Captain Obvious

For me, the biggest issue is missing the ability to have things sorted by posting date. For example, off the home page - enter "Datsun" into the "Category" drop down box - and hit "Search". I'm presented with 368 autos found, and the second one in the list is a 1979 510 which was posted in 2007. It's been over five years... Is this car still even for sale? Might just be me, but I want to see the new stuff up top. I want to see what's been added since the last time I checked the classifieds. And before anyone goes off and creates some fancy new feature to do that... I'll do that part manually. I remember the last time I checked the classifieds. It was a few days ago. I'll just scan down manually until I start seeing cars that are more than a few days old and call it a day. Don't email me notifications. Don't put the new stuff into some "New Listings" category. Don't put fancy banners around stuff added in the last 24 hours. Don't check my cookies and highlight stuff that was added since the last time I visited the site. I'll do the cut-off manually. I just need the ability to have it sorted by the date the item was added to the database. Also if you go back to the home page and enter the same search as above, but this time limit the years "From" = 1970 and "To" = 1978 (like I'm trying to see all the "early Z cars" just like the old forum version), and after that year filtering, I only get five hits (instead of 368). I'm not sure if it's pilot error or not, but there are a lot more than 5 cars from 70 to 78 in that database, and I don't know why they don't come up in my search.

And forgot... Madkaw, The jury is still out for me as to whether your issue is in the lock or in the switch. I'm having a hard time picturing what could cause the momentary "START" return causing problems without having problems with the spring detents in other positions. Especially if it is catching as you suggested. If your lock has never been replaced and you're still running the same one from 71, then I bet it's worn pretty bad inside as well. You'll know for sure where the issue resides as soon as you separate the switch from the lock assy. There are only two tricky parts to the whole thing... First is getting the entire lock and switch assy off the steering column (and it sounds like you're going to have to get over that hurdle regardless of what the problem is), and second is getting the lock cylinder out of it's housing. Other than those two things, the rest is cake.

Mike, All you need to do is lessen the current load on the "START" contact by using a smaller relay to drive the bigger solenoid to drive the starter and there are lots of relays that you can use for that. The most common mod involves using a Ford starter solenoid as the booster to drive the solenoid integral to the starter, but there are other ways to skin the cat. And don't get hung up on the word "booster". I just made that up to describe it functionally. If you search for "Ford" and "solenoid" on here an the other Z sites, you'll get lots of hits. Poke around and you'll find lots of info. Here are two examples I found that included some pics. From Tony D's cardomain page: http://www.cardomain.com/ride/735451/1974-datsun-260z/page-14/ and from XenonS30: http://xenons30.com/starterrelay.html PS - Sorry for the threadjack.

X2 on Rock Auto for the switch. I've got a 77 and I paid less than ten bucks for BECK/ARNLEY # 2011174. I'm not sure if the earlier cars used the same switch as the later ones, so just make sure you poke around a little and make sure you're getting the right switch for your car. I defer to Wade's attempt to replace the switch without taking the whole lock assy off the column. I didn't try, but it looked "possible" to me. If you do have to get the whole assy off the column, you'll have to mess with the anti-theft screws. I don't have any threads to point you to directly, but I do remember that the removal of that anti-theft hardware is well documented. Speaking of that switch... I was having the traditional "turn the key all the way to start and sometimes the starter won't spin" problem. The problem is a well documented failure of the contacts inside the switch. The switch contacts burn up after years of switching the starter solenoid current and that's the reason people install an auxiliary "booster" relay to drive the solenoid. Anyway, I took my old switch apart to see what was going on and even though it's not directly related to your problem, you can see the detent notches around the outside of the switch housing. I chucked up my old switch to cut off the crimped over ring: And here's the inside where you can see the burned contacts. But to the point, you can also see the detent notches in the silver housing on the left side, and if the problem with your car is the switch, then the root is the detent and spring system: For a temporary solution to my issue, I cleaned up the contacts and bent them around a little for better contact and epoxied it back together. Works great. I also bought a new switch, but it's still sitting on the shelf. I don't want to put it in until I've made that booster relay mod because I don't want to burn up my new switch like my old one did. That was nine months ago....

