Captain Obvious

@jonbill , @Patcon , I was poking around with an ignition switch and a meter and found the following anomaly. This is probably related to the "running in the LOCK position" issue you have seen. I cannot identify the smoking gun on the wiring diagram that would exactly cause the run-on issue, but I wanted to throw this out there so others could be aware and maybe come up with some theories. Due to the internal construction of the ignition switch, there are (undocumented) two pins on the switch that get connected together in the LOCK position. Wire colors are B/W and L/R. This is not shown on the wiring diagrams. In theory, it doesn't cause any problem on a stock electrical system, but in reality on a non-stock system, who knows. Here's what I'm talking about:

No way I'm qualified for that. But it has been suggested. Of course, beer was involved.

So interesting to note that the original bolts in that location are supposed to be 45mm long. Been a long time since I was messing with T/C rods, but I do remember there was some pushing and shoving required to get the bolts started. Maybe the extra length helps getting the nut started while you fight the bushings at the other end of the rods? And the two different part numbers that zedhead pointed out? Maybe that's the change from the full diameter shank to the reduced diameter. I have some fuel injection intake manifold mounting bolts, which the fische says are supposed to be the 08134-04510 bolts. And they are the reduced shank, which is not ideal in my application. And thanks much for the offer to send bolts. I hope I don't have to take you up on that. I've got a box of bolts on it's way from a hardware supplier. They're not exactly what I was looking for, but hopefully they will be good enough. There's a problem with you sending me bolts... I need ten of them. So if my box of bolts doesn't work out, I'll let you know. I need two and-a-half early cars worth of T/C bolts. 😄

Glad your pedal stop wasn't snapped off after all. It must have a trick of the camera with the yellow paint showing through the hole that made it look like it was. In any event, happy to hear it was not. Mine was a real pain to fix. Took heat and contortions. One of those simple five minute jobs that turned into a couple hours to completion. So for your bolts for the T/C rods... Assuming the length of the un-threaded portion of the 45mm bolts is not too long for the application, you could cut those down. Just cut them a little longer next time! 🙂 One thing I wanted to point out, however, is that you actually have two different bolt styles in your pic... Undercut shank, and full diameter shank. The difference is the diameter of the un-threaded portion. On the undercut shank, they made the un-threaded portion a smaller diameter than the minor diameter of the threads. That makes manufacturing easier and cheaper to roll the threads and usually doesn't have any impact on how the bolt functions in application. However, in some applications where the bolt shank is used to help locate something, or is in full shear under load, it's often better to use a full diameter shank bolt where the un-threaded portion is dimensioned to the MAJOR diameter of the threads instead of the minor diameter. I think for the T/C rods, you might want to use full diameter shank bolts. Here's a pic showing what I'm talking about. You have four full diameter shanks (circled) and everything else is reduced shanks: So, I'm actually looking for some similar bolts... M10 x 1.25 partially threaded with a full diameter shank. I'm looking for 35 mm minimum, but I can cut them down if necessary. Do you know where off the car(s) did you find those 45mm long full shank bolts?

Oh, and forgot.. Might be the lighting, but your paint on the rear taillight panel looks too light to me.

So... How did I know? My original did the same thing (on top), and the replacement I made on the bottom:

Oh, but beautiful car, by the way!!

Couple comments / questions: Is this remnants of a broken off pedal stop stud? If so, would have been beneficial to address that before the paint. Water under the dam, but less risky of messing something up: And on the front suspension, it looks like you were a little over aggressive with the hacksaw shortening the bolts that hold the T/C rod in place. I think you need a couple more threads to take advantage of the deformed thread nuts anti-loosening feature. Also, it does not appear that the hardware for the sway bar links are the anti-loosening style? I haven't messed with a lot of them, but the sway bar links I've put in have the same sort of deformed thread nuts you have on the T/C bar. Here's what I'm talking about on the front suspension:

What you understand, unfortunately, is not correct. The wrong key should never be able to turn. If it is the correct key blank for that cylinder, it should insert just fine. But if it's not profiled to match the wafers (tumblers) in said cylinder, it should not turn. And if it does, it's because the lock is worn and should probably be replaced.

It all has to do with the way the lock mechanism wears. And it often wears in such a way that a key can get stuck in the lock. As far as getting the stuck key out, I'm thinking that with enough effort and finesse, you might be able to coax the WK back out. I'm thinking that with very gentle pressure while at the same time a couple hard raps on a hard surface (in the proper direction) might be able to move the tumblers inside enough to get the WK out? But honestly, if the lock is that badly worn, it's probably time to replace it anyway.

