Zed Head

Is that some sort of orthogonal hammer driver?

Here's a drawing of the part. It's a wedge bolt like the kind that holds the pedals on to an upper-end bicycle. Wedging the part #12 against the case and twisting the rod might loosen the bolt. But, since it's a wedge shape, it will be wedged in there pretty tight. Wedges are powerful things.

Here's the FSM test procedure for 1978. It still uses engine cranking, but distributor spinning gives the same effect. I still think that there is another test procedure out there, maybe in the EFI Guide.

Breaking the Pin 1 circuit might work but the standard method is to make and break the coil circuit. Create a spark at the coil. Pin 1 needs to be connected to the circuit, of course, like it would be on the engine. Somewhere out there I think that there might be an actual Nissan write-up on it. Can't remember.

The three spark test supplies higher voltage to the EFI system than using the starter. Might be a clue. Plus it's quieter. Easier on the brain waves.

The FSM implies that the AFM signal is necessary but it must not need to be generated by the AFM. Since the engine will run with the AFM unplugged. The ECU just uses whatever is on those wires at the ECU connector. Open circuit seems to be enough.

You can get the ECU to open the injectors just by triggering three sparks, with the key on. If the circuit works. You could probably build a testing device with just power to the ECU, some lights on the injector grounding transistors and a voltage pulse to Pin 1. People often run their engines with the AFM unplugged. The base pulse is very basic, apparently it doesn't really need any sensor data. It's the starting point and all else is an addition to its length. Just saying, it's a simple input-output device. A scope would tell you base pulse length but might be more than needed to see if the ECU works or not.

It's just another reference point.

Can't that be measured? I wonder if a meter would show something. I had heard that the top hose was conductive, the black one. Might have got the PVC hoses mixed up. I didn't even know the silver color was a coating. I thought the material itself was silver. And that it was a silicone material. Maybe somebody painted a rubber hose silver on ea6's car and that's not even a Nissan hose. Anybody got a hose laying around and some solvent?

There's a reference to a Hybridz page in this thread that cygnusx1 supplied a while ago, that shows what some of the components do. Not in schematic form, but better than nothing. It's near the bottom of the Hybridz page. The link still works!

Nissan too, maybe. Your local Nissan dealer. http://www.carpartsmanual.com/datsun/Z-1969-1978/engine-280z/piston-crankshaft/21 https://www.courtesyparts.com/oem-parts/nissan-bolt-flywheel-1231542l11

I'd beat it on the garage floor, a rock, or a tree to break the stuff loose. Plug the ends if you don't want it to fly out.

ea6 is right, I believe. And PAtcon is right about the flame arrestor but it's in the valve cover hose. That silver PV hose is pretty big in diameter. Just stick a screwdriver in there and dig out the crud. And yes, they came in silver. you removed original paint.

It was a grammar joke. Nerdy. You said "figment" instead of fitment. Figment of imagination....

Are you sure you didn't just imagine it?

As far as the main inputs and outputs what would be different, to cause one to not work in any certain car. The fuel curve might be different, to work better with an automatic versus a manual, but the Pin 1 signal and the injector opening and closing should not be affected enough to cause major problems. Certainly not starting problems. These things aren't even computers, as we know them today. They're just parts in an automated system. Signals and measurements in, control signals out. The ECU can't tell what car it's in, they all look the same to it. The wiring diagrams for the EFI system don't even have any of the typical "auto" versus manual dotted lines, like the full car diagrams do. And. if you look at the chart in the first post, NMC and JECS don't even distinguish between them in the same way. JECS uses the same number for all of the MT cars, except for 75. NMC switches after 76. No rhyme, no reason. Also, didn't know this myself, there is no Federal 1975 car, apparently. I don't think that's right but the chart has nothing listed. Do all 75's have catalytic converters and EGR?

I tried ECU's from 75 to 78 on my 76 and they all worked. Might be that there's something wrong with that A11...000 ECU. I was lucky enough to have my car when lots of spare ECU's were floating around from a local guy, and I had a 76 original and a 78 parts car. All Federal models. I always tried spare parts in my car to be sure that they had value.

Looking at the diagram you can see that if there's power on both sides of the fusible link then there should be power on at least one side of the EFI relay. You can also see that the ignition relay actuates the EFI relay. Check that power source. That's the basics of troubleshooting with a meter and a diagram. Power here?...check...power here?...check... Might be that the 76 dash transplant brought some 76 wiring with it. Who knows....

CO knows the 78 system better than most. @Captain Obvious But I would doublecheck both of the fusible links that supply the EFI relay. That tachometer problem could be many things. But with the key on you should definitely see battery voltage at the injector connectors. The system works by grounding that power. So, no power, no injection. I like to work from wiring diagrams myself. You can see that power to the ECU and power to the injectors each has their own fusible link. They would be the green ones connected directly to the battery positive. Not in the fusible link block, but separate, hanging, sort of, by the battery. With a plastic connector that often gets connected backwardly to the negative connector which is identical. Nissan faux pas...

You might get your problem resolved if you can get to talk to the owner of the shop. You've probably been talking to somebody low in the organization. But, if you make fun of the people you talk to, ridicule them, call them stupid, and/or tell them how angry you are, they'll just tell you to get lost. I don't see the Item number on the paperwork you posted (I didn't look very hard). You didn't say if it was the correct number for the 2+2. 4 seater. It's probably on the box. If you find that the Item number is incorrect, it will make things easier. That's a miscommunication. If the item number is correct then they have to figure out who put the wrong parts in the box. I would go through all of your communications with them from the beginning and see if you can find a place where a mistake was made. I've always found that if you can show the path to a problem people will accept their mistake more easily. But, you might find that you made the mistake, so be ready.

So it idles well, and it's not running rich? Problem solved? You should measure the TVS values at the ECU connector like the book shows. The ECU can't see those contacts, it only knows what the wires tell it. That is a Fuel Injection Corp reman. Sold by MSA. They take the Nissan model number off of the original. I had one of those and it ran rich at idle. Couldn't pass emissions with it, even with the idle air bypass wide open. It worked great otherwise. Not really sure how they verify that their remans work correctly. I don't see the resistance numbers for the AFM. 100 and 180. Numbers, numbers, numbers....

You don't have the old set to compare to? Here is the web site of the company they bought from. Based on the box in your picture. There should be an "Item number" on the box. https://www.accmats.com/commerce/1979/Nissan/280ZX/Flooring/4586/

You made your point. The posts you're quoting are over 5 years old.

What brands are the two that failed and how did they fail? What broke? Pictures always good.

The TVS being stuck on wide open can cause wet plugs also. You can check that at the ECU plug also. I assume that your coolant temperature sensor reading was at the ECU plug.