SteveJ

Yellow with the cap - Fuel sending unit signal. Black with the cap - Fuel sending unit ground. It's easy to tell which is which. The other two wires are for an electric fuel pump (unused.

It looks like someone snipped the white wire for some reason. The white wire will need to be connected to the yellow wire. You could pull the yellow wire out of the connector and use male/female bullet connectors to connect the yellow wire to the white wire. Here's the guide I started with 22 years ago. http://www.zhome.com/ZCMnL/tech/280Alt.html

Back in the old days it was not unusual to carry a spare cap/rotor/points. Caps were not made of the nice thermoplastics that you see today and were susceptible to cracking if hit with cold water when they were hot. Points? Well, there's a good reason why you haven't seen points on a new car in a long time. I suspect that I did not have the coil wire pushed all of the way down into the cap, or there was a defect in the cap that I could not see. Those are the two likeliest scenarios. I should have a replacement cap this afternoon with a couple of spares arriving in a few days. I try to stock some caps anyway for when I am working on other people's Z cars.

Well, I think I figured out why she was a little grumpy at times on the freeway. Back in 2008, when I went to look at the 260Z that now sits in my garage, the owner said it wasn't running. After digging through the engine bay for a couple of hours, I found a distributor cap damaged in a similar fashion but worse.

I would think it would be at one of the two screws near the seat spring. That's why I suggested you use an ohmmeter to verify with pressure on the seat/contact.

Sorry, I discarded mine when I put new foam and upholstery on the seats in my 73. It's just for the seat belt buzzer. Unless you also have the sensor for the seat belt (and want to use 50 year old seat belts), it will just cause the buzzer to go off if you have a passenger. The sensor itself should be positioned near the middle of the seat to ensure it is pressed down when someone is sitting on it. If you use an ohmmeter, you can find the contact that is closed when the seat has an occupant.

I finally took the 240Z back out for an extended drive today. That's the first time for it in almost 12 years. We went to the Worship car meet. (Think of a more intimate version of Cars and Coffee.) @gwri8 decided to drive down and visit, too. Plenty of Z cars showed up. I missed getting a photo of one of the 280Zs, though. It was nice to drive the 240Z again. Who is that mysterious photobomber? 😉

She won't hear it from me...for a price. 😉

The funny thing about the parts cannon is that it did work for me once today. My wife's Escape wouldn't shift out of Park without doing the redneck override with the screwdriver. I testing the brake switch, and it seemed to test fine. However, I pulled a WTF and ordered a new one. It arrived today, and I took a couple of minutes to swap it in. She can shift out of Park again without the screwdriver. The funny thing is that I bought a copy of the Escape wiring diagram, and it was pretty easy for me to read. However, with all of the dang modules in the car, you follow one wire around, and it goes into a module. There's a dashed line rectangle inside the box for the module that says, "Logic", giving no freakin' clue what that logic might be. Anyway, she can drive her SUV again. Sometimes the parts cannon will work, but don't bet on it.

Here's the latest list I have after working on the 240Z for a while. I'm also including H4 headlight housings and H4 LED bulbs. I like the Hella H4 housings because they look more period appropriate. The H4 bulbs I listed are polarity independent, so that's nice. White LED (license plate and reverse lights) https://www.amazon.com/gp/product/B08XWWJ4N4 Amber LED (front side markers) https://www.amazon.com/gp/product/B08XWXXPN5 Red LED (rear side markers) https://www.amazon.com/gp/product/B08XWX81ZD Red 1157 LED (rear turn signals and brake lights) - Recommendation removed due to bulb failure Amber 1157 LED (front turn signals) - Recommendation removed due to bulb failure Green LED (gauge lights - green lenses) Recommendation changed to https://www.amazon.com/dp/B092VNXS6H because they are bright and fit under the lenses. Red 1156 LED (rear lights) https://www.amazon.com/gp/product/B00WGAUIR2 Hella H4 housings: https://www.amazon.com/dp/B001G76Q2W Auxito H4 LED bulbs: https://www.amazon.com/gp/product/B07TQLK6SH

All of the lights are fairly easy to change out. I like the Hella H4 housings. Just view the attached video on YouTube (look at the lower left hand side of the image with the link) so you can see the parts link in the description. The Auxito bulbs I used do not need relays, but relays won't hurt. White LED (license plate and reverse lights) https://www.amazon.com/gp/product/B08XWWJ4N4 Amber LED (front side markers) https://www.amazon.com/gp/product/B08XWXXPN5 Red LED (rear side markers) https://www.amazon.com/gp/product/B08XWX81ZD Red 1157 LED (rear turn signals and brake lights) https://www.amazon.com/gp/product/B07YFR8TPT Amber 1157 LED (front turn signals) https://www.amazon.com/gp/product/B08BCCYWKF Green LED (gauge lights - note, you may need to remove the green lens in the gauges) https://www.amazon.com/gp/product/B087JGFK11 Red 1156 LED (rear lights) https://www.amazon.com/gp/product/B00WGAUIR2 Please note that I selected these for the best fit/most light that I could get. Match the lens color for all exterior lights.

