Zed Head

Look at at 30, 31 and 32 here - http://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/transmission-case/4-speed/from-sep-71

What happens if you connect the two wires? If it's a switch, then something should light up or buzz or something. I seem to recall also, that the "top gear" vacuum advance function was actually introduced before EFI. It's an emissions function and 73 was one of the first emissions vehicles. Might be a top gear switch.

He apparently, according to the words on the page, installed the 123 directly after having the engine apart. Must have had the oil pan off to check the rod bearings, and must have changed the water pump. So a fair bit of disassembly. Put it all back together, installed the 123, and cranked it up. Then smelled smoke on the drive and the engine was struggling to run. That sounds like overheating to me. Breaking the rings on a single cylinder will cause the engine to run rougher but it will just keep going easily on 5 cylinders. Might burn some oil but it will probably run okay, on 5 cylinders. Seems like he did a repair and an "upgrade" at the same time, had a problem and blamed the upgrade. But it might have been the repair. Overheating can lead to detonation. I wonder if he got it fixed and realized the true cause. Who knows.

Rill Cosby hasn't been back since December of 2019. I did notice another odd thing in his first post.

The parts look like 280Z parts if you compare to Rockauto pictures. If moozieman is 100% sure that it's the distributor then there's only one thing to do. Remove the distributor and check it out. The overall description doesn't really make sense anyway. Why would the rotor grinding on the cap cause the engine to die? The engine would happily just grind that cap and rotor in to dust.

What do you know about the engine? Why was it parked? You might get the engine spinning with starting fluid before spending on new carbs. Like site says though, clean things up first. Check your air passages, the intake manifold, etc. Squirt oil in the cylinders and let it soak for a while. Take the valve cover off and check the cam shaft. Spin the engine by hand and with the starter and no plugs to make sure it doesn't have a rod about to poke through the block. Basically, try to be sure the engine is worth spending money on. Then start spending.

I thought it was a heat shield.

Put your finger on the top of the shaft and see how much play there is. Wiggle it and see if it moves far enough to touch anything. Or just take the distributor out and see if there are any obvious problems. While it's out see if the drive quill (down in the hole) has problems. Your problem doesn't sound complicated but you're going have to go farther to solve it. It's an uncommon issue, nobody out here will have the easy fix. Time to take things apart. Removing the distributor is super easy. One screw, and disconnect the red and green wires, and it pulls right out. It only goes in one way, so you can't really mess things up. That distributor is so rusty inside that it's almost guaranteed that your vacuum advance doesn't work anyway.

Don't the push button style work by only partial thread engagement? Only at the button? Will it survive the stress of the puller? Guess you'll find out...

Doesn't really sound like a distributor problem.

Have you started it? What does it do?

That's a 280Z distributor not 280ZX. Looks like the lock-down screw ins in place and tight. Were both spring clips properly in their slots when you removed the cap? They can be difficult to get in to position. I always have to use two screwdrivers, one to locate and one to apply pressure until it snaps in to place. Can't get my fingers down there. Did you check the cap for looseness when you wee removing it? This was mentioned earlier as a possibility. The cap should be rock solid on the distributor body. Pressing on it should have no affect at all.

Post #3/4 of the way down Page 3? No good?

Does it sit there stable or move up and down with driving? I think 195 is recommended for your part of the world. "Cold". http://www.carpartsmanual.com/datsun/Z-1969-1978/engine-280z/cylinder-head/41

Still waiting for that picture...

The cap should be very solidly locked to the distributor body. No wiggle at all. If you can press on the cap and see it move independently of the distributor body, that's a problem. Take a measurement across the bottom of the cap. Maybe somebody out here can compare to what they have. Kind of sounds like you have the wrong cap.

I don't even know who you are mbz. And I reserve the right to reply to other Classiczcars.com member's posts. The topic turned to the AM in AMsoil. The marketing plan. Not whatever your original question was. I think that Tupperware has a similar arrangement. Edit - forgot to say. You can use the Ignore feature of the forum, and never see my posts, as long as you are logged in. I use it on a couple of members and it works well. Just hover your mouse over my screen name and the option will show. "Ignore User".

Wiggle the cap.

I've seen the name Amsoil for years and seen comments about their "pyramid" marketing scheme but just now made the mental connection to Amway. You don't make money until you get other people to start selling for you. In the end everyone is an Amway salesperson. Then... the rapture. No offense...

That's odd. What does it mean? With ballast the coil would take longer to "charge" and current flow (voltage) would be lower, but last longer. I wonder how you could modify the tach to offset that. More loops on the back of the tach to make it more responsive to the shorter time? Interesting finding.

If I recall right there are different size distributor caps out there. I think that the ZX cap might be a hair smaller. If you put your 280Z cap on a ZX distributor it might be loose. Or if you went to the auto parts store and asked for a 78 280Z cap, but you have a ZX distributor. A possibility, I think.

$18,000 sold

37 minutes. $13,250. https://bringatrailer.com/listing/1973-datsun-240z-106/?utm_source=transactionalemail&utm_medium=email&utm_campaign=bat_model_notification

I saw it. But they are the wrong photos. You need this one without the rotor. Closeup. to see if the shaft has play.