Zed Head

Does it run better than with ported vacuum? You've described what you do but not why you do it. Edit - there's a ton of discussion about it out there but most (all so far) of the reasons given by the various internet participants are opinion, many based on peronal theories about how engines work. Haven't found a solid explanation for why it was developed in the first place. I'll keep looking...

People fill tanks with water then empty them to be sure there are no fumes inisde or use dry ice to get rid of oxygen and fumes. But, really, if you empty the tank and let it dry until you can't smell gasoline you're safe. If your nose works. I've had a chemistry class and have a good nose though so feel a bit more confident than some might. Stick a fan on the fill hole and let some air pump through it to dry it out and see how you feel about it. Then throw some lit matches at it to be sure.

It can be if you jump certain pins on the EFI harness. 1977 has the combined EFI and fuel pump relay that controls the pump and the injection EFI system. I ran an engine on a stand by doing that. There are probably instructions out there but it's probably simplest to just look at the wiring diagrams. Or, you could remove the combined relay from the dashboard and plug it in separately. Let it hang. Probably easiest. I've mentioned this in the past also but I had found that my EFI engines would not start if the tachometer was disconnected. That problem went away after I switched to a GM HEI module ignition system. In short - remove the combined pump and EFI relay, separate the harness from the dash, plug it in and see what happens. Then unplug the tachometer and see if it starts. If it does, you should be good to go. Worst case, the shop has to push.

Find a local racer's forum. Maybe PIR has one.

Actually this could mean that the power transistor or the wiring is bad. No offense but can't tell if youre using twists and electrical tape, or crimps, or soldering. You can check the control wire from the computer directly at the power transistor connection. That will tell you if the computer is controlling the power transistor. I'm not sure which of the three wires is the control wire. But you can see from the circuit diagram that one pin is ground, one is battery voltage with the key on, and the other is the control wire from the computer. I think that it might be a 5 volt square wave, which should flash a test light, I think. That's what I would test. That tests the computer directly. If you are positive that injectors are squirting that means the computer is getting what it needs. You'll want to be sure the injectors are squirting, the computer won't squirt or spark without the right inputs to the computer from the distributor. At the PRW2 connector frm the computer, ID the ground, ID the battery power, the one that's left is transistor control. Test it for flashing when trying to start. It might even show 5 volts, off and on, if you turn the engine by hand with the key on. Not sure. @cgsheen1 has expertise with the ECCS's. He might have some thoughts.

Not familiar with the "fuel pump relay mod". Maybe you blew a fuse. Have you used a test light or meter to check for power at the coil with the key on? Do you have the service manual? You can download it here, linked below. The ECU has diagnostic trouble codes through the lights. Open the EFEC chapter. https://www.classiczcars.com/files/category/15-300zx/ Continued...

That sounds bad. Did you take a knock to your head? Hope things work out well.

This might help. Thanks to Blue 246. https://www.atlanticz.ca/zclub/techtips/fusiblelinks/index.html

Reset them to the narrower gap and the question should be answered. I can't recall ever seeing a Canada spec 280Z. Hard to say. Maybe they used the older ignition modules with the ballast resistor.

But this one is. 506 picture running drivable project 71. Mad Max hubcaps. https://bringatrailer.com/listing/1971-datsun-240z-354/

Doesn't look like they've submitted it yet or BaT rejected it. It's not there.

Can't remember if your ignition system is stock or not. 1978 is high-energy, big gap. Why did you decide to mess with the spark plugs if everything was working well? Your post of March 16. Is it running oddly? If you have created a misfire with a big gap it should show up on your AFR gauge. But a misfire will also cause non-smooth running. I'd guess that the engine is running differently for some other reason than plug gap. Maybe you bumped a hose or something. Maybe a mouse has moved in to your air fillter box. Worth a check. It happens.

Hot dogs!

Yikes. $31,250. https://bringatrailer.com/listing/1978-datsun-280z-191/

Do the illustrations in the Body chapter have any value? 1972 -

I have learned to anticipate repairing or correcting aftermarket parts before I install them. Some repairs are simple like chasing threads, other more complex like disassembling, cleaning, and reassembling. The fuel level function can be tested before installation, no need to soak it in gasoline. I would guess that it might even be possible to swap parts from an aftermarket assembly over to an OEM sender to get it to function correctly. For the money involved, it might be worth the time. Buy a cheap aftermarket assembly for the parts.

The best way to test the injector circuits is with a fast-acting light like a NOID light or with a spare injector. If you find that the injectors aren't being opened by the ECU then you can focus on that. But you might find that the injectors are being "commanded" open but aren't. They can rust shut. Or maybe they are opening but they're squirting water. Maybe you put 5 gallons of diesel in by accident. Just kidding but the point is that you seem to have everything you need except good fuel squirting. If it starts with starting fluid you have spark and proper timing. Is your cold start valve still installed and connected? It's easy to remove and you could check that it is squirting good gasoline during the start procedure. You could also install it on one of the injector connectors, I think it uses the same EV1 connector. I've never tried that though. Could be interesting. Don't forget that the hose will be pressurized if you remove it from the hose. If you can keep it connected to fuel but get an injector connector plugged in it might tell you something. But really, a NOID light is the way to go.

Is your tachometer connected, with the inline resistor in place? I had found in the past that my 76 and a 78 parts car would not start if the tachometer was disconnected. It appears to do something to the signal on Pin 1. I never figured out what, but I did confirm it a couple of times. On the 78 I had the tachometer out and on the 76 I had the resistor removed which disconnected the tachometer.

Seems like the main question is "what happened between then and now?" The cracked AFM hose could stop the AFM from functioning, but the engine should stil start for a few seconds on cold start injector fuel. Maybe your spark is too weak. Are you seeing s strong blue spark or a weak yellow spark? You might try starting fluid to see if you can get it to fire for a few seconds. Another possibility is flooded/fouled plugs. Have you pulled a spark plug to see how it looks? I'd do that, it's easy and quick.

Pretty slow lately. Maybe some chest pain will help.

I was being clever to draw out the bot. I actually meant is this a new bot method. I reported one of the posts. Lets see what happens.

Is this a new method?

The app does the calculation for you. "Degrees crankshaft". https://123ignition.com/wp-content/uploads/2023/03/Curve-Tabel.jpg