SteveJ

And to add on to @Yarb's post, fusible links are designed to burn up internally and leave the insulation intact. Touch the leads together on your meter. The reading may not be quite zero, and that's the reading you should get when you measure across the links.

Keep in mind that the tests I listed in my long post will work with the car not running. Do those first. Also, post pictures of your fusible links, including clear photos of the bases that hold the links.

I actually keep one of those handy for when I go over to help someone with his car.

I like Auxito LEDs from Amazon. Those are polarity independent. I have never had a problem with them, and neither has anyone else I have recommended them to. https://www.amazon.com/gp/product/B07TQLK6SH

First let's go over the ignition relay and what it does. That way we can trace down the problems. Note: The copy of the 78 diagram I have still shows the relay drawn incorrectly. I think I made the proper adjustments. Color Code L - Blue B - Black W - White Y - Yellow R - Red G - Green When there are two letters, the first is the main wire color, and the second is the stripe. B/W is black with white stripe. So there are two coils in the ignition relay. One coil is energized by the key in ACC or ON. That comes in on the L/R wire. The set of contacts is connected to a W/R wire that traces back to the black fusible link. It goes out as the L/R wire The other coil is energized by the key in ON, and that comes in on the B/W wire. The set of contacts associated with that coil is connected to a W/R wire from a different fusible link. It goes out as the W/B wire. I traced out those wires coming off the relay. L/W Wire Fuse Box (ACC) L/Y Air Con Blower Motor AC Relay Mag Valve Vac L/R Wiper Wiper Power Washer Pump L Radio Radio Power Antenna Sw Rear Defogger W/B Wire Floor Sensor Cal only Fuel Pump Not during cranking Inhibitor Sw AT only Fuse Box (IGN) G Turn Signal Brake Warn Lamp Turn Signal Power Seat Belt Warn Tmr Fuel Lvl Warn Lamp Reverse Lights L Gauges Cooling Fan Relay Fuel Gauge Water Temp Gauge Oil Temp Gauge Tachometer Speedometer Unk Func Kickdown Sw AT only So many of your issues revolve around the ignition relay. Is it bad? Test with a voltmeter. Note: All of these measurements will require the black probe of the meter on a good ground. Unplug the ignition relay. Measure the voltage across the battery terminal. (This is battery voltage.) Measure voltage to ground on each W/R wire. You should have battery voltage at each wire. Put the key in ACC and measure voltage on the L/R wire. You should have battery voltage. Put the key in ON and measure voltage on the L/R wire and the B/W wire. Both should have battery voltage. If all those tests pass, turn the key to OFF and plug in the relay. Put the key in ON and measure voltage at the RADIO fuse and the FUEL GAUGE fuse. Both should have battery voltage. Let us know the results. Considering you said the wipers work, the ignition relay may not be the issue. The dash lights are another issue. The red wire is for the headlights. The G/W and G/L wires are for the dash lights (and running lights including tail lights). Describe the non-start when warm in more detail. Does the car crank? It might be a vapor lock issue. Do you have an AC car? Have you checked the blower resistor? Is the turn signal flasher plugged in? It should be hiding under the dash on the driver's side. The hazard flasher is there, too. The turn signal flasher should have G/Y and W wires going to the connector.

Actually, there wasn't a wire added to the 78. The ignition relays are the same.

RHD Japan has it. https://www.rhdjapan.com/search/category/fuel-system_fuel-pressure-regulators/brands/sard/

You could get a tee like what @Patcon linked and buy a schraeder valve to go into it. https://www.summitracing.com/parts/ear-9616sverl or https://www.amazon.com/Earls-9616SVERL-Male-Schrader-Valve/dp/B01EKUFV90

Instead of cutting into an existing wire... Use what's already in the dash. On the clock, there is constant power at the LW (blue/white) wire. There is switched power at the L (blue) wire on the water temp/oil pressure gauge. You would need to get two male shells (https://www.hi-1000ec.com/product/1133) and two female shells (https://www.hi-1000ec.com/product/1135) along with male pins (https://www.hi-1000ec.com/product/1662) and female pins (https://www.hi-1000ec.com/product/1663) to go in those shells. If the meter doesn't require constant 12VDC, you only need one male shell and one female shell, and you can take power from the blue wire. You can then add a small harness between the dash harness and the gauge. Most of the wires will be straight through, but the wires where you need voltage would also split off to go to your new gauges. The voltage regulator doesn't have any special properties that would give you a better signal than the two wires I pointed out. As long as the wiring isn't corroded or hacked up, what I pointed out should be fine.

You mean like this?

You talk about old gas in the front carb. How old? Has this car been sitting for a long time? In addition to the float level, the path between the float bowl and nozzle could be clogged. I saw that with my 240Z that sat for a long time. How old are the hoses that go between the float bowl and nozzles? (I thought I posted about cleaning out the float bowl, but I don't see the post here or in my history.)

I seem to recall that not 240Zs had the wells for the seatbelt retractors. I do not know if those cars only had non-retracting seatbelts. Of course, with that you show, it supports my suggestion above.

