SteveJ

Now it rings a bell. You'll probably need a 1/2" gasket. I seem to recall that is the size I needed. The extra 0.52 mm clearance is needed to get past the threads easily.

It's been 15+ years since I worried about the wires on the connector. The wire colors in the dash harness, body harness and engine harness are what you need to concern yourself with for colors. Those are the ones listed in the FSM.

Clarify what you mean. Where exactly is the black wire? There is a White/Red wire in the dash harness taking 12 VDC+ to the combo switch. The headlights contact in the combo switch will connect to a Red wire in the dash harness that goes to the fuse box. The black wire in the dash harness is the ground for the headlight switch and the horn.

It's actually been explained many times: And it's documented completely in the FSM in the BE section with the wiring diagram.

Yeah, I knew you were coordinating things for ZCOT for the Autorama. I wanted to make sure Dave made your acquaintance most of all.

So, Dave @grishtxu, are you going to get possession of the car in time to take it to the Dallas Autorama?

Jai, Also consider getting a gasket for the drain plug if you drain the tank that way. I didn't replace it when I drained your tank previously because I didn't have one handy. Perhaps someone on this thread can tell you the right size for the gasket, since I can't remember for the life of me.

It's a simple mistake to misread a diagram. It's dumb to cut wires.

You might try this: https://www.nissanusa.com/about/corporate-info.

We replaced the connectors in 2015, though a crimp could have worked loose.

Pin 18 goes to the negative on the coil and ignition module. It also branches off to a resistor to provide a signal for the tachometer. I don't have the time to dig through all of the FSM, but it is probably a trigger for the ECU to indicate engine speed.

I am not a fuel injection expert, nor do I play one on TV. If you haven't already, download the 79 wiring diagram from here: http://atlanticz.ca/zclub/techtips/electrical.htm It appears that the yellow wire is connected to the blue wire when both coils are energized at Fuel Pump Relay (2). The yellow wire goes down to the connector that you hacked the yellow wire off and comes out as a green wire. That green wire goes into pin 26 on the ECU. It also goes out to the cold start valve and thermotine switch. From there, you need to consult the EF section of the 79 FSM.

I'd hit it.

Interesting. I wasn't thinking about the neutral was floated. I'm so used to the neutral being bonded to the ground in low voltage applications I work with. Of course, shipboard power is usually done in the fashion you described.

I was looking at the oil pressure sensors for the 78. Since they are designed to work with a fuel pump relay, I figured I would try one out.

Thanks for the heads up on this thread, @Zed Head. The OP has read the manual, and I think he understands the operation as designed. The electric fuel pump circuit in the 260Z was designed to run the electric fuel pump only when the car is running. The Nissan engineers intended for the mechanical fuel pump to handle the starting procedure. If you look at page EF-7, you will see that relay identified by number 4 is a normally closed contact. (In the Nissan convention, the bar on the switch is pulled toward the coil. If the contacts are between the bar and coil, the relay is normally open. If the bar is between the contacts and the coil, the relay is normally closed.) When the key is in start, the fuel pump will not run. So, if you want to run the fuel pump while starting the car, here is what I would do. (YMMV) 1. Add a relay that in parallel to the relay labeled number 3 in Fig EF-15. The 85 pin on the relay should be wired to the black/yellow wire coming off of the ignition switch. I would tap into it around connector C-5. That is near the fuel pump relay. Ground the 86 pin. Jumper the wire on the 85 pin over to the 87 pin. At Electric Fuel Pump Relay #1, (This relay has a 4 wire connector) tap into the green/yellow wire and take it to the 30 pin on the new relay. Consider installing a 10A inline fuse before the relay to cut power if something is shorted out. 2. On the existing fuel pump relay #2, jumper together the black/white and green/yellow wires. Better, yet, install an inertia switch between those two wires. That will kill the fuel pump power in an accident. It will be easy to access in the passenger compartment, too. Note: If you convert your car to an internally regulated alternator, you'll take away the signal for the coil on the Electric Fuel Pump Relay #1. You'll need to bring in a switched source for power, AND the inertia switch becomes mandatory. Adding in an oil pressure switch isn't a bad idea, either. By the way, thank you for bringing this up, @Jasonxp. I have to do the same thing to my car for essentially the same reason. If you're lucky, I'll remember to document this with photos.

I have a friend who got bit by the bent LD28 crankshaft, possibly more than once. I think he stopped trying to get LD28 crankshafts.

The correct term is "Idiot Previous Owner" or IPO. Pretty much every Z owner has the potential to be an IPO in some form or fashion. That is one of the reasons my widow will sell my cars. I do not want to be alive and called an IPO.

Whoever installed the aftermarket AC must have decided that he needed to move the TIU to get the evaporator in. Lord knows why he hid the TIU behind the darn thing. Michael didn't even realize he removed the TIU when he pulled the evaporator out a few days ago. He seems very willing to learn, though, so I think the days of mistakes like that are numbered for him. Here's an interesting sidebar. The data plate in his car gives a build date of 3/74. Mine is from 12/74. Sometime in between the builds Nissan relocated some of the components. In my car the TIU and its connector were on the passenger kickpanel, and the fuse box was mounted above that area but a little closer to the firewall. In his car, the connector for the TIU was on the firewall, and it appeared the TIU was probably originally on the firewall, too. The fusebox was mounted about 4 inches lower than in my car on the kickpanel.

Assembling the toolkit has become habit for me due to work. To give a little history, apparently the current owner bought this car from someone who started tearing it down as a project and got bored part way through. If I had of looked at the car in that condition, I would have run away screaming and not stopped until I got to Texas. The owner has the car close to running. As soon as it is running, I will pester him to fix all of the known safety issues (i.e.: right rear cylinder leak, leak in the hose between the bowl and carburetor body in the front carb) before he hurts the car, himself or someone else. I should add that part of writing it all up is to demonstrate going through a series of diagnostics instead of throwing parts at the problem. The issues with starting and running in this case can be resolved with a new battery and a 3.0 Ohm Flame Thrower coil. That's relatively cheap IMHO.

In the 240Z it is. BUT you need to read the full story. I will say that whenever possible, I try to take the Dr. House approach: Patients lie. While not exactly lying, owners misinterpret things and leave details out. The owner thought the wiring was stock. It was not. I used multimeters and the FSM to eliminate everything until the answer was obvious and the results repeatable.

I took the Z over to help someone with a non-starting 260Z. It turned out to be a bad ballast resistor. Ironically when the owner's father first mentioned the problem two weeks ago, that was one of my first guesses. https://fiddlingwithzcars.wordpress.com/2017/01/14/non-start-diagnostics/

Thank you, Guy. I've had some great mentoring from Philip @Blue, Tim McGovern and others. About every time Tim is helping me, I watch his technique and make inventories of the tools he uses to make a shopping list for my tool chests. Fortunately Wendy hasn't made a direct correlation between Tim's visits and my tool purchases. Yes, that's Randy's engine. He showed me a lot of the BRE parts that he bought last year as well as parts for his other project cars. The BRE stuff is like a time capsule. It was fascinating how they devised parts to stand up to the rigors of racing, yet remain serviceable. I'll let you know when I schedule a Datsun day at the house. You can stop and Charles' (@Patcon) place and convoy down. Make it a long weekend.

I don't know the block and head combo for sure, but I believe it is a 280 block with a Maxima head. They said it produced about 180 or so with triples (probably Mikunis). It's not an outlandish build, but it will produce more than the poor, tired lump that's under the hood of my car now.