So the alternator is charging nicely. The chokes have been dialed back. (Though I accidently went gorilla-mode a broke one of the air cleaner receiver bolts. Fortunately, I had a stash to replace the broken bolt.) I did one more test drive to see how the lighting was in the dark. It passed with flying colors, though I did adjust the headlight aim some when I got home. The heat is working nicely, too. It's time for the acid test. I'm taking it to a car meet tomorrow. It's the first excursion since the Mitty vintage races in 2010 at Road Atlanta.

The stock light switch of a Z will operate the parking lights (Some people call them running lights. I use them interchangeably.) at the first switch position. At the second switch position, both the headlight and parking light circuits are complete. I do have a good stock of headlight switches depending upon the year of your car. Also, I can design a circuit for the 77 and 78 Z to use relays for the headlights. IMHO, the best thing you can do for these cars electrically is convert all of the bulbs to LEDs. This includes doing something like using H4 housings with H4 LED bulbs. I was measuring the current draw with the LED headlights I have in my cars, and it's about 3 Amps total. That's about a third of the current that stock headlights draw. The 240Z has LEDs for all of the parking lights (front, back, and sides). The gauge lights and parking lights combined draw about 2.5A. That is a LOT less stress on the stock switches, even if you don't use relays for the circuits. Is there a reason why you aren't using the stock switch?

If I remember correctly from the Chem E Transport Phenomena class (using the classic textbook by Byrd, Stuart, and Lightfoot - I actually still remember the authors!) that I displayed a mediocre understanding of 36 years ago, for optimal heat transfer, I would think you want the inlet going to the bottom (think about the return on your radiator).

So I added tension to the alternator belt, and the alternator still wasn't charging. Time to load the parts cannon! I fired the cannon and tested with a new alternator. Still no charging. Now it's time to diagnose properly. I checked the sense voltage. It's good. I check the lamp voltage. It's not good. I checked on the positive side of the diode. Nope. I inspected the connector with the jumpers. Some time in the past I moved the jumper to the wrong place. I moved it back, fired up the engine, and saw 14.6 on the voltmeter. So let this be a lesson, kiddies. DON'T use the parts cannon before you make an effort to diagnose thoroughly.

Shake down drive: Choke cables need to be adjusted. Alternator not charging battery. (Going to adjust tension to see if that is the problem. Also spare alternator is available.) Still some leaking from the tank, but it looks like vent hoses are the culprit. I'll have to drive it to drop the fuel level to where I can drain it and drop the tank to inspect. Turn signal cancellation needs to be cleaned up. Oil pressure is great. Water temp is normal. Hard starting after fueling up. I had to hold the gas pedal down while cranking for a while. Choke cable misadjustment? Ran like a scalded dog when it was up to temp. The 5 speed truck transmission (installed by a previous owner) leaves a LOT to be desired aside from dropping RPMs at cruise.

I think the ZX distributors are pretty much re-build your old one since the cores are pretty much gone. The OP said he has a 78 distributor, so he can make that work just fine with an HEI module.

The front lights have dual filament bulbs. One filament has a lower light level than the other. If you look in the BE section, you'll see the original bulb spec. It's 1034. I was just looking at some original dual filament bulbs last night. When you look at the wiring diagrams, you'll see two loops in the bulb where you have a dual filament. There's also a dual filament bulb on each side of the rear panel.

I'm guessing that most of the tachometer problems people have is that they put both black/white wires onto the coil instead of connecting the black/white wire from the ballast resistor to the green/white on the ballast resistor. @beermanpete wrote that up about the Pertronix over at Hybridz.org.

Look up the GM HEI conversion for the ignition. The 280Z distributor can trigger it. You will need to ground the HEI to the chassis to complete the path to ground. That's usually done by securing the HEI to the inner fender. With the 280Z distributor and HEI, you would not need the ballast resistor. Just connect the wires together. If you're worried about reliability, you can just keep a spare HEI in the glove box. I believe there are threads on this board about using a coil designed for an HEI module, but I do not have experience with that.

Wow, doubling down. Yeah, points NEVER fail. They are so fantastic that automakers still use them on cars today. The 280Z ignition box is so unreliable that it only lasts 40+ years. A 240Z owner would have had to replace those "reliable" points many times over in that time. Did you know there are highly reliable replacements for the TIU? Apparently not from your answer. The OP could use an HEI module with the 280Z distributor. It has been well documented here and elsewhere. And he would not need to replace the tachometer, though he could if needed for other reasons.

Wow, I think this may be your most uninformed post, yet.

What do you plan to use to trigger your spark? The 78 used a transistor ignition unit (TIU) mounted in the passenger compartment.

The target for the base model is $40K. I would think the next level up will be $45K to $47K. I'm not going to guess on the Proto Spec.

Of course, not, but we WILL always picture you with a long scraggily beard from here on out.