Captain Obvious

I don't have anything technical to add to this discussion, but wanted to say that I really enjoy the investigative work.

Haha! Yes, it's 50/50, but don't go simply guessing to see if it works or not. If you get it wrong, you will short your "hot in start" signal straight to ground through the thermotime switch and burn something up. At least put a meter on it first and see what the resistance readings are to the case. I built a small relay contraption for my water temp sensor that would fool my stock ECU into thinking the engine was way cold when my key was in START. Provided the extra fuel boost to start the engine. I took it off this past summer when it was hot though.

Nice!! So at the next show, you'll be rockin the T-shirt with the tie? That would be a good look.

Just thinking that your thermotime switch is probably screwed into the block right now and taking it out to test it in a pot of hot water would be a PITA. You could run the engine to warm the thermotime up instead of a pot of water. One side should go open circuit to ground when warmed up. That's the side that needs to go to the CSV. And the side that still has resistance to ground even when hot would be the one that goes to your "hot while cranking" source.

Only the polarity of the thermotime matters. The CSV is just like any other injector and doesn't care. So as for figuring out which side of the thermotime is which... Hmmm. Without having the stock harness to trace? You could put a meter on it and you should have low resistance from both pins to the case ground. But one of them would be a direct short (zero Ohms) and the other pin would go through the heater coil (low, but non-zero Ohms) before getting to ground. I don't remember offhand what the resistance of the heating element is so I don't know how easy it would be to distinguish between the heater and a dead short. Failing that, you could verify low resistance to ground from both pins and then heat the thermotime up in a pot of hot water and test it again. The side with the heating coil wouldn't change, but the side that is supposed to switch the CSV should go open circuit. Failing that, someone with a stock EFI harness should be able to trace the wiring and tell you which side is which. I've got one and can do that for you if you can't get the other two methods above to work. I'm kinda surprised that the cranking pulse width feature from the megasquirt isn't enough. Did you try maxing out the pulse width to 100% at the min temp?

Sorry forgot to point out a detail... You do not need to include any additional connections to the battery ground. The ground paths are taken care of by the thermotime switch itself which connects to the block through it's mounting threads.

That wiring scheme won't work. There are two things wrong. First, you need to connect the correct side of the thermotime switch to "hot in start". One connection goes to the heating coil, and the other connection switches to ground when cold (and goes no-connect when hot). So you need to run your "hot in start" to the heating coil side of the thermotime, not the switched to ground side. The other issue is that since the thermotime switches the cold start valve to ground, you also need to run "hot in start" to the other side of the cold start injector. So one side of both the thermotime and CSV go to "hot in start" and the other sides of both are connected together. Just make sure you get the correct side of the thermotime. Make sense?

Wait... So it is assemblable?

Hahaha!! No, I had never seen that one. Oy, So someone actually has that on their arm? It's only funny because it's not me!!

Haha!! No kidding!! I'm not sure I would! No hurry on the sockets my friend. I'm off the road until next spring. And we all lived to tell the stories. Not only was the map on a napkin, but it was scribbled down AFTER the crawl started! Now THERE'S a recipe for success!

Haha!! Nice grip! I don't think of car tools when I see a grip like that.........

Brass sometimes tarnishes to a blackish color. Maybe they are brass, but are just a little discolored?

Take the red LED out and replace it with a normal incandescent bulb and see what happens.

Last summer I flew 1000 miles to a town I had never visited before to spend a long weekend with a number of Z car people I had never met. Heck... I even jumped blindly into cars with some of them and their wives!

You made me go look that one up. Wow... That describes me to a T. Never knew there was a name for it!!

Charlie, When I first got my car, my driver's side seat belt webbing was badly frayed. I have since replaced the whole assy with a donor in better condition and then took the old one apart to see what made it tick. With that in mind, I think I have a plastic side cover sitting in a box that I would be happy to donate to the cause if you're interested. If so, shoot me a PM and we can chat.

What he said. There is no key. As for the splines, I believe they did use the same spline dimensions in both the middle of the shaft and at the steering wheel, so you could reclock the steering wheel if necessary. I don't know if I still have the parts here to double check that, but I'll look when I get a chance and see if I kept them. But that really shouldn't be necessary... Take a look at ST-6 of the 1972 manual, On the lower left, they talk about a punch mark that is supposed too be upwards when the wheels are pointed straight ahead. Maybe you can eyeball the tires to straight and then put the shaft back into place such that the rubber coupler lines up with the steering rack?

Been so long for me that I don't have any memorable info to provide, but I can provide moral support. Good luck and hope it goes smoothly!

Another shot of the finished product:

I cut the splines in on a machine called a "metal shaper". When you mention shaper, most people picture a wood shaper, and it's nothing like that. It's a machine with a ram that moves fore and aft. Cuts a little bit on the forestroke and then drags (but doesn't cut) on the backstroke. Picture the motion of a hand held hacksaw. Vooopah - Voopah - Voopah... You cut one groove to depth a little at a time, rotate the part the correct number of degrees and cut the next groove to depth. Once you have gone all the way around and cut each individual groove, you're done. Shapers are the machines from a bygone era and have been mostly replaced by milling machines. The saying amongst the machinist community is "You can make anything you want on a shaper... Except money." However, there are some jobs like splines and slotting, there's nothing better. I just like watching it work. It's memorizing. Fore and aft. Clickety-clack. Fore and aft. Clickety-clack. A little wisp of smoke off the cutting oil... Here's a couple pics of the setup. This is a pic of the cutting tool that gets rammed into and out of the blank workpiece. The shape of the small cutting tip has been ground to result in the proper groove shape to mate with the male spline on the steering column: Here's the tool mid-stoke inserted into the blank. The round device with the holes in it is called a "collet spinner" or an "indexer". The holes provide the ability to rotate the blank an accurate number of degrees: And here's a pic of the overall setup. Collet spinner on the left side clamped halfass in the shaper's vice, and the shaper on the right side with the ram at about mid-stroke:

Thanks guys! Yes, it was a difficult install. The problem is that the mounting spline dimensions from the 90-96 300ZX is different than what we have on our first gens, so I made an entire new mounting hub for the wheel, cut off the original one, and welded my replacement into it's place. Lot of work, but the end result is that the wheel is in the same location to stock and it's also about the same diameter as the original wheel. So it's not a fancy small diameter racing wheel, but that wasn't what I was after. I wanted something that was leather and had a thicker feel to it, but didn't look aftermarket. I wanted something that it "looks like it belongs", and I like the fact that it came from the Z family. Unfortunately it's not an easy adaptation. Here's a thread about the install with some additional pics:http://www.classiczcars.com/topic/46609-steering-wheel-300zx-240sx-wheel-into-first-gen-z/

I adapted leather wheel from a 1990 300ZX. Significant project and therfore not much help to the OP, but since people are showing off their wheels, I figured I would play.

Those are not the droids I'm looking for.

I hope you know that a post like that absolutely must be followed up by pictures of you modeling said contraption. There's no way you can toss that out there without supplying pics of it in situ.

Haha!! Just like a big puppy dog!! Love it! Sp welcome to the spindle pin club. Now that your hazing is complete, you're a full fledged member. Wish I had the tools you do! Hey... Is that a welded stack of military grade nuts as a spacer?