NewZed

Can you really see that rigid cross member as like the loose, floppy leaf spring of the Z? Seems a stretch. I missed johnc's comment, and repeated something similar in my post. Funny though, a lot of time is spent on making the unibody more rigid, with bracing and roll cages, but the mustache bar mounting points seem like obvious areas to mount a rigid cross-member to, for stiffening the body. In the bigger picture maybe the Arizona bar should be mounted rigidly (get rid of the urethane donuts on the ends), and the elastic dampers (urethane or rubber) should be placed at the diff, like in the ZX post mount. Stiffen the tail of the box, but keep a little bit of damping at the diff.

Didn't Nissan go essentially solid with the ZX system? Only rubber bushings damping slight movement, with rigid metal attachment points. The mustache bar system seems unbalanced from a design view - the front rubber-metal sandwich allows much less movement than the mustache bar. It gets overworked. Probably why they wrapped a belt over the top of the diff nose, to help out. Could also be that the mustache bar wasn't put there for the diff, or for ride quality, but to take loads off of the body mounting points. Maybe it started out solid and they went to the bushed spring as a fix for other problems. Overall, the Z diff mount system is an odd collection of parts.

Did he say why? Appearance, measurement, package...?

If you have short axles because the Honda diff is wider than the R200, you might be able to have an adapter made. Like the TR6 guys use. Note that one adapter is thicker than the other. One of those things you have to pay attention to. http://tr6.danielsonfamily.org/DiffGoodparts.htm

The reason they do all of this is because there are no simple axle swaps to get what you want. The viscous diffs use a different axle design internally than the early open and clutch LSD diffs. No swap and go options. Besides that, is the weak Honda diff the same width as the R200 you're installing? If not, the axles you want to use are probably too long. There are many things to consider and many threads describing how people have missed one or two of them.

The issue gets pulled out and beat up occasionally. There's a ton out there on how to get newer diffs working in older cars and it always leads to custom CV axles as the simplest path to success. People have cut and welded four bolt flanges on to 6 bolt stub axles so they could use the later model viscous diff. You could do the same. By the time you add up the design time, and pay the shop to do the precision work (proper welding, runout on the flange surface, issues with control arm interference [that 6 bolt flange is big and runs close to the arm on the Z cars], etc.), a custom CV axle looks like a better option. Just easier to cut and spline a shaft so that it can use the ends you want. Find a driveshaft shop that does CV's, give them a length to shoot for, and the two ends and they can probably get it done.

Look through what the kit has and determine what each bushing does. Then decide if you need the whole kit or just a few. Think about what affects the handling issues you're trying to change and focus on affecting those parts. You mentioned old shocks, but decided to buy a bushing kit. Several of the bushings sacrifice ride softness for handling precision. One man's increased responsiveness and road-feel is another man's harshness. If you're planning other changes like low profile tires, you might do those first, since they'll make the ride harsher too. Keep your variables separate so you know what's doing what. For the crowd - Is the polyurethane T/C rod bushing an issue with the ZX? I know it is with the Z's, maybe not with the ZX. Nissan moved the rod from mainly compression to tension, from Z to ZX. May have changed some other design aspects.

It's probably BSPT but I think that people have found an NPT that works. You might try the local Nissan dealer also. Or Courtesy Nissan, by phone. Some of those old odd parts are still available from the factory.

Considering that the hub and the inner mounting points have rubber between them and the arm, it's probably not a precision piece. Although the hub casting does have to fit between those ears and the two surfaces probably need to be parallel and of certain distance apart. If you can't get the hub housing in there you're kind of screwed anyway.

If the wheel is hanging on the strut when the car is in the air, the shock body will be pulled up against the top of the gland nut. So you'd have to check for shock body looseness with the car's weight on the springs. Just a thought. Clunk sources are hard to find. Maybe it's the nature of the Cusco diff.

Were it mine I would put the rear up on jackstands and shake the crap out of both wheels by hand, up, down and sideways, along with various other tests of hub or strut looseness. Check the gland nut. Loosen the top shaft nut and see if you can pull the shock body up and down inside the strut tube. Stuff like that. Seems like the stub axle would stay out if it came out, especially with all of that excess room. You might be focused on it because it's the only loose part you can find.

