SteveJ

What have you tested? What were the results?

Go back to what Pete suggested. Check out the filters AT the carburetors.

Pete Thomas also identified another electronic flasher unit in the "Sold on LEDs" thread.

True, I forgot about those.

I believe the ground will be found under the carpet in the back near the right taillight in the 73. However, my memory is fuzzy and is the carpet.

Corrosion in the box could cause hot spots.

The four most likely things I can think of (off the top of my head) 1. Air leaking into the line. 2. The pump is weak. 3. The diaphragm on the pump is damaged. (You would have seen fuel coming out if it's leaking.) 4. You have a blockage upstream. You may want to ensure the lines are clear with some compressed air. Once you verify the lines are clear, you may want to install a fuel pressure gauge near the carburetors to see if you have fuel pressure.

Look upstream of the pump for something that may cause air to get into the line.

You can easily test the mechanical pump off of the car. Remove it. Put fuel lines on it, and actuate the lever arm repeatedly to see if it can transfer fuel from one container to another.

It would be quicker than to find a working 260Z box. That's not the way I understand it. The 260Z distributor is similar to the 280Z distributor in that it has the reluctor and pickup. Some of the old writeups on 280Zs and 240Zs do not always accurately capture what aspects of the 260Z are similar to which car. I selected the 280Z links on purpose. The HEI is a cheaper route than the 280ZX distributor. For the ZX conversion, you need the distributor and the mount. For this one, I believe you only need the HEI. Even if you do need the 280Z distributor, you could swap that in and not have to change the mount.

The HEI would replace the transistor box. You would wire it near the distributor, going to the pickup at the reluctor and to the coil. It's at least an order of magnitude cheaper than the transistor box, too. You would use a writeup for a 280Z, like this one: hei. Here's another one: GM HEI retrofit Here's another: Turbo Ignitor Swap / Upgrade - Chevy HEI - ZDriver.com. Log in at ZDriver.com to see the pictures.

But who wants 60 pound headlights?

Are you certain about that?

By the way, I found the old thread I was referring to: http://www.classiczcars.com/forums/electrical-s30/42398-ultimate-headlight-upgrade-dot-legal-led-headlamps.html

As long as your relays switch the positive and not the negative, you wouldn't need to change that. Give the choice between adding relays or re-wiring, I would choose relays.

I have been very pleased with H4 lights and relays, and I will stay very pleased until the price comes down a lot on LED headlights. Note: To use LEDs in the S30 you WILL need to use relays or do extensive re-wiring. A couple of years ago, someone started a thread on installing LED headlights. He could not understand why they did not work. The LED headlights expect the 12VDC positive to come from the high/low beam switch with a common ground. In the Z, the headlight circuit is wired to provide a common 12VDC positive to the headlight and switches the ground between the high and low beams. Since the D in LED stands for diode, it means that current can only flow in one direction.

This should help you research compatible front pads: S30 Toyota Brake Upgrades | Driven Daily

If it's on its way out, I think you might be able to use an HEI as a replacement.

Seals dry out, especially if they don't have the proper fluid around them. Z Therapy (Welcome to ZTherapy.com) can help you. Send a PM to Bruce Palmer. Meanwhile, where in Atlanta are you residing? Find the Georgia Z Club on FB. You can find out about local events and meet some fellow Z people. There is a car show in Marietta on Saturday that I plan on attending as are some others.

Something is causing a dead short on that circuit. As for dirty wires, Simple Green, Purple Power, etc., work great to remove 40 year old dirt to reveal wire colors. If you have trouble discerning colors, get a friend to help you.

1. Disconnect all the dash harness connections. 2. Use the factory service manual (FSM) to help you match up the connectors. Hint: The wire colors should match on each side of the connectors. 3. As you make each connection, use an ohmmeter to check resistance to ground at the fuseholder. When the resistance drops, you know you found the circuit with your problem. 4. If you don't see an obvious issue, note the wire colors on each side of the connectors that caused the problem and let us know, along with the number of wires and shape of the connectors. (Pictures help!)

Well, that ballast resistor has seen better days. I'm running out of ideas to supply you. However, you may want to read through the troubleshooting guides in the FSM to see if we have been overlooking something. I just can't help but think there is something electrical involved since it dies and will run 5 minutes later. It's like something is cooling down after overheating. It would be great to monitor the coil voltage with an oscilloscope to see if anything shows up then.

Keep in mind that the stock 260Z system did NOT have points. It has a transistor ignition system. See the EE section of the FSM starting on page EE-27. Okay, we may need to move our focus. Verify you're getting a good spark when the car is warmed up. I'm thinking that the stock ignition system may be the issue. Look for an erratic spark with your timing light as the car warms up or any drift in the timing. Check the transistor ignition box in the passenger footwell to see if it's heating up. If so, turn a can of air upside down and spray the box so the liquid hits the box and cools it off rapidly. See if the car restarts easily. Unfortunately Nissan only provided directions to test using a testing box. There is this thread (http://www.classiczcars.com/forums/electrical-s30/49087-datsu-260z-transistor-ignition-system-service-manual.html) that says there is another testing method. You could PM DRBall to see if you can get a copy of it. Was the car initially an automatic? If so, try unplugging the temperature switch. It's a Yellow/White wire that should be around the thermostat housing. I've never played with the stock system. A PO installed a ZX distributor/ignition in my 260Z. I think that's what a lot of people have done.

What ignition system are you using?

Check to make sure the oil doesn't smell like gas. Also, I can't remember, what does the FSM say about the symptoms of a plugged PCV valve?