SteveJ

There a lot of people posting that something doesn't work because they don't know how to diagnose the system to find the real problem. See "firing the parts cannon."

In addition to what @Zed Head suggested, do you have an electrical or mechanical fuel pump? Do you have a heat shield over the exhaust manifold? Have you thought of insulating the fuel line where it could get heated up by the exhaust? When I switched over to headers, I eventually fabricated my own heat shield to protect more than stock, and when I installed the Patton Machine fuel injection, I routed the fuel line so it didn't run near the valve cover. Both efforts were to protect the fuel system from heat.

I'm not sure what issues you are referring to. I'm pretty sure the 240Z tach will work with a 1.5 or 3 ohm coil. There are no issues that I'm aware of with a 280Z tach and matchbox. A previous owner swapped out the distributor in my 260Z for a matchbox, and the tach works fine. I've helped a friend with the conversion, too, on a 260Z. That tach is the same as a 280Z tach for all intents and purposes.

@w3wilkes provided the link I would have. Dave Irwin did a great job designing the harness. The way I do it takes a little more effort, but I put extra effort into hiding relays and the wiring. I haven't played around with enough cars to make a kit for other people to install.

That should work for body grounding. I did a regular cable because I am me. Check for resistance from the negative battery terminal to the bolts on the passenger side shock tower. It should be close to 0. If it's more than a couple of tenths, then something is wrong with your technique, or there is something wrong with the grounding. Has anything been refurbished or refreshed around the steering column. Sometimes when people try to make things pretty, the paint they used insulates a part from ground.

You'll probably need some headlight relays. Also, you can remove that pigtail so you just have the 9003 connector that plugs right into the connector for the sealed beams. Too bad you're on the other side of the country. I've been installing headlight relays that I hide behind the center stack so no one can see the modification.

ZCON T-shirts are only available after they get shirts out to people who registered but couldn't attend. Other merchandise is available at the Z store at the hotel if the Z store is open. Go to zcon.org and find the schedule to see when the Z store is open.

Why do you want to run the engine?

If you're worried about polarity sensitivity: https://www.superbrightleds.com/cat/ba9s-ba7s/filter/Polarity_Sensitive,No,93,3463: I ended up just replacing all of the dash light sockets in the 260Z with wedge sockets. That way if a bulb didn't light up, I could flip it around, and it lit up. Not recommended for the faint of heart.

Yes, terminals B & L go into the stock plug, and you run a ground to the E terminal. It's not that much different in that respect to the EF-32RL. It's just that the EF-32RL has the ground wire coming out of the top. The downside of having it pre-wired like that is that you need to have the grounding point nearby. If you're running your own ground wire to the adjustable flasher, you can route it to whatever ground point suits your fancy. Make sure the connector for the tach wiring harness is clean on both the gauge and dash harness sides. The turn signal bulbs are wired to that connector. You might even want to take out the tach and test for voltage at that connector. Back from there it would be the C5 (white) connector.

The clicking should come from the flasher unit. With the mix of incandescent and LED, it may not be drawing enough power to click in the flasher though it can still blink when using the turn signals. (Speculation and no proof to back up my speculation) For the bulbs in the gauge, there is a common ground wire. It also grounds the tachometer circuit. The color diagram is missing the dot that shows the junction. That's the common point for both of those bulbs. When the hazards are on, G/L wire should be connected to the G/R wire (left turn signal bulbs) and G/B wire (right turn signal bulbs). That indicates a problem with the hazard switch. It might be letting some current flow, but not enough to light up the bulbs. This is the flasher I have for the turn signals in both my cars. I like that it's adjustable. https://www.amazon.com/gp/product/B0811GTVH2 You can use the same unit for the hazard lights. You would need to run a ground wire. The EF-32RL has the ground wire attached already, but it may be too short to run to a convenient ground.

LED or incandescent bulbs? Electronic or mechanical flasher relays? I hope someone else can help you with the circuits. I'm busy this week, so I don't have as much time to devote to reading the wiring diagrams.

I'm pretty sure it's M8x1.25. About 8 years ago I bought a new shift knob for my 260Z, and it wasn't the right size thread. I took out the M10 insert and swapped in one of these threaded inserts. https://www.amazon.com/gp/product/B002QUZNUO It was a lot cheaper back then, too.

If Jim doesn't want them, I would be interested. I have done plenty of switch repairs.

So I went out to check to see where exactly is the best point to measure ground on the steering column. For the body ground, you can use one of the screws on the scuff plates in the doorframe. Here is where you should put the other probe on the steering column. Be sure not to touch the top ring. As for the body ground, it's in the engine bay. Unless you have a host of electrical issues with your car, the ground should be there. I put a battery cable from the negative to the grounding point because I could. It's on the passenger side of the engine bay, not too far from the firewall.

Do you have any idea if there is a part number difference or just a vendor variance?

You're just not thinking about electricity the right way. Another term for voltage is potential because you have potential (aka stored) energy when the circuit is not complete. Here's a rough diagram of the horn circuit. You go from the positive of the battery to a fuse (not shown) to the horn relay. The electromagnet in the relay is just a long piece of wire. When the horn button is not depressed, there is no current flowing through the wire of the engine harness, dash harness, or horn relay. So you have a long piece of wire attached to the positive terminal of the battery, and that wire includes the red/black wire going to the horn button. Measuring along any point of that wire is the same as measuring at the positive terminal of the battery. The red/black is not at the ground state. When you press the horn button, you are putting the red/black wire at the ground state with the negative terminal of the battery. Now you have current flowing. The electromagnet in the relay is pulling in the contact to sound the horns. You're going from potential energy to kinetic energy because work is being done. So until you press the horn button, you should see voltage to ground at the green/red wire.

As long as you don't have a dash cover glued onto the dash, it's not too bad to remove the tach. It just involves contorting yourself some. I'm in my mid-50s, and I can do it. Heck, I did it a couple of weeks ago when I was helping with diagnosing a car. There are two wing nuts holding the tach in the dash. You pretty much have to lie down in the footwell and reach up to find them . Once you pull the tachometer out enough, you can disconnect it from the wiring harness.

Well, everything I could find about the tach pegging says that the tach is going bad, and for many it's the failure of a discrete component, like in the thread I linked. The good news is this can be repaired. This place fixed a friend's 260Z tachometer about 11 years ago. https://www.bobsspeedometer.com/

Color me unsurprised. There's only so long a manufacturer can support obsolete technology. I'm usually surprised when something is still available.

Hey, @zKars, I think this means you have to show up for ZCON since your car was featured.

I skimmed through the EF section of the 74 FSM. I didn't see that valve, and it wasn't described in the theory of operation on EF-32. I would not be surprised if the vent line from the tank was capped at the tank or in the engine bay.

You're right. I was speculating based upon the dropped performance. That's why I revised to dying tachometer once the voltage readings came back.

He has a 74. I never noticed pressure building up in the tank in my car. Of course, the carbon canister was not hooked up properly.

@Dave WM I think you'll find the part numbers on this page: http://www.carpartsmanual.com/datsun/Z-1969-1978/electrical/electric-unit-switch/section-2/280z. Start around part 31 and work your way down. Be sure to go to figure 2 of 2.