Does the car jerk when it clunks? Is it loud? Are you turning fast or turning slow? Are you accelerating rapidly while shifting or slowly? It never clunks unless you're shifting from 1st to 2nd? 3rd to 4th is silent? What are you going to look for when you take it apart? You checked "all the bolts under there" but did you check the right strut bolts and gland nut? Did you check the hub? The axles are the same length but the distance from the diff to the hub is different.

How did you check the functioning if there's no power to them?

The location of the fork in the hole, front to back, should correlate to the angle of the fork on the pivot ball which should be affected by the stack height of TO collar and pressure plate. You could measure from the front of the fork to the hole edge and see if anyone out here could do the same. You'll have to dink around with the rubber dust boot but it sounds like it might be removed already anyway.

Dirty battery cable connections are a possibility. On the no-crank issue, at least.

You might get lucky and pass with random adjustments and part replacements. Most people just end up totally lost. Even with carbs you have to know how many times you turned an adjustment screw. Numbers matter. Try the Fuel Injection Guidebook. 1980 version covers all years. You'll need a meter. Start with the coolant temperature sensor. http://www.xenons130.com/reference.html Good luck.

Seafoam is a can full of HC, with a little bit of rubbing alcohol added. And a ton of sales pitch, all in a neat looking can. You're in the common bind of trying to find a quick fix and ending up worse off with no easy way to get back to where you started, Keep track of where things started and what works. The details are important. Does "did that" mean putting the AFM back where it started or turning out the idle air screw, or both? Did you turn the screw out 1/2 turn or 5 turns? The EFI system requires some rigor and patience to get right but many people get it done.

C'mon, the shift key's not that much effort...

Put the tach back in. Take the condenser off of the coil. See what happens. A simple way to test the system at super-slow speed is to connect a wire to the coil negative, turn the key on, and tap the wire to ground. Every three taps should cause the injectors to click. Three sparks is one engine revolution. Might be a simple way to test variations. If you get injector clicks,maybe you're just firing bad gas. Too bad you're on a phone.

The coil negative circuit is an odd one. It connects the tach, the ECU, and the old ignition module. One wire, branched. I've had two cars, a 76 and a 78 that would not run without the tach installed, using the stock ignition modules. But, since I've installed a GM HEI module, the 76 will start and run without the circuit to the tach complete (removed the resistor and it started). But, the tachometer doesn't work right with the HEI module unless I have a capacitor on the coil negative terminal. Lots of cross-talk possibilities there. Did you disconnect the old ignition module under the dash? Maybe you didn't and you're getting enough anyway to break the coil circuit but not enough to trigger the ECU. You didn't say why you swapped harnesses. Year of car would be good too. Good luck.

Have you verified the ground circuit to the ECU connector for each injector? The 12 volts on each side is from the parallel power supply (someone on classciczcar explained that to me, Captain Obvious), but doesn't tell you that the ECU is controlling ground. Have you checked fuel pressure? Good that you've verified spark with starting fluid. Why did you change the harness? If the ECU is good, and it controls ground, and gets the Pin 1 signal, with fuel pressure the engine should run. Pin 1 is branched with the tach also. Does the tachometer work when it's on starting fluid? If it doesn't, you might not have a good Pin 1 signal. The ECU is sensitive to the signal quality.

Sorry, it's raining. And getting dark. There's no gap anyway, I checked later because it bothered me like yours bothers you. Mine were black. I seem to recall that one piece in the kit was from Ground Control but MSA might have sourced from various suppliers. They came with MSA part numbers, plastic wrapped, in a box. It was 2009. The kit was on sale.

Aren't there two sizes - 240Z and 280Z? Maybe you got 240Z. I don't know the brand of mine (MSA kit for a 280Z) but I had a gap on my 280Z. Smaller than yours though. I greased it up, installed it, torqued the bolts, and drove, and the gap closed. It's elastic and sees varying loads in use. It will adjust itself in use.

Put the AFM cog back where it was and turn out the idle air bypass screw instead. That's why it's there.

Must be more stringent in other counties. Too bad. You didn't say about the AFM adjustments. You also didn't distinguish between idle results and 2000 RPM results. What are the limits for the two tests, and what were the results for each one? Adjusting idle emissions is a completely different thing than adjusting throttle open emissions. Timing is advanced, if your vacuum advance hose is connected correctly and the distributor isn't screwed up, and the throttle position switch is different with the throttle open. You can get some pretty direct help if you add the details. Or you can go with the one time magic potion.