Zed Head

They worked! Yay. The melting (fusing) process can be incomplete. Even a single strand of wire remaining will show continuity so that not a good sign of viability for future use. Check the fusible link for the EFI system also. It's connected to the positive post at the battery. 78 used two greens side-by-side, exposed. Also make sure that you didn't get the EFI wires switched. They used the same type of connectors for negative and positive. (Genius!). Hopefully you didn't fry the ECU. All of the things you touched have the possibility of reversed positive and ground. Even at the starter. These old Z's are well known for using red and black indiscriminately on the big cables, for some odd reason.

Your points are all good ones. The pulling of air through the seal would depend on the balance between the rate of pull (the spring force of the spring behind the piston) and the viscosity and availability of the fluid through the tube from the reservoir. And the tightness of the seal on the piston. So, lots of other variables besides luck. But it's something to be aware of. I think that the same things apply to vacuum versus pressure for brakes. If you pump your vacuum chamber way down to close to true vacuum you're more likely to suck air past the seal I'd guess. And, applying all of this to the "corner" theory, you can see that a slow fluid flow to avoid sucking air could lead to leaving corner bubbles behind. In sum, considering all, for me, a shovel handle against the seat back remains my preferred method.

Oops. I had the wrong year. Like yarb said, the cars with external regulators used a single prong oil pressure sensor. Round. You can put a flat terminal on that wire and just use the sensor terminal on yours. The other terminal is a switch. Don't know on the other wire.

The picture reminds me of another way to bleed cylinders - work the system in reverse, from the end. I did that on the clutch slave cylinder. You can open the bleed screw and push the piston backward with finger pressure. That drives the fluid out of the bleed hole, then when you close the bleed screw, it pulls new fluid in from the reservoir. You can also unbolt the cylinder so that it has the screw hole oriented upward. This is in the same vein as pressure versus vacuum versus mechanical.

This is the main problem with bleeding brakes. cgsheen1's pictures show that it could still be a concern. The "calipers on the wrong side" issue is an example of a large "corner" in the flow path of the fluid. The rear wheel cylinder picture shows a small corner. Really you're talking about dead zones that don't get swept by the fluid and are higher than the flow path of the fluid as it moves to the bleed port. That's where the bubbles go. Be the bubble. If you had cgsheen1"s cylinders you might want to lift the side your bleeding waaay up in the air before starting.

They are. But that's probably a very early 240Z shaft used on the cars with the forward-set differentials. Those used a shorter propeller shaft. People use them with the 71C transmission conversion, but they're too short for a stock 280Z coupe with a 71B transmission. Edit - actually I think that it would work but you'd lose that inch of engagement with the transmission. I think it might be closer to 1 1/2" if I recall right.

Maybe that's a reason people have problems bleeding Z brakes. You can imagine a pressure or vacuum bleeder that's moving fluid slowly leaving some air behind. I put speed bleeders on the back mainly because I wanted to purge the lines of old fluid easily but it might have helped me avoid some problems also. And, are those aftermarket cylinders? Might not be representative of Nissan. But, it does show angled drilling, maybe they just didn't get the angle right. Might be some guy on an assembly line eyeballing it. Thanks for the informative pictures.

I used a broken shovel handle and the seat back. It worked surprisingly well, several times. Make sure the vinyl of the seat can handle the handle end though. Don't want new cracks. Crack bleed screw, press brake pedal down with shovel handle, prop against seat back, close bleed screw, release handle. If the clear tube is set up with an upward curve you can see if any air bubbles came out.

I did not know this. I've seen the Z series in the wrecking yards but never noticed that it was tilted the other way. Wonder why they did that. They have two spark plugs per cylinder also and 8 terminals in the distributor cap. It's an odd engine. Apparently they were called NAP-Z here in the states. https://en.wikipedia.org/wiki/Nissan_Z_engine Note: All USDM gasoline Z20, Z22 and Z24 engines were known as NAPS-Z (NAPZ or NAPS-Z Nissan Anti-Pollution System), NAPZ motors had dual spark-plugs (two per cylinder) except the pre-82 versions and latest versions of the Z24i as fitted to the Pathfinder. All NAPZ engines sold in California reportedly had dual plug heads regardless of the year.