There are basically two parts to the ignition switch assy... The lock section, and the electrical section. The lock section has a screwdriver style post sticking out the back of it that will turn the electrical section if the correct key is inserted and rotated. The electrical section is the ignition switch which is held to the back of the ignition lock assy by two small screws. Do I have a point with any of this? Yes... The point is that the spring that ensures that the "START" position is momentary is located in the electrical section. There are no rotational springs or detents anywhere in the lock section. All of the springing and detents of positions is done in the ignition switch, not in the lock. That said... There are two things that could cause the problem you're having: a) The spring in the ignition switch is not working properly and you need to replace the switch. It's cheap and plentiful and easy to replace. You might even be able to do it without taking the whole lock assy off the steering column. The other possibility is that the lock assy is worn out and what is supposed to be a smooth easy rotation is catchy and notchy in certain positions. This is more difficult to fix and is more expensive. How does the key feel in the rest of the positions? Does it rotate smooth? Can you pull the key out in any positions other than "LOCK"? When you say you have to force it back to the "ON" position, is it a smooth rotation back to "ON", or does if feel like it's getting caught on something? BTW - Here's some of my experiences with the ignition switch assy. http://www.classiczcars.com/forums/thread44869.html and from that thread. The switch is in the lower left: I fixed all my locks and keyed them all the same, but I never went back and updated that thread. There should still be some info in there that can help though.

The hoses on the float bowls are part of the "anti-dieseling" system. When the engine is running, there's a solenoid valve that vents the float bowl chamber to atmosphere through the air cleaner. This means that when the engine is running, everything works the way you're used to seeing with the standard round tops. The trick is, however, when you turn the key off, that solenoid valve de-energizes and the float bowl vent is no longer connected to the air cleaner anymore, but is instead connected to the decaying manifold vacuum as the engine grinds to a halt. This negative pressure above the fuel in the float bowl prevents fuel from being pulled into the engine through the venturi and renders the carbs ineffective. This prevents dieseling after the key has been shut off. I'm not surprised... They look like they've got a good mix of features from both round and flat tops. They've got the round top nozzle adjustability and the independently controllable mixture on the idle circuit of the flat tops. Best of both worlds?

In theory, any changes that you make to the idle mixture and idle speed screws should have the same impact on each carb. The air that is metered by the mixture screw is supposed to be split evenly into the two carbs, and the idle air out from each carb is supposed to be the same as well. In theory at least. That said, if you crank both of those screws fully down, then your carbs should operate just like all the standard Z round top carbs. Use the high speed idle screw (I assume there is one of those) to simulate an idle circuit and sync and tune just like you would any round top. Then once that is done, you should be able to release the high speed idle screw and open up the idle speed screw instead. You will probably have to mess with the idle mixture to get it right at that point, but if everything else is working right, it should fall into place. The theory would be that you run a little rich at idle using the nozzle drop, and then lean it out again using with the idle mixture screw. What else? The anti-dieseling solenoid should have no effect as long as the key is in the "ON" position. If everything is working as intended, then you should be able to completely ignore the anti-dieseling stuff completely. Also, I'm traveling right now, and my internet access is spotty, but hopefully I'll have some access.

The circled screw on the rear carb is your idle mixture screw. It meters air around the suction pistons to lean out the mixture coming through the venturi. The circled screw between the two carbs on the balance tube is your idle speed screw. It meters the idle mixture into the balance tube which is then split for front bank and rear bank. Not having messed with a set of those carbs personally, I would expect the procedure to be... a) Get it to run well and have it be synchronized above idle. For that you would use the nozzle drop adjustment for mixture and the throttle plate opening adjustment for speed. Then Once you have it working above idle, go back and work on the idle performance using the idle mixture and idle speed screws. I suspect all of this sounds a lot easier than it is in reality. One thing to note is that you should be able to get it to idle with the throttle plates virtually closed. Darn near all the fuel/air needed for idle should be coming through the idle circuit and into the balance tube, not past the throttle plates. If you need your throttle plates to be open to get it to idle, then you're not really idling.

