NewZed

Have you set the two splined ends of the different axles side-by-side and compared? Might be a clue there. Kind of sounds like the taper that lets the axle slip through the locking circlip is too perpendicular. Might have to grind the corners down a bit. p.s. if you find that that is the problem, check the edges of the groove that the circlip drops in to also. I have a vague memory of aftermarket shafts getting stuck in a diff because the ramp was too steep to let the circlip slide over it.

No offense intended but the early EFI systems are actually pretty simple. If you plan to be a real tuner it's a good system to learn on. Download the service manual and the EFI book and do the appropriate tests. If it starts but dies it seems like a fuel pump or pump control problem. http://www.xenonzcar.com/s130.html http://www.xenonzcar.com/s130/fsm.php http://www.xenonzcar.com/s130/other.php

Don't overlook the transmission mounts. They have rubber bushings also that can sag and let metal to metal contact occur. One option that seems to work well is to use an RTz style mount with the diff nose hanging from the GM transmission mount. Then you can completely eliminate the bottom mount and any noise transmission there. https://www.technoversions.com/DiffMount.html I went back through your thread and see that you didn't really address the diff mounting issues. A 1/8" piece of rubber? And you never came back with what happened if you insulated the rear deck. Also see that you've had the diff apart and reshimmed the carrier. Generally, from what I've read, almost any operation on the diff will cause it to be noisier. People have problems even just getting the pinion shaft nut retightened after a seal replacement without creating more noise. In sum though, you're having a problem that most people don't have. My setup with a stock open diff, unmolested, was quiet enough that my main noise concern was the noise the mirrors made in the wind when I had the window open. Not kidding. Overall, you're just doing small things to try to get rid of the noise, with gear oil, and thin pieces of rubber in strange places. It seems like what you have now is essentially the same as what you started with. Make some big changes. Good luck.

Actually it's the shift rod opening that needs to be opened up slightly for the thicker shift rod, along with the gear clearance and the counterbearing work. Here are some references. http://zhome.com/ZCMnL/tech/240SX5spd/transmission.htm http://atlanticz.ca/zclub/techtips/240sxtransmissioninstall/index.html And Hybridz member Nigel had a Motortopia page but it is gone now. I think he might have moved the info somewhere else but can't remember where. @Nigel

This is rational. My diff noise reduced a surprising amount when I lined the back deck with bubble foil insulation. As Sanchez says, the less material you have over the metal deck the more noise will get through.

Actually, what you've done is eliminated all of the wires out to those subsystems as the source of the short circuit. So you can focus on the switch like Miles suggested. Power comes in on single wires, but it goes back to the battery from any metal point on the body, including the steering column. Something is providing the path back right at the switch. But, it must be after the switch contacts, or right at the contacts, since you have to turn the switch on before it shorts.

Unplug the connectors to each sub-system and try again. You might also use a meter and check for continuity instead of blowing fuses. Or put a test light across your fuse terminals. If it lights up there's current flowing. The plastic around the pins at the light sockets melts sometimes and the pins move together and short. Removing the bulb won't find that. And, besides that, removing the bulbs will not find a short circuit. The bulb is actually a resistive element. Disconnecting the each subcircuit will help you narrow it down.

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Also, if you "tighten up" the AFM you're actually reducing fuel. Implying the opposite of a vacuum leak. Maybe a blown FPR diaphragm?

Not so sure that your symptoms point to a vacuum leak. How about fuel supply? Did you measure fuel pressure?

I meant to edit out the part about the gears. When I was trying to get rid of the clunk/thump I found that the more I tightened up the diff mounts the more gear noise I got in the cabin. If you got a stock R200 from eBay then any gear weirdness probably stayed with the old diff. You can't just eyeball the diff mounts. Former owners do weird things and the parts are over 40 years old. You really need to get up close and make sure they're correct. The rubber in the front mount collapses and the metal from the top piece can rest on the crossmember. Metal to metal contact.

Sounds like the gears aren't meshing well. If you don't get the differential isolated from the body you'll hear the gear howl. I'd focus on the mounts. The front mount and the mustache bar bushings. What do you know about them? Do the urethane mounts have the proper metal sleeve inside? Are they compressed against the body? Does the diff have a solid front mount, or a collapsed front mount? You want the path from the diff to the body to be interrupted by rubber or urethane.