I can't think of a single time where I've read about the need for a higher capacity mechanical pump. Never read of any engine running lean because the mechanical pump couldn't keep the float bowls full. It might be a thing but I've never heard of it happening. A mechanical pump delivers a certain volume of fuel with each pump, and the pumps are tied to each engine revolution which also pumps about the same amount of air. Doesn't really help your quest but I don't think that you can make a direct comparison between the two types of pump. One's capacity increases automatically, the other's is constant.

Doesn't it depend on engine RPM? It's eccentric actuated.

You might not have the time but this guy went way deep in to all of the 5 speed details. https://forums.hybridz.org/topic/110792-high-rpm-shifting-dynamics/#comments

Just noticed the part about the bellhousing. I think that's an L series versus V6 issue. 2nd edit - Rockauto does not show a V6 for a Nissan pickup in those years. So they should both be L series bolt pattern. Edit - picked the wrong year before. Corrected. https://www.rockauto.com/en/catalog/nissan,1983,720+pickup https://www.rockauto.com/en/catalog/nissan,1985 Carry on...

Brake light on? Bleed screw on top?

This "long-tail" sounds great. I've not read of any of these 71B's being longer than a ZX 5 speed but I have read of the shorter truck 5 speeds. If you're unsure about length ask the guy to measure it end to end. You should have enough remains around to compare and be sure. I'll bet it's ZX length. Get some Redline MT90 in it and it will probably make you cry after all you've been through.

Nothing wrong with using it. Just be aware of the new risks. Contaminated electrodes and over-torquing. https://www.antiseize.com/PDFs/torque_specifications.pdf

Somebody is selling a pretty good replica. Might be the simplest route. https://www.rockauto.com/en/catalog/nissan,1973,240z,2.4l+l6,1209170,electrical,voltage+regulator,4884 https://www.rockauto.com/en/moreinfo.php?pk=45627&cc=1209170&pt=4884&jsn=378&jsn=378

I think the key is where the exit hole is inside the cylinder. Sometimes they drill at an angle and the position of the external threaded hole is misleading. Anybody have a spare cylinder they can take apart and examine?

I wonder what the story is behind ThreePedalCollective? The buyer back in 2019. Has not commented since last October. Bought quite a few cars in just a couple of years on BAT. Why sell the Z that was recently bought, with no reserve price set? Maybe ThreePedal decided this one was a poor investment and wanted to cash out. There would probably be some nervous Z owners out there if it had sold at less than $68,000. Investments are "supposed" to continuously increase in value. https://bringatrailer.com/member/threepedalcollective/

I don't think that one person makes a market. He went up $20,750 in one step and nobody even tried to add $100 to his perceived value. He picked up a number that felt "right" to him. But, if he has the money that's his prerogative.

The smoke could have just been vapors coming back from an open valve. You'll want to measure cylinder pressure before assuming you have a bad head gasket. The thrown rocker arm could happen because of a sticking valve, maybe a tight guide or valve seal. I'd just keep doing the small things to get it to run correctly and let the parts wear in and see where you end up. No need for panic.

What do you think about the replacement guts? Here's a better option. A Ford product with pins. And A, S, and L labels on them. https://www.rockauto.com/en/moreinfo.php?pk=45730&cc=1414673&pt=4884&jsn=587

The thought has crossed my mind about installing an electronic regulator inside the mechanical reg's box. Kind of like using a GM HEI module inside the box of an older ignition module. But if you want to keep what you have why not just drill the rivets or whatever is holding the parts and then replicate them after replating? Here's an example of an internal regular that might work inside the metal box. You'd need to find the pin diagram but I think that it should work. I picked a Nissan one but they're all the same general principle. https://www.rockauto.com/en/moreinfo.php?pk=45661&cc=1209350&pt=4884&jsn=384