Zed Head

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.

Need the same picture, but from yours.

They advance the timing based on temperature, just like the 280Z distributors do, using the ignition module instead of the two pickup coils in the distributor. It's shown on page EL-26 of the 1983 FSM. I'd post a picture but there's something wrong with the forum. Out of storage space, I believe. "Image could not be saved. Please contact us for assistance." "Upload failed". @Mike

I actually did notice that the one you took out seemed backward, in the pictures, from the one you out in. But, I trusted your experience.

The magnet is circular. It tends to break.

The kind of look like they go under the dash, inside the car. Don't know.

@Dave WM needs another engine. It's already on a Harbor Freight engine stand.

This guy needs one of these. He'd probably take the whole spring piece.