There is no "casual reversible" telescoping function to the steering column. It's designed to collapse or crush down some in length some in the event of an accident (think "accordion"), but no adjustments in length to make things fit better. I'll take a look at how mine fits together when I get a chance. Yours might be as designed?

Here's the wiring diagram I made for the early cars. The most recent version is Version 8, and. I'm not aware of any errors at this point. As far as I know, it's accurate. Version 8.0 found on page 7 of this thread: https://www.classiczcars.com/forums/topic/69026-1970-wiring-diagram/page/7/#findComment-676548 I think the single RL bullet hanging near your clock might be for the glove box light?

Whoa, whoa... Wait. There's absolutely nothing wrong with that. I made it 1000 miles to Nashville last summer!! 😇

You should be able to disconnect any possible back feeding of the ignition system if you pull the third fuse down in the left column. The one labeled "Flasher". If power is back feeding through the voltage regulator, the gauges will still work and the brake warning lamp should stay on, but the engine should die because the ignition circuit will have no power.

The accessory relay is on the right side above the passengers knees. It shouldn't have any impact on ignition, but if you want to disconnect it to see if the issue goes away, you can do it like this. Note the disconnected four wire connector at the bottom of the pic: : And just to simplify matters, try pulling the top three fuses in the left column. They also should have no impact on ignition. The car should run without them. Pull the fuses marked Air con, Wiper, and Flasher: Just looking for experiments that would help diagnose what's going on.

Couple comments, answers, etc: Of the three thermostat housing sensors, the one on the left is crucial to the EFI. The middle one only has an impact on cold starts (controls the cold start injector), and the one on the right only controls the temperature gauge on the dash and has no effect on how the engine runs at all. The ground wire leading from the AFM base to the distributor is not original. Shouldn''t cause any harm though. Your ignition coil is not stock. I thought the 78 was the first year they did not employ the external resistor for the coil. You don't have a ballast, right? The device on the underside of the BCDD is a solenoid valve that disables the BCDD when the car is sitting still.

@kickstand80 , I was able to download and open the document. Haven't looked at any detail, but I was able to open it.

Nice work. A good rule of thumb: If you're bored and have some time to work on your Z, but don't have a specific project in mind.... Clean some connectors. 🙂

The short story is I need to replace the injectors on a buddy's Z and I gotta believe there are easier to find, cheaper options other than the original design. I've been intrigued by the problem found by some owners where it would fire with five connected, but not six. My assumption is that is only happens on the newer ECU's and there must be some kind of internal current monitoring and limiting. Five injectors don't hit the limit, but six puts it over the threshold and the ECU shuts down in self-preservation mode? I don't know why nowak1981's amazon injectors didn't work, and I'd like to know. I wasn't planning to be doing a lot of flow testing. More electrical testing. Resistance, impedance, that sort of thing.

Yeah, if you think you are the first person to be in there and nobody has messed with it before, then I would close it back up and not change anything. You could move that "back stop" spring if you really wanted to, but I'm not sure it would gain you anything. I'd probably just leave it be.

I'm no expert on the chronology of what Datsun did when, but I have high confidence that your car originally had four-screw round tops installed from the factory. I don't believe the three-screw round tops came out until the 72 "model year", and the Datsun parts manual supports that belief... Four-screws until 8/71 and three-screws from 9/71 until they went to the flat tops in 73. So, that said, I think the four-screw carbs would be the original version for your car. Ztherapy's question about the intake manifold is also something to look at... What number is on your manifold? An E46 is 4 screw, E88 is 3 screw." There should be a part number cast into your intake manifold runner. If that number is E46, then it would have originally been paired with 4-screw round tops. And if that number is an E88, then it would have originally been paired with 3-screw round tops. Of course, at this time, who knows what kind of mix-n-match of parts is on it at this point. Bottom line? For originality, I think you should be running four-screw round tops. But the pair you have pictured have drains on the bowls (which I think is not original). Do the bowls on the installed 3-screw carbs have bowl drains? They should, but if they don't then someone probably swapped the bowls from one pair to the other?

Black oval head Phillips.

That style (without the Phillips feature) was used through at least September 1970. VIN around 10000. I can attest to that with personal experience.