Zed Head

You can change the vacuum advance canister. If it has a hole in it won't work. The other possibility is that the breaker plate is rusted stuck. That is common. Take a picture of whatever is under the distributor cap and post it. That is a harder problem to fix.

For 395 miles it looks in good shape. I wouldn't mess with it, since it's not broke. My uncalibrated eye gauge estimates that you still have 90% of the load bearing area left and no damage has been done. Why disturb it now.

Do you know how the cam lobe got chipped? How many miles or minutes have you put on it so far?

Is it a Haynes manual? Page 38 might still show something if you take a picture and post it. You could also follow the wire back and find the device that is being supplied current. Good to know that it has power though, keep the end insulated. Here's the site's FSM download area. https://www.classiczcars.com/files/category/11-240z/

That's not how the Factory Service Manual (FSM) displays their page numbers or figures. Not sure what you're looking at. Here's a couple from the FSM, showing a page number and a figure label.

Nissan liked to ground circuits to the block to complete them and pass current through whatever device they were operating, like the water temperature gauge. Do you have the FSM page number describing the water temp switch?

What color is it? Do you have a meter or test light? See if it has power. Automatic or manual transmission?

L Looks scary. Interesting experiment.

Or not on the base circle. Not sure which cylinder it is. p.s. just saw Jeff Berks reply... Question answered.

The hole position varies. They just drill in a straight line for some, then another straight line for the others, I think. Those lobes would be for the same cylinder. That looks like a very wide lobe separation angle if that chip is at the top of the lobe. I'd keep an ear on it, then an eye. http://datnissparts.com/new-oe-l6-camshaft-datsun-240z-260z-280z-l24-l26-l28-13001-e4182/

I don't see any holes in the three cam lobes you showed. The internally oiled cams have those to let the oil out. Why does he say "new cam" when it looks like you got a used one? That chip might work but it could also self-destruct rapidly. Looks like the chip is on the base circle though, where there should be almost no pressure. Only the anti-rattle springs pressing on it.

Ruined 71 with Bluetooth. https://bringatrailer.com/listing/1971-datsun-240z-178/

I use an awl, a wood screw, and vise-grips.

You can buy them at any auto parts store. No need to wait for delivery, just get them when you need them.

You're going to have to give a better description than "no click stop when I flick it with my finger". Make a video.

https://www.classiczcars.com/forums/topic/53344-drivers-side-door-locking-mechanism/?tab=comments#comment-623584

Since the thread quality isn't an indicator of the quality of the potential failure point your worry level should be the same. Your "new" used axle is just as likely to fail as your old used axle.

77 survivor. Going counter on the main picture, pointed right. Rebel. https://bringatrailer.com/listing/1977-datsun-280z-50/

Quiz him on what was good about it and what he would have changed if he still had it. Then go find one like that.

The diff mount seems to be sitting high. Look up in this hole and see if there is a nut on the threaded stud. Stole from Namerow.

Interesting plot showing vaccination versus virus.

Have you checked all of your grounds? Grounds are more important than most people think. Weird stuff can happen. Might be affecting the ECU operation. Random internet thing about ground loops... https://www.bapihvac.com/application_note/understanding-ground-loops-application-note/

Your test results don't seem to match what happens when the engine is running. Why focus on the AFM when the TVS has the biggest effect? I don't know that the AFM numbers are as critical on the ECCS systems since they have closed loop control. That's why they give a wide range in the specs. Can't offer much help. Your car seems to be haunted. Weirdness abounds. Lifting the distributor cap to fix a rough idle...unplugging the TVS makes it run right even though it tests correctly... Mystery.

Unplugging the TVS would tell the computer that the engine is not at idle. That is all. This causes certain things to happen. I'm not sure exactly what happens but the dramatic effect that you see suggests that your TVS is short-circuited or the wiring harness is, showing the engine at idle all the time when it is plugged in.