Captain Obvious

Your measurements don't really make sense... I've attached a snipped from the FSM with some of my notes to help. The measurements you should see depend on if the points are open or closed. If the points are open you should have +12 volts on pretty much everything: a) +12 on both sides of the ballast 2) +12 on both sides of the tach c) +12 on both sides of the coil If the points are closed, the readings are a little different. With the points closed, you should have: a) +12 on the ignition side of the ballast 2) Something a little less than +12 on both sides of the tach and the coil positive c) Ground on the coil negative And I like the spurious "y'all" thrown in there for good measure! :: Just trying to get my attention?

I don't think that's likely. The tach is between the battery and the coil. With the tach not installed, the entire rest of the ignition circuit is stone cold dead. No power at all and no energy to cause any damage. In other words, the points are opening and closing, but there's no power to switch.

You're from Oregon and you just said "y'all?"

Exactly. Even if you had a meter with you and knew what you were looking for, you're not going to defeat it quickly. I've in the past done things like pulled the coil wire off and put it in a pocket. Better than nothing, but I don't consider it very effective. If I were in the car stealing mood, I'd just use one of the plug wires instead and accept the misfire on one cylinder. Anyway, I guess we should consider this thread a warning to keep an eye on our Z's!!

Is that you? If I make it to Zcon, I'll know who I'm looking for?

So you have two condensers? One on the coil positive and one on the coil negative? Well like I said, I'm not sure what they would consider the purpose of the one on the positive side, but it sure won't cause any problems. I'm not so sure about the noise reduction stuff though. Most, if not all of the noise picked up by the radio is caused by the points arc. That little arc is a noise radiation source that is broadcast through the air and then picked up by the antenna. Some noise might be conducted through the wiring, but not much. Anyway, the condenser on the + doesn't hurt. And if you've got two of them, then you're guaranteed to have one in the correct location, right? And for a little electrical theory. It's not so simple as to say that a condenser acts like an open to DC... A FULL condenser acts like an open circuit to DC, but an empty one acts like a dead short. So when you first connect voltage to an empty condenser, it will take all the current you can give it (like a short). But then once it's charged up (full) it won't take anymore current and it looks like an open circuit. And since we're talking theory... I'm really sorry, but I just can't stop myself without including the seemingly converse description of a coil (AKA an inductor). A charged coil (one that has had power applied to it for a long time) acts like a dead short to DC, but one that has just had power applied to it (uncharged) acts like an open circuit. So when you first connect voltage to a coil, it won't flow any current at all, but as time goes by, it takes more and more current until it looks (theoretically) like a dead short. And if we continue to talk about this, I'm going to have to start wielding my calculus. Nobody wants that.

Scott, I'm so glad you got your car back!

Here's the FW dongle description: I think that would work very well. You'd really have to know a bunch about Z's to defeat that. Especially in a short period of time.

Man that car is beautiful. And the garage... I would eat off that floor. It ain't right! ::

What he said. Looks like you guys had a great time. It's so nice to see the camaraderie. One of the things I like about this place!

Woot! Looks great!

Stanley, I will draw a distinction between the earlier points driven cars and the later electronic ignition cars: For the earlier points driven ignition cars, the condenser should be on the negative side of the coil (same side as the points) and the function is to prevent the points from arcing as described above. If you have a points distributor and your condenser is on the + side of the coil (same side as the ballast resistor), then you've got the condenser installed incorrectly. For the later electronic pickup variable reluctor style cars (starting in 74), they started including a condenser on the + side of the coil, and I'm not totally sure of the function. Never thought about it much... Maybe the Datsun engineers felt like they always included a condenser on the coil and were uncomfortable without putting one on there. Somewhere.

Haha! You funny. No quiz for you! Yes, you are correct. The electronic ignition transistor switched coils don't need the condenser like the points versions do. They just have to make sure that their switching transistors are robust enough to handle the primary coil flyback (kickback) voltage without being damaged. Interesting though, the later Z's with the electronic ignition module still DO have a condenser at the coil, but the later model condenser is on the battery side of the coil instead of being on the low side (switched side) like they do in points applications. I'm assuming it's for noise reduction or for a local low impedance source of stored energy. But anyway, that begs the question... The original topic of this thread suggested the importance of a condenser on the coil POSITIVE, not the coil negative. But in points applications the condenser goes on the coil NEGATIVE. So what gives? Blue, was that an oversight on your part, or did I go off and explain the whole points thing in a "normal" application, but miss the mark on the original intent of the thread? I mean, it wouldn't be the first time I answered a bunch of questions that were never asked, but I usually know ahead of time that I'm doing that!

Well I'd really like to meet up with you as well! I've heard that you are in charge of getting all the ClassicZ members together? I'll look into it a little more and then bump the Zcon roll-call thread. http://www.classiczcars.com/topic/50945-zcon-roll-call/

That's excellent that he got it back! I'm so happy for him! Let's just hope that it only took minor damage during the whole ordeal. I guess I ought to put some sort of theft resistant something in mine... I've never given it much thought, but it would probably be a good idea. I like Fastwoman's dongle. Yeah, I said that.

