Captain Obvious

I don't have any input into which fuel pump is the best, but you might be able to tell if your having a fuel delivery problem by checking your float bowl levels. Is the problem at idle, or somewhere else?

Mike, I'll take a quality pic and post it here. I'm not sure about your color questions as this is the only knob I've had that has a shift pattern on it.

I've not seen a write-up on "How To Switch From Flat Tops To Round Tops" anywhere. Note that I haven't actually searched the forum(s) for such info, but I've not seen a complete write up anywhere. Do you have a copy of the service manual? If not, download a copy. Looking at your pic (3468), I see a whole bunch of disconnected stuff, but I'm only going to talk about the ones that would cause you big problems: 1) Vacuum port on the front manifold just behind the carb - Used to go to your vapor reclamation system. If I were you, I would reconnect your flow guide valve, but if you choose not to, just cap that port. 2) Holes in the top middle of your balance tube - The one on the left used to go to your anti-backfire valve. If I were you, I would reinstall an anti-backfire valve system and use the port as part of that system. Look for pictures of an earlier round top car for how to connect the anti-backfire system. 3) Holes in the top middle of your balance tube - The one on the right used to go to your idle air control system from your flat tops. You don't get an idle air control with your round tops, so you can just plug that port. 4) Black hose coming out of the balance tube below the two ports mentioned above - That used to go to your temperature controlled idle mixture compensation valve. You don't get that privilege with the round tops, so pull that hose off the balance tube and cap that port. 5) Short nipple sticking out of the balance tube below the two ports mentioned above - That's your PCV valve and it should be plumbed to the crankcase under the distributor near the front timing cover. There's a black braided hose sticking down towards your exhaust manifold... That may be your PCV connection hanging down there. 6) Your EGR stuff is still intact, but it's not doing anything. It is currently disabled and will have no effect. There might be more going on than I see with the above, but look into the above and see what happens. If there's any in particular item you want more info on, just ask.

I'll agree with the consensus above that it's ignition related. Especially if the fuel pump is running and you can smell gas out the tailpipe. If it happens again, you can easily confirm by pulling the coil wire or a spark plug wire and looking for spark while you crank it. Thankfully I have not yet had the pleasure to gain any detailed experience with the ignition modules. Mine (to date) have just worked. But if you can confirm that it's ignition, you might try to grab the wiring harness leading to the module and wiggle it around. If there's a hairline crack heat related intermittent connection in there, the mechanical agitation might be enough to temporarily reestablish connection. Haha!!

I've got a black plastic (faux leather) five speed knob on my 77. I believe it's got the original shift pattern insert. Would a pic of that help in any way? Do you want a nice close up?

Nice work. I'm kinda surprised that they used a plastic tank for that at all. One other thing... looking at the pictures, it looks like there may be the start of a split on the next larger nipple. The one next to the one you already fixed? Is that a camera anomaly or is that one starting to crack off as well?

If it's not stock, one other (unlikely) possibility is that it has a set screw threaded into the bottom to lock the knob in place. If there's no retainer of any sort and it's a plastic insert as suggested above, I'm kinda surprised that the threads in the plastic don't just give way and strip out. That's what mine did and I ended up making a threaded brass insert and glued it in place to replace the original plastic one.

I'm not clear what's happening... Is the knob stuck and won't turn, or is the knob turning and turning but not coming off the shaft? Heh... Yeah, there's a plan!

OK. So now I've heard people talking about problems caused by it cooling too soon. I can shut my engine off for 5, 10, 15, or 30 minutes and it doesn't have a high idle when I restart. Hmmm... Maybe yours is working fine and mine is operating oddly? Maybe it's the way I have my AAR adjusted? When you restart after a few minutes stop and you get the high idle, you can verify if it's the AAR causing the high idle by pinching off the large tube coming off the AAR. Might be hard as a rock when cold, but you might be able to pinch it shut when the engine is warm. If the AAR is open, the idle will drop when you pinch that hose. If it doesn't change, then your issue is elsewhere.

I'm not an expert on the device, but I've not heard people talking about problems caused by it cooling too soon. I guess this would be more of a problem in cold climates. I do remember someone messing with a heat wrap for some reason though... Blue maybe? He's in Canada and would certainly have more potential to need a wrap than people in a warmer area.

Yeah, I suggested a "mistake" above, and what I actually meant was a "seemingly illogical choice to the uninformed". I'm thinking that it was for some ease of manufacturability criteria like what you suggested... They didn't need it for the current carrying ability, but it saved them from having to stock yet another style of wire on the floor? Maybe it saved them from having to stock a different style of connector? I've been poking around the headlight wiring lately and I saw that R/W wire. It's been bugging me since I saw it. I couldn't come up with any electrical reason for the larger gauge choice at that location, and I was wondering if I was simply missing something! You've got an earlier year, right? Did they do the same thing on the earlier ones? Is that R/W larger than the other two?

Thanks for the thoughts, and what you are saying makes complete sense, but that's not what we have here. I'm talking about a point before the two smaller currents join to make a bigger one. At the point I'm talking about, the current for each headlight is independent. The return currents have not yet been joined. The wires I'm talking about go to one and only headlight. Here's a pic of the right side. I can guarantee that every electron coming away from the right side headlight on the thicker red/wht got to right side headlight on the thinner solid red: The three headlight wires come out of the harness, go through the round connector and pass through the inder fender wall on thier way to the headlight bucket for the right side ONLY. (The left side has it's own three wires that come out of the harness on that side, pass through a similar connector and disappear through the fender wall on that side to feed the left side ONLY.) After the two sides join it would make perfect sense to up the gauge, but at the point where I'm talking about every electron coming back on the thicker return wire was supplied through the thinner supply. I'm thinking that it was a mistake in the design dept...?

Yeah, that makes sense at first blush, but think about it... The same current coming OUT of the high beam on the thicker wire had to be supplied INTO the bulb through the thinner wire. I'm talking about after they have split for each side. This is right at the connector leading through the fender walls and into the buckets. I'll snap some pics tomorrow if I get a chance. It wasn't intