a grievance thread. I get a sick feeling in my gut when people start complaining about politics on a car forum. Complaining about fuel quality because your unnecessary hobby car doesn't run the way that you want it to is like a train hobbyist complaining because he can't find coal for his antique engine. Things change. The history of the internal combustion engine is a model for the development of electric cars. Set standards, build stations, develop a supply system. It took time, and there were problems along the way. Expecting private enterprise to do that is unrealistic. Besides that, private enterprise will do what is best for itself, not the greater society. Dump their waste products in the rivers, bury them in the ground, whatever makes the most profit. Think of the bigger picture. If you want your old hobby car engine to run well on today's fuels, modernize the engine.

I wonder if there was some combustion chamber valve unshrouding done. Those pressures just seem really low like the combustion chamber is enlarged. You could use one of those calculators, like OZDat, and back track to combustion chamber volume. Then recalculate to what CR would be with flat-tops. You might find that you'll still have low CR. Or maybe you just have really bad rings. Seems like if you had bad rings you'd have some variation across the six. One or two cylinders much worse than others. Good luck.

Couldn't tell where the blade was. Anyway, a picture through that hole would show what the bimetallic strip pushes when it bends. All interesting stuff, digging in to the guts of the parts. But, with no power through the circuit, he'll have to wait for engine coolant to heat things up and cause the strip to bend.

Not clear why buying a different AAR without actually testing the power circuit seems like a good idea. I remember having my fuel pump powered from a separate circuit, for testing, and the idle speed took forever to drop to normal. Because the AAR heater had no power. It bends (the two different metals expand at different rates) and pushes on the edge of the metal plate, causing it to rotate. You can see that the bimetallic strip is not in line with the passage, it's next to it. If you dropped your orange screwdriver down to the next hole you'd see what gets pushed when the strip bends. I can't remember exactly how the parts fit together.

Have you tested these? I'd guess yes, since you're a Z aficionado, but confirmation is always good. That middle one is pretty shiny. Nice arrangement.

The meter or light would be used on the connection at the end of the harness. With the engine running. You can connect 12 volts (maybe even just 9, not sure) to the two pins on the AAR and wait and see if it closes. It doesn't have to close all the way. The amount that it moves will determine how much idle speed change you get.

You might have saved some money then. Do you have a meter or test light and know how to use them? It's pretty hard to get by on a 280Z or even a 240Z without that ability. The parts cannon is not a precise weapon.

Actually, per Cliff/siteunseen's response, the answer is "undefined". "Distributor alignment" doesn't mean much. But Cliff's answer has what you need.

What ratio? "Original" could mean many different ratios.