Captain Obvious

Flak? For what? I think your contribution was nothing but valuable. Maybe the forest was missed for the trees... The differences seen between power supplies on the bench and in-car use may not have been voltage at all. It may have been temperature. Warm bench in the shop vs. cold dash in the garage? I will refine the zener regulator voltage though. I've been inside three 77 clocks and they all used 5.1 volt zeners. You should be able to operate the clock down to just barely above that point. I don't know about other years, but I would suspect they used the same value on all of them.

:laugh: Haha! You made me snort! BTW - I'm not denying that this phenomenon exists, I'm just saying that Datsun (tried to) took steps to prevent it. I don't have an explanation as to what is going on, at least not a credible one... My money is currently on Blue's relativity suggestion.

Haha! Combine unusual coincidence with the depth of knowledge and experience here and look what happens! Nice pics by the fire truck. Hope they have a good trip home. They've got quite a drive ahead of them, and I hope they don't have to drive the Z through the snow.

Good. Hopefully they'll see the pics then. I've got more if there's interest. We made contact over at zcar.com, but that forum is pretty hurting at this point. Not to forum bash, but I log in very rarely and might not even know if I've got a private message for six months. If the website even does send out a message, it usually gets hung up in my spam filter. My part of the world isn't nearly as pretty, so I spend more time online. But I spend more time here than Z other forums. I agree... Good people. I was out there on a non-Z related event and was extended a gracious invitation to spend the day at that SCCA event. Mixing Z car stuff with the other non-Z events was a bonus that I really enjoyed. A nice respite from the norm. If they stop over, let them know I was asking for them.

I tried to get pics back to the owner, but they didn't seem to spend a lot of time online and contact was spotty. After being there, I understand though... If I were them, I'd be spending all of my available seconds outdoors as well and not in front of a screen. Do you know if they are members of the forum?

I've got some neat shots of the blue 73 that I took at an SCCA event this past summer. It was a great Z day for me as well! I'm 99.5 percent sure it's the same car/owner. I'll confirm the other 0.5% once you post a pic.

Shouldn't be... The non-quartz control board is shunt zener regulated. Unless you're trying to run it off a pair of D cells, it should be just fine. Even a 9V battery should power it just fine for quite a long time. Of course the quartz movement could (should?) be more accurate, but not because of the input voltage variation.

Would be interesting to use the timing light while the problem is occurring, but since it only occurs under load, that's a little tricky. Would add value to see if the timing light was skipping beats at 2K when under load, but might not be feasible. If the wires are long enough, maybe run the timing light wires out of the engine compartment and into the pass side window and take it for a drive while a passenger mans the gun? :laugh: You wouldn't be as concerned with the absolute value, just that it was consistent, steady and not skipping beats.

There's some 78 fuel pump info in this thread: http://www.classiczcars.com/forums/fuel-injection-s30/50487-runs-nice-few-min-then-rough-then-kills.html Starts about halfway down or so?

Very broad brush, but often... Low RPM miss is ignition. High RPM miss is fuel. Your experience with the choke lever and nozzle level seems to support that broad brush. I'd be looking for something electrical.

I'm not from that part of the world so it's speculative, but I've been told you never slow down, you never grow old.

I saw that first sign on Craigslist in one of my occasional trolls. It's close to me so if you want it, I can be local eyes to check it out for ya. [ATTACH=CONFIG]67565[/ATTACH] And there's no price In the ad... If someone contacts this guy and gets a price, let us know, OK?

Duh. Pennsylvania of course. The rest of you guys have recto-cranial inversion. :laugh:

Well if you ever decide that you would like something a little more vintage, I've got a 77 that I'd probably be willing to trade. Just let me know... I'll be holding my breath.

That's awesome! I've got three times that mileage on my Z and I consider it "low" compared to it's siblings. You wouldn't happen to be original owner, would you?

Awesome! The knowledge in this place is amazing!!

I heard that the design was done for North America and the RHD stuff was an afterthought. :laugh:

Here's some of my lock experience. Some of the pics might help? http://www.classiczcars.com/forums/misc-s30/44869-lock-rebuilding-internal-parts-ignition-doors-hatch.html

30K or 130K?

Sitting on a leather something... Briefcase? Chair? Wallet?

Great pics. One thing that was amazing was the amount of mirror image they did for the RHD cars. Two completely different cars from the dash forward. One thing that caught my eye, however, was that they did NOT redesign the center console. They used the same center console and ebrake assy on both RHD and LHD versions.

Another tip. Make sure you take the gas cap off and release any pressure in the fuel tank before you go opening the system. If you don't you might run into a situation where fuel seemingly defies the laws of physics runs uphill for no explainable reason. Well there is a reason... The fuel vapor pressure in the tank is pushing fuel up that hill. Not that this took me two hours to figure out or anything... :stupid:

Gotcha. On the good side, the fact that the problem persists makes it easier to find. So with what you have described, it could be a huge scope of things. Could be fuel or spark. Anything from an intermittent electrical connection inside the ignition module to crud in the fuel tank blocking the pickup screen. Next time it happens, check for spark. That could narrow the scope significantly. Like zKars described it's a hunt, but the hope is to narrow the hunt as quickly as possible.

My first blush advice would be to start simple. Attempt to determine if the problem is spark or fuel. When the problem is occurring, pull the coil wire and see if you have spark. I couldn't tell from your description... When the engine dies, does it restart or does it just crank and crank and not start?

Probably not directly applicable, but here's some info on how the temperature switch works and it's affect on timing, etc. Might be some stuff in here that helps. http://www.classiczcars.com/forums/electrical-s30/46647-water-temp-switch-what-does.html