Try to find a wiring diagram of a BMW that uses the switch/sensor. Maybe the BMW boards.

I went with those pads on my 76 and replaced them with Beck Arnley after just a short while. They didn't have any initial bite when you first pressed the pedal. Took extra effort to start the stopping process after you felt the pads hit the rotors. The Beck Arnley pads had great pedal feel, very noticeable. But they wore faster and dirtied up the rims. I never tried to lock them up and had 205's on so might not apply to what you're trying to do. If you still have drums on the back you might pull them and check the actual contact patch. Mine only contacted at the ends of the shoes. I could not lock up the back wheels with the parking brake. Very little stopping power back there. The lack of quality shoe options is actually a valid reason to swap to disks on the back.

Metallic or organic? That's a wide tire. https://www.rockauto.com/en/catalog/nissan,1976,280z,2.8l+l6,1209226,brake+&+wheel+hub,brake+pad,1684 https://www.rockauto.com/en/moreinfo.php?pk=298558&cc=1209226&pt=1684&jsn=898 https://tiresize.com/tiresizes/225-50R16.htm

Might be the backing plate rubbing on the drum. Happens if you set the strut down wrong or accidentally hit the plate with a hammer. You'll see rub marks if that's the case.

The suggestions about the pump are good. But your symptoms sound a lot like pressure is bleeding off overnight. Do you have a factory FPR or aftermarket? The typical aftermarket regulators all bleed down quickly. You can check all of the possibilities by attaching a fuel pressure gauge and watching it.

You could have torqued the bolt to 100 ft-lbs by now. Easier than all of the words, probably, and will tell you more. Good luck. p.s. cutting a groove like that is almost exactly what you would do if you were trying to remove a stuck bolt in a tube and heat didn't work. The metal stretches at the groove and the bolt is freed. Same concept as cutting along the length of fuel hose stuck on a barb. It releases before you get all the way through.

Your plugs are either oil-fouled or fuel-fouled. But they are not lean-fouled. Make it leaner. If it doesn't run right because you're too lean then maybe you have a ring-sealing problem. I'm sensing subconscious "I just rebuilt the engine it can't be the rings" thinking. Just a suggestion. And, like others said, get some known plugs in there. Those multi-electrode plugs are gimmicks. The basic concept ignores the fact the fuel-air mixture is moving rapidly past the spark point. It's not a static situation. All that extra metal cools the electrodes also. The electrode (ground strap) needs to get hot and stay hot so the carbon burns off. Gimmick.

The tube is a fine thread precise fit. It's a dilemma. Welding one side will probably warp it enough that the bolt might not fit anymore. Put some thought in to a plan.

The metal tube does not rotate around the end of the arm. The rubber flexes instead. That's why you're supposed to tighten the bolts with the weight of the car on the suspension. A picture of the end would be better. Thread the bolt in and see if you think there's enough metal left to hold the torque. 100 ft-lbs. That's the real concern. If the tube splits and the bolt loosens the control arm will get loose.

White smoke does not come from "lean". You're starting from a bad assumption.

Not normal. What size tires? What type of pad? I think that ceramics have a lower coefficient of friction. https://ctbrakes.com/brakeanswers/friction-compounds/ On the back I found that typical parts stores shoes are meant to fit a larger diameter drum. Only the ends contacted the drum when used. But the back tires still locked up when I was having front brakes bleeding problems.

More fuel or less fuel? "fingering' doesn't really tell much. I don't think the engine will run on one cylinder. So, it's still not clear what you mean. Don't overlook the simple "fouled plugs". When the cylinders don't fire the plugs tend to get dirty. Plug examination usually tells a story. And - bad fuel.

If it was running great before the first thing you should do is to put the AFM back exactly as it was before. "Adjusting" AFM's ruins most of them. Nissan puts glue on the wheel because they're only meant to be adjusted when calibrated then never touched again. One cylinder must be an exaggeration, right? Post a video. Are you sure that you didn't bump something or do something that you think "should" have no affect? Because there's nothing you've described that is a clue. "Engine ran great, worked on engine, engine runs terrible" is all that's here.