@grannyknot makes some great points. I used a seatbelt system similar to the one MSA sells for many years in my 240Z, but when I changed out the old seat belts in my 260Z, I went with the Wesco Performance Roadster belts (https://www.wescoperformance.com/noname.html). @jfa.series1 found them independently of my posts on them. You mount the retractor on the upper mounting point. While I understand you have already purchased the MSA belts, sometimes you have to absorb the sunk costs and move on.

Repeat as per @Patcon's instructions. Also keep in mind that not many of these gauges are calibrated. You may want to borrow a friend's gauge if you can to compare readings. Also make sure your battery is fully charged when you do a compression test. Cranking the engine can take a lot of power out of the battery. As for the air flow meters, I prefer the second one for the reason you stated earlier. The Unisyn type blocks the air flow, so you have to work fast. I do better working methodically. The "snail shell" style lets you see the effects of adjusting the screws as you turn your screwdriver.

Two things: Post a picture of your airflow meters. Are they the Unisyn type? Personally I don't like them because they block airflow. I like using one like this: https://www.amazon.com/Latest-Rage-5385730856-Carburetor-Airflow/dp/B00CMC57R0 Consider getting a meter like this for tuning: https://www.amazon.com/Actron-CP7677-Automotive-TroubleShooter-Multimeter/dp/B0002LZU7K or a timing light with tachometer and advance from Innova or Actron. That way you have your engine speed with you right where you are tuning. Yes, that's the valve lash. You used cam lobe and rocker singularly. I hope you meant you checked all cylinders. Yes, it's pedantic, but I don't like assuming details. Did you do the other steps I listed? Have you touched the throttle adjusting screws?

You have the carburetors biased too far to the rear carburetor. Let's assume that your jet needles are set properly and are straight. Other assumptions include your floats are set properly, the needle valves function properly, and the carburetors are jetted the same. Verify your valve lash! If you haven't adjusted your valves lately, now is the time. This removes a potential confounding factor. Turn your idle adjust nuts fully in (#21 in the first drawing). Back them out 3 turns each. (Okay, this may be a little rich, but let's do it that was for now.) Get the car up to temperature and turn it off. Make sure the first idle setting screw (#7 in second picture) is not pressing on the throttle. Ensure that the balance screw (#3 in 2d picture) is barely in contact with the linkage on the rear carburetor. If it's pushing down on the linkage, that will bias toward the rear. Try starting the car. If it won't idle, then use the first idle setting screw to get an initial idle. Check the balance, and use the throttle adjusting screws (#4 & #6 in 2d picture) to balance the carburetors.

No. There is an easier things to check first that are more relevant.

From looking at the photos, it looks like you can have heat or defrost but not both. That rules out this system for me.

I'm glad @siteunseen responded to this thread. It reminded me to talk about going to Resurrected Classics. Max did show me many of the products that he is offering, including the emblems. They are plastic, but they look good to me. If you can find someone who can make pot metal emblems like the originals, buy them. I think I still have a couple of old NOS type Datsun script emblems and pillar emblems in my parts collection.

I am using a Walbro pump since they have one that works with my modified fuel system. It hasn't given me any problems. https://walbrofuelpumps.com/walbro-gsl-series-universal-inline-fuel-pumps Also, for your curved sections, I had a friend buy some Sidewinder hoses for the fuel pump I put in his car. They are nice since they are pre-formed with curves. They aren't cheap, but you don't have to mess with them, much. https://www.amazon.com/Universal-Molded-Fuel-Line-Rubber/dp/B07C8YTNPF

Here's a link to the results page: https://www.mecum.com/results/?wp_posts_lot_feature_sort_asc[configure][filters]=taxonomies.run_date.timestamp < 1692403200 OR sold %3D 1 OR bid_goes_on %3D 1&wp_posts_lot_feature_sort_asc[sortBy]=wp_posts_lot

Another reason to get a different fuel rail would be to get one that incorporates an aftermarket FPR more easily.

If you are using stock gauges with stock wiring, the speedometer has reversed polarity from everything else in at least one bulb socket. 🤦‍♂️ Make sure your bulbs can handle reverse polarity. I know that's covered in a thread somewhere on here. I added the bulb to my list after another member told us he found one. I still don't get the obsession with dimming gauge lights. Jeeps with 20+ bright lights give me issues way more often that the gauges.

First do your research on auto AC basics. I'm betting there are a lot of YouTube videos and websites that can give you the basic knowledge of components and their function in the system. As for re-using old components, the drier is DONE. I wouldn't trust it even if it was sealed. Since 280Z driers are unobtanium, that does shift you toward aftermarket. Another factor that should push you toward aftermarket is the fact that expansion valves are also made of unobtanium. Without a good expansion valve, your AC system is a lead weight in your car. The design of the stock system doesn't facilitate using a different expansion valve. Just my opinion.

No need to apologize, @Mike, I think we're just glad that it was good things taking up your time. This site should be a distant third (or further back) behind taking care of yourself and your family.