SteveJ

To add to what @Zed Head said, the fusible link is like the main breaker in the service panel in your house. The main breaker protects the panel. For your car, the fusible link protects the white/red wire. The first thing I might suspect is the alternator could be shorted. I'm about to head out of the house, but I'll give you some diagnostics later.

Advance Auto: https://shop.advanceautoparts.com/web/SearchResults?storeId=10151&catalogId=10051&langId=-1&searchTerm=fusible link wire O'Reilly lists bulk fusible link wire, but the store selector isn't working so I can't tell if they have it locally.

You should be able to use a ring lug and male lug as a short term. I would advise using fusible link wire in case you still have a short. Autozone lists it on their website. You may search others if they are closer. https://www.autozone.com/starting-charging-and-miscellaneous-electrical/fusible-link-wire/bussmann-14-gauge-fusible-link-wire/32375_0_0

That depends somewhat on the switch and wiring harness. On the early cars, the wiring was such that the headlight switch just completed the path to ground for the headlight circuit after going through the high/low beam switch. At some point (and I don't know exactly when), the wiring and switch changed such that the switch operated on the positive side of the circuit. I don't know what changes there were in the intermediate step between the early Zs and the 72 that drove the production of the E4602 switch. @Zs-ondabrain might be able to provide a little more detail.

Here are the part numbers for the headlight side of the combo switch. The challenge is that the one you need had the shortest production run.

I've started hiring myself out to members of our club for the simple (at least I think it's simple) wrenching and wiring needs of the S30s. I could probably do the S130s, too, if there was interest. Even in my mid-50s, I'm at the lower end of the age range in my club, so I help others keep their Z cars. So along @jonbill's suggestion, maybe if not a relative, a local club member might be willing to turn the wrenches for you, possibly for a reasonable fee.

Jim, this is from the parts catalog: So I would say the transition was around the model year change from 71 to 72.

There is this pricy option from BRE: https://www.bre2.net/mm5/merchant.mvc?Screen=PROD&Store_Code=B&Product_Code=020A04&Category_Code=bre_datsun_accessories

One of my friends has them. He said the passenger side is pretty much useless.

It could also be the ignition switch itself. This is why you need to own and know how to use a voltmeter. Check the voltage at the ballast resistor with the key in the ON position. One side should have voltage. Heck, even a test light would work for this.

How old are the fuel hoses? Cracked hoses can let air in.

Do you still have the electric pump at the fuel tank? Is it running?

Good point. The EGR was first seen on the 73.

From previous posts by @Awk34, it does appear as though he is running carburetors. I remember a few years back at a car show, a young man was asking me about what ECU I was running in my car when I was still using SUs. He didn't understand for a while that the car did not need an ECU for fuel or spark. Perhaps @Awk34 is trying to put a digital gauge in the car to replace the stock water temp gauge. If that's the case, I wonder if he wants to keep the oil pressure gauge. Remember the old days when most of the signals we used were 4-20mA or 0-10VDC?

Check all fuel lines from the tank to the nozzles in the SU to make sure there are no kinks that could restrict fuel flow. Check float levels. Make sure the vent line from the engine bay back to the tank is in good shape and will allow air into the tank as a vacuum will reduce fuel flow. Make sure the carburetors are balanced at idle and at 2000 to 3000 RPM. What block/head? What is the compression on the engine? The detonation could be a separate issue. It could even be crappy, low octane CA gas.

Shunt

I just got my friend's reply: "Fill the air inlet of the impact with air tool oil, connect the air and then blast away at the nut. The oil prevents air from going out of the vanes of the impact, and will produce significantly more torque than just air."

I think this is what my friend suggested. Otherwise, it's probably a matter of bolting the engine to something very solid and getting a four foot pipe to put over the end of a wrench (800 ft-lbs).

I sent an email to a friend who gave another friend some suggestions on this same topic about a year ago. I'll let you know what he says.

Z Club of Texas is in the DFW area with the emphasis on Dallas. I don't think they have activities in Houston. I tried to find a Houston based Z club for someone who was on FB asking early Z questions, but it appears as though the Houston club folded a while back.

The carburetors installed on the car are Weber 32/36 downdraft carburetors. The air filters on those carburetors are typical for that type. The SU carburetors are side draft. The fuel rail definitely isn't stock. The stock fuel rail has a return. On this car the fuel rail is dead-headed going to the carburetors, and the line back to the tank has a redneck plug on it. As for how long the car has been sitting, my 73 has been sitting in my garage for 11 years, and it has less dust on the engine than this car.

The purpose of the EGR is to reduce NOx. Octane won't affect that. A good cat might.

He won't if the person doing the visual knows what to look for. That's the problem with California. You could modify a car to put out only carbon dioxide and water vapor, but if it doesn't have the factory parts, you fail emissions. Frankly, @280zdude could install a MS with an O2 sensor and tune it to have better tailpipe emissions, but he couldn't pass CA emissions because MS isn't CARB certified.

LOCK - All power is off. Steering wheel lock is engaged. OFF - All power is off. Steering wheel is unlocked. ACC - Only accessories are powered (radio, fan, etc.). No engine power. ON - Accessories are powered. Engine components are powered. START - No accessory power. Engine components are powered. Solenoid is energized to engage the starter.

No, the pump primes in the START position. Incomplete information. That's like saying "My feet hurt when I stand up" without you mentioning that you're barefoot and surrounded by Legos.