Jarvo2, I saw your other post about this and was going to post there, but I didn't because I don't know for sure. Somewhere, somehow, there has to be a way for the vacuum which feeds that actuator to bleed off when the system is not actuated, and I don't know where that vent is. In other words, when the manifold vacuum is not high enough that the actuator is pulling on the throttle linkage, then the back side of that actuator #4 should be near atmospheric pressure, and I'm not clear where the port is that assures that. I asked a while ago above in this thread if that bleed off venting was done in the vacuum control valve, and never heard an answer. So all I can tell you is I believe there needs to be a bleed in that system somewhere, but I don't know where it is. They could have put a bleed vent into the control valve #2, or they may have designed the actuator #4 to be leaky on purpose. I don't know. If I designed it, the bleed vent would be in the control valve and the actuator would hold vacuum. Doesn't mean squat though, since I didn't design it.

Haha!! Don't blame me!! I never even knew what it was until this other thread started... They started talking all French and stuff about halfway down page one: http://www.classiczcars.com/forums/thread47482.html I just figured I would just port that over here and pretend like I knew what the heck I was talking about!!

Yeah, those vinyl stick-ons would certainly be easier to move over to the knob top, but for the knob application, I think I want one of the cloisonnes style instead. I think it would be more durable and "classier" looking. I know it's purely subjective, but any input as to which style above is most appealing?

I'm looking at ebay for Datsun logos that I could use on top of my newest knob, and I'm looking for suggestions as to what would be the best period correct representation for the logo that was in use during the 280Z years. I've found red-white-blue with no surround: red-blue-red with no surround: and red-blue-red with a white surround: Any input from the collective?

Sorry for so many replies... Forgot something. I don't have an original in hand, but I did cut and paste pics side by side. Still need to do something with a color finish:

geezer, Yup, so it does! I didn't read the directions, I just looked at the pretty pictures. Man... can you imagine grabbing a handful of that sucker on a cold Canadian morning? I was going to ask if you had a lathe, but figured that even if you didn't you could come up with an alternative. Send me a PM.

Mikes Z car, If you're asking about the threaded metal base insert, I used aluminum. I was considering stainless but it would have been much more difficult to work with, especially with how much hand shaping I needed to do. The biggest thing I was worried about with the aluminum was how good of a finish I could get, and I'm happy with the results.

Thanks!! I'm not so sure about production though... And this is why: I couldn't make them for that. With alternatives out there, I don't think I could possibly charge what this knob cost me. Of course, mine is way better, but probably not better enough. Diseazd, is the knob you just bought proportioned the same as the original knob? The reason I ask is that there were some of the highly knowledgeable owners discussing knobs in this two year old thread http://www.classiczcars.com/forums/thread37451.html, and the opinion was that Nissan's new offering as a replacement wasn't quite the right shape when compared to the original. I didn't do any more digging than that, but it seems suspect that so many of the forum's heavy hitters unsuccessfully spent so much time trying to find the perfect knob only to find that Nissan has them for less than fifty bucks? :bulb:

Geezer, Cutting the shift map out of that ebay knob sounds interesting. Be warned though... I don't think it's aluminum. I think it's chromed plastic. I might be wrong, but looking at this picture, it's got that tell-tale hue showing through of copper plating they use to get the chrome to stick to the plastic: Not a huge deal, but would certainly make powder coating an impossibility. Would make cutting the shift map out easier though. For nine bucks shipped, you can hardly go wrong for a delicate knob made with shiny finish, and shaped with smart look. Strict and solid fitment, supplies you better performance in comfortable grasp, can help to enhance the spirits of safe driving meanwhile raise the status of your car. :classic:

olzed, Thanks! I'm happy with the shape. Now I just have to get the color right. About the threaded insert? I've got about 25mm (an inch) of threads in there. It's more than I really need for strength, especially since it's metal and not plastic, but that's what I used. My previous inserts were made from brass, but I went with aluminum this time because of the silver color of the base. Here's a shot of the back side of the base where you can see the threaded portion: And I just like this shot because you can see how shiny the base turned out after polishing. I wasn't expecting it to look that clean, but I think it certainly looks to be a suitable replacement for the chromed plastic original. You can tell what kind of camera I'm using! :

