NewZed

Here's a fairly easy and cheap ignitor (transistor) swap - http://www.zcar.com/forum/10-70-83-tech-discussion-forum/285085-hei-ignition-control-module-swap-info-turbos-only.html The 83 turbo doesn't have "pickups", it has an optical sensor with wave-forming circuit that creates a square wave for the ECU to use, to trigger the ignitor. The system in the distributor is generally called a CAS, for crank angle sensor. Could be your problem. Turbo ZX ignition problems seem to be hard to diagnose.

The GM rubber mounts will fail catastrophically in tension. ES addressed that problem. The tension that they see in this application is inertia from big bumps, and deceleration while in gear pulling the diff nose down. Could wear out the urethane, but the metal interlock controls the damage, In theory. Seems pretty smart. http://energysuspension.com/products/Transmission-Mounts.html

If you're not going to learn the 280ZXT engine then the small block is the way to go, since you're familiar with it. Two days ago you were trying to find someone to work on your engine. Apparently you haven't found anyone? Totally different driving experiences between the two, I would guess. Might be easier to just trade for a Camaro.

I could be seeing it wrong in the video. The lips should point in toward the oil. Posted a picture from the manual. "Stuck" doesn't tell how far the slip yoke went in, if at all.

It's very normal. The rubber seals around the outside of the driveshaft sleeve yoke (the part that you stick in there, you're calling it a collar, also called a slip yoke). The sleeve yoke might be sticking because you have the seal (the new rubber) in backward.

You never answered TimO's question in #4. There are two parts - the locking part and the electrical switch part. Screws hold them together. Take the component off of the steering column, take screws out that hold the two pieces together, and use a screwdriver to turn the electrical switch. That will tell you if you need a new electrical switch. Leon may have been referring to the weak solenoid power problem. If you had mentioned a click along with the no power, that would be a path to follow. He can add on. If you want to be as effective and time-efficient as possible, measure voltage at the solenoid wire while someone turns the switch. No work required, but you'll know more than you do now. Sounds like you haven't really done much except turn the key and listen to what your brother-in-law said. This is an easy problem. Do you have a meter? Just trying to help you make some progress. If you want to spend $100+ on a new switch, that's your choice too.

Bend the bar. It will make sense after you take the switch apart.

You can bend some extra twist into the flat bar that connects the lock cylinder with the electrical switch, if the problem is that you're not getting power to the starter solenoid when you try to start the engine. Can't really tell what you mean.

They probably are expensive because not many people buy them. That means there aren't many people who can tell you anything about them. There are some tricks to fix them. What's wrong with yours?

By "Optical Dizzy" do you mean the CAS in a 280ZX turbo distributor? How long is "a while" and how long is "a bit later"? Is there heat involved? Your details are vague.

So the P90 is not just the P79 design with no-liner square exhaust ports? I thought the combustion chambers were the same size. Assumed that the chamber shapes were the same. The valve sizes appear to be the same size also. If they're the same, then the comments apply to the factory stock NA P79 head engines with flat-top pistons. Deck height is a block measurement and relates to how close the pistons get to the head, so it sounds like he's saying the "quench" is wrong for a P90 with flat-tops. Seems like it would then be wrong for the P79 too.

Electrical noise, from anywhere, was the point. The starter was just one example.

That should tell you something.

One common quick test of a fuel pump is to pinch the return line and see if pressure rises.

Measure voltage, engine stopped and engine running. Or look at the voltmeter in the dash, same scenario. Look at the charge light in the voltmeter. Does it light when the key is On, then turn off when the engine starts? Those are some basic diagnostic tools for a charging problem.

Page 150 of Cramer and Hoffman's Performance Fuel Injection Systems book describes a situation where electrical noise from the starter caused crankshaft position sensor signal loss.

Pretty sure those numbers are in the Front Suspension chapter. I just made mine really tight. The nut clamps down on two washers and a metal sleeve, on a shoulder of the rod, so it's all metal on metal. Use Loctite.

The EFI harness in the early 280Z's is essentially completely separate from the the rest of the body harness. It even has its own fusible link. You can unplug it without chopping any wires, leaving all of the other car functions intact. I have one from a 78 in my garage, no cut wires. Search for threads dealing with switching to carbs. You won't really be modifying anything, just adding a few more loads. Some relays, a power supply wire, and grounds, are all you need to focus on. If you find yourself getting ready to chop a wire, you're probably making a mistake. Some of the guys on classiczcars.com have put together some really nice full color wiring diagrams in .pdf format that would be handy for you. Much easier to deal with than the photocopied FSM diagrams, or the paper FSM. Don't think in terms of "chopping". Chopping is bad.

Spark strength is a possibility. If you're seeing a spark from the coil then you're getting a trigger and the ignition transistors are breaking the circuit. Weak spark could be from dwell time on the ignition set too low. You should really post your MS settings so one of the Megasquirt guys can get you closer. You're making progress but could take a wrong turn at any moment. If you can't save a file just do a print screen to an image editor or use the Snip tool in Windows accessories to get a screen shot. Your hardware seems to be working, it's your software that needs help.

The distributor rotor spins inside the cap. The spark jumps to the closest electrode. You should always have spark at the spark plugs. Timing is when it happens. Connect the timing light to a plug wire and see what happens. Injectors don't get spark. They get grounded so that current can flow, opening them so that fuel can squirt. To be ignited by the spark, if it happens at the right time. Some people don't want to bother with terminology but the words are the only way to describe what's happening, or supposed to be happening.

Why are talking about spark to the injectors, and how do you know you have "spark" from the coil to the distributor? Spark travels from the coil to the distributor cap to an individual electrode and down the wire to a spark plug. One at a time. There will be no spark from the coil unless it has a place to go. It has to end up somewhere. It has nothing to do with timing, spark doesn't care what time it is.

That's the power wire to the 1978 EFI system, with the fusible link intact. There would be a red wire with the opposing white connection on it from your harness, to plug in to, with the original EFI harness. By the way, you didn't mention anything at all about a different engine in the car, so I just guessed based on your other statements.

Here's another, same idea. 1975. You must be looking at early Z R180 pictures. Attached a 1973 picture for ref.

Show some pictures. A variety of parts flipped, turned and spun, and off by 1.5 - 2" is hard to visualize. And you didn't say if you have an early 260Z or later. Small bumper or big. Also, I've noticed that Nissan used "transverse link" to describe several things. If you mean the curved link between the uprights, that shouldn't affect where the nose of the diff ends up. It looks like there are two TTT bars, one R180 and an R200. Maybe you have the wrong bar. https://technotoytuning.com/nissan/280z/mustache-bar-datsun-240z-260z-280z

I had the clunk for a while and decided that the actual noise is not from the nose going up but when it drops back down. Lift-drop-clunk. A new stock diff mount along with the snubber might do the trick. The ES mount is convenient though, since it will let the diff hang by itself and is nice if you do any work on the suspension. You can remove the cross member without worrying about the diff. U-joints can cause noise with just a little wear. They're hard to diagnose without prying them around with a lever and examining with a good eye under good light.