Haha! I'm looking into it... If I do go, I'll be sans Z, but even that would be worthwhile, right?

What the condenser does is provide a TEMPORARY low impedance path for the primary current until the points gap is large enough that the "kick back" from the primary is not enough to arc across the gap. That's the nutshell. Here's some detail. Start with some arc theory: 1) It's easier to establish an arc across a smaller gap than a large one.2) It's easier to MAINTAIN an arc than to establish one in the first place. So if you can prevent an arc from forming when the points are first opening and the gap is very small, you might be able to prevent an arc from ever forming at all because the points gap gets wider as the cam rotates and opens it further. in other words, if you can delay the voltage presented across the points gap until the gap is wide enough to withstand that voltage, then you will not get an arc at all. The condenser provides that delay with it's temporary path. The condenser has to be large enough to suppress the gap voltage until the points are wide enough to resist the arc, but as small as possible since any energy that you use to fill the condenser doesn't go into making a spark at the spark plug. The bottom line is you should use the smallest value you can get away with before you start arcing your points. But here's the tricky part... Remember the part about it being easier to maintain an arc than to establish one? That's where the ignition spark performance stuff comes in. You might think to yourself "Heck, I want the hottest spark possible at my plugs and I don't care if I have to replace my points more often to get it. I'm not going to use any condenser at all and that way, I'll get more energy at my plugs." Well, not true... If you don't use any condenser at all and simply let the arc form across the points gap, you're bleeding energy out of your ignition coil through that arc the whole time that arc exists. So by the time the primary energy is no longer high enough to maintain the arc, you've lost a bunch of energy that COULD have been put into a secondary side spark but is no longer available because it went through the points arc instead. So if you can time it correctly such that the condenser is full at the exact same time when the primary side voltage is not high enough to jump the points gap, then you will get a faster change in the primary current and hence a hotter spark on the secondary side. In other words, the resistance to flow through an already established arc is lower than the resistance to flow though a full condenser. Use the smallest condenser you can without arcing the points. Not only will you not burn up your points, but you'll also get the most rapid change in primary current which creates the hottest spark at the secondary. Quiz on Monday.

Yeah, I think the only year they did that interlock stuff was 74. Big Brother at it's finest. Actually, I think the seatbelts on the motorized tracks that automatically swung into place was the "finest"...

I have no idea at all how the automatic knob mounts. But I'm a little confused about the "why would you want to"... You're thinking you would put a manual knob on top of an automatic shift lever in an auto car? Why?

Haha! Well I hadn't given a lot of thought about going into the knob business. I'm not sure how many shots I'm going to get out of my mold for the shift map. It's certainly not what I would consider a production endeavor. I did cast a few extras but didn't finish the process. Let me dust off the project and see what I got. siteunseen, I believe those knobs that MSA sell are Nissan's current factory offering and are the same ones that show up on ebay as well. They look very nice but it looks like the dimensions of the wood is off from the original and the font on the shift map is different as well. I mean, if your original knob is a mess, then those are certainly a huge step up, but someone who knows what they are looking for would be able to spot the difference. I've not yet seen a highly accurate recreation of the original knob other than what I produced. On all the aftermarket options I've seen, either the wood dimensions are off, the lettering on the shift map is off, or the map is just two dimensional design without the "depth" of the original three dimensional reverse lettering design. I would put mine on a stock restoration and let the show judges see if they can tell it's a repro. Other than the fact that the threads on mine aren't all stripped out inside, I would challenge even the vintage experts to tell the difference.

Not really. That big nut adjustment controls how much friction there is when sliding the rack back and forth, but doesn't really take up any play. I guess if it's completely loose the rack might be able to wobble around a tiny bit in the housing, but that nut isn't what you would consider a play-taker-upper.

LMAO! Great story. No duct tape "racing stripes" down the side hiding externally run fuel lines? Didn't have to resort to that? . . . This time?

Hahahaha!!!! :: ::

To expand a little on what SteveJ mentioned about the white bottle... It's a vacuum storage reservoir. It "stores and smooths" the vacuum generated in the intake manifold and that vacuum is pulled out of that reservoir and used to control the HVAC system. There's a check valve on the manifold side of that bottle so all your vacuum doesn't run back out into the manifold when you floor it. The canister thing is your carbon canister. It's an emissions device who's job is to scrub the air/fuel vapors coming out of your gas tank when the engine is off and store the fumes in activated charcoal which is inside the black plastic canister. It stores the vapors in there when the engine is off and then burns them the next time you run the car. The port on top that is capped is supposed to be capped. I've not studied the system in enough detail to tell you why, but they're all like that. The broken line is a vacuum line and the device it's supposed to be connected to is your FICD (Fast Idle Control Device). The purpose of the FICD is to bump the idle up a little when you turn the A/C on. That line only has vacuum in it when the A/C is on, so if you're not running the A/C it doesn't matter if it's connected or not. If you turn the A/C on however, it will cause a small vacuum leak. Welcome to Z ownership. Buy stock in the companies that make rubber tubing.

Oh yeah? Well my oil is better than your oil. edited it just so I could have the little banner come up like you did. My edit is better than your edit.