Got the chance to work on the metal base. Biggest problem is that I didn't make any templates for the base section, and I no longer have an OEM knob in my possession to compare it to, so I'm winging it from memory! Here's a very rough cut testing on the knob to see if it's even close to looking right. Here's my metal base finished and all polished up. And yes... It's real metal :laugh:: And here's my three knobs all together. I think the base looks acceptable for making it with no template. Haha! Not sure I could do it again, but this one turned out OK: I still need to apply some finish to the newest knob and figure out what I'm going to do for a shift map. I used to have a knob with a Datsun logo in the center. Anyone have leads on inserts that I might be able to use?

Learning as you go is great. Take some time and at least read through the tune up and engine fuel sections of the manual. It will not only add to the learning experience, but it will also help you communicate here. Not sure how to interpret your results with carb cleaner. Usually the typical reaction to a carb cleaner spray around leaks is an increase in the idle speed, not a decrease. Especially if you are running lean. What do you mean by "new" carbs? None of these carbs are new at this point, right?

Progress... I got the rough cut blank trimmed to shape. Here it is compared to my cheap and dirty contour gauge: And here it is cut off from the rest of the bowling pin: Tomorrow I'm going to work on the metal base. ninjazombiemaster, Yeah I remember that thread with the discussion about the shift map. I was looking at yours while it was here and I was considering trying to cast something with it, but I have no idea what I'm doing with that and didn't want to mess anything up. You know most of this is your fault, right? I was perfectly happy with my black plastic knob until I started messing with yours.

I've started my second knob attempt. This time I'm going to really trying to recreate the OEM knob. Step one - Here's my old black knob, and my second knob attempt at the very start :laugh:: Here's what I've got so far. Bowling pin is mounted and first rough cut sizing done: Hopefully more tomorrow! Yes, given enough time, of course! You, being learned in the field of theoretical math and physics, are surely familiar with The Infinite Monkey Theorem. I have one thing to say to you... Ooooo! ooooo! Eeeeeeek! Eeeeeeek!

FastWoman, I understand the juggling priorities issue completely as I am perpetually in the same situation. I've got so many other things I should be doing that I feel guilty when I'm working on the Z. :paranoid: Stack of cement board and boxes of tile? Been there too... Good luck with the project and hope you get your shower soon!! As for the AAR impact on idle RPM, now that I think about it, I have to admit that I don't really know how much of a change you could get out of one that is working properly. I've got mine adjusted such that my idle stays about constant at 800 RPM or so as the engine warms up. If I were to open my AAR up more, I don't know how high my cold idle would go. I suspect I could get a pretty high idle though because you see how small of a window I've got past my shutter when cold. I'm using less than 25% of what that AAR could flow. I bet my cold idle would be 2000 RPM, and as long as it could still close completely, my warm idle should still be 800 RPM.

When you say you have a leak in your throttle butterfly, I'm assuming you mean you have a leak around your throttle shaft where it meets the carb body? Your throttle butterfly is supposed to leak. That's how the engine gets it's air and fuel. But assuming you meant a leaky throttle shaft... I doubt you have enough of a leak to require 5-7 turns down on the mixture nut. If that truly is the case, then your carbs are all wallowed out and need to be repaired or replaced. I can't figure out what you are talking about when you say "the linkage bar/balance screw that shuts the car off smoothly". I have no idea what that means. Might I humbly suggest that you look through the factory service manual and use the same terms for parts that are in the manual. That standardization of terms would make troubleshooting a lot easier. :bulb:

Wade, I championed the exact same theory and it was brought to my attention that the cold clearance spec for the Z is smaller than the hot clearance spec. In other words... It depends on the application. Some engines get tighter when hot, and others (like the Z) get looser. I haven't gone through the analysis, but I suspect it has to do with where the aluminum is. Academic, but thought I would pass that on.