Zed Head

Sounds like a bad voltage regulator, or something is connected to the Charge light circuit that should not be. The external regulator controls the Charge light. Charge up the battery, see if the Charge light is on, then unplug the voltage regulator. If the light goes off you probably have a regulator problem. If it stays on you have a short somewhere.

This is how dry it is around here. Barbecuing makes me nervous. https://www.oregonlive.com/clackamascounty/index.ssf/2018/08/oregon_homeowner_trying_to_kil.html

Did you turn the radar off? Did you leave the brown or white wire touching any ground points? Take the ignition switch apart and see if it works correctly without the key. You can work the electrical switch with a screwdriver when it's apart. Charge up the battery then disconnect the things that might be draining your battery. You have too many weird problems to pick just one cause. The engine starts but won't shut off, the battery dies when sitting, the charge light is on when the engine is running. That could be three separate causes for three problems. Start troubleshooting with a fully charged battery.

It just gives you the final ratio of the transmission/differential combination. I use first gear because that's where people notice ratio problems first, taking off from a stop. Passenger cars are usually around 12 because their tires are the same size. A truck would have much higher ratio. Nissan went to a 3.9 when they changed first gear to 3.062, and ended up in the same general spot. They went to a much higher number with the heavier 300ZX. Early 280Z (2975 lbs) - 3.54 x 3.321 = 11.76 Late 280ZX (2824 lbs? [probably 1979]) - 3.062 x 3.9 = 11.94 1989 300ZX (~3000 lbs?) 3.321 x 3.9 = 12.95 Got some weights from the internet and they don't really fit. So who knows why they changed the ratios.

Is it the stock Nissan gauge? There is no "CPU" on Nissan stock. Mine says CHG. If the light is on it means that there's a problem with the charging system. "New" doesn't mean good. Check those new parts. You might have a short that is "backfeeding" the ignition system.

Which one? Sounds like a possible voltage regulator or alternator problem, or ignition switch. You need to give more details about the car and any modifications you've made to it. You have some weird stuff going on. And the stock Nissan volt gauge doesn't have a "CPU light" so it's not clear what you're talking about there. Plus, if the car wouldn't turn off how do you know the battery is dead? It's still running, right? Details...

Accelerator pump seems reasonable. I was going to ask also if it was new Holley 390 tuned for the L series or if it was a used 390 from some other vehicle. https://www.summitracing.com/parts/hly-0-80507-1/media/instructions

I have some spare forks if you can't find one.

That's the wrong part. You need #57. Two for each side, about $12 each. Less than $50 total. http://www.carpartsmanual.com/datsun/Z-1969-1978/axle/rear-suspension/57 https://www.courtesyparts.com/oem-parts/nissan-bushing-link-55541e4100

I think you'd be fine with a 3.7 rear. Yours has a 3.321 1st gear. 3.7 x 3.321 = 12.29. With your cammy engine a little more ratio might make it a nicer drive from a stop. And with a smooth running engine even the four speeds are pretty nice at higher RPM. I got my 5 speed mainly because my engine was running rough and I didn't realize it. High revs seemed to be working the engine. After I got a better engine with better parts I often forget to shift in to 5th. You won't really know until you get it on the road.

Not really enough to go on. Unknown engine, Holley 390, AZC manifold. Is it the stock L24 engine? Is the cam stock? Cam timing, ignition timing, etc. all can affect performance. Get as much technical info together about your parts as you can, and check the settings against the specifications. It might just need a thorough tune-up. Here's a link to some service manuals. Links are on the right - https://www.classiczcars.com/files/ Welcome.

The very easiest way is to look at the exhaust system hangers. The 81-83 ZX transmissions have one, the early 5 speeds have two, one on each side. The early 3.321 1st 5 speeds came with a 3.54 ratio rear. Here's an 83 ZX 5 speed...

http://zhome.com/ZCMnL/tech/240SX5spd/transmission.htm 3.321 1st... And another project! Whee.

The bearing seat gets gouged when the races get cocked. You can't beat a gouge in to submission. They just get stronger.

Doesn't the gear center on the carrier? "Hub centric", precisely machined. The bolts just stop the gear from spinning, that's why people use bushings to sleeve the small bolts in the big holes. Pretty common. And it's the torque force of the bolts pressing the gear face to the carrier that stops the spinning, in principle, by friction or locking "asperities", so the bolts aren't really supposed to see anything but tensile force. Some manufacturers actually use "thread" locker at the surfaces, between the gear and carrier, as a kind of glue. Interesting problem. Forces you to really think about how bolts and threads work, and the parts they're used on. What transmission used would be the key for ratios, I think. You might check your clutch plates while it's apart. I have a Ford LSD in my truck and they're known for wearing out the plates and going "open".

One other way to get screwed up, if you do the above, is to find that the 88 CLSD is actually a VLSD. 88 was an odd year and had both apparently. I can't tell from your pictures what you have. They use different axles. I've heard about the bolt size problem. If it was other way around you could use bushings. In your case, you could use thread inserts. It would be quite a test for them, but, in principle, they should work. If you can hit the torque number, they should be fine. Aesthetically displeasing of course.

Somewhere in Abate's content he has gone through all of the same problems you're having, and done all of the things that you're doing. It's an old story. CO eventually helped get it straightened out but I can't find the specific thread posts. The bearing races were getting cocked during insertion. Not obvious, ironically. @Captain Obvious Old news, it's out there somewhere. https://www.classiczcars.com/profile/30168-matthew-abate/?do=content&type=forums_topic&change_section=1

The HEI module works the same way that the Nissan module does/did. No reason for it to produce more EMI. Are you sure that the noise is RF noise from the ignition system? And are you sure it's from yours. You can get it from other engines in the vicinity. Could be a bad fan motor also. See if it's still there with the engine not running.

For that area, yes, I'd use Nissan's bushings if you can find them.

I think that you're probably right. If he had told the whole story from the beginning it might have been more clear. Polyurethane is over-applied for the Z's I think. The sellers are just replacing rubber willy-nilly, no deep thought about appropriate usage. More parts equals more money. It probably is falling apart because it has dried out and the lip is too think for the gap. I'd replace them with stock Nissan rubber.

That's interesting. I found it in the 1972 FSM but checked 1976 and it's gone, they changed the instructions completely.

I found one of the old threads/articles about that custom tool. Click the arrows to go back and forth, it's a pictorial. Search the name and you might find more. Somebody was loaning one out for a while.

He did. We did. We know what you're talking about. Those aren't supposed to be there. They are not bushings. They are rubber seals, to keep dirt and moisture out. Somebody added them to your car, they are not normal.

I think you might be better off to swap the carrier and LSD in to the 88 R200 housing, since the pinon gear depth is already set for the housing. JMortensen says he often gets away with no reshimming when he swaps carriers, if I recall his past posts right. Otherwise you have to get in to pinion bearing preload and crush bearings and all that, and might have to reset backlash, as I understand things. But that's really just more fun. Are you sure there's not a V8 hiding in your garage somewhere...

Resto mod. You'll need a custom "dog bone" cross piece to fit those fins. Plus the axles and other goodies. It's a project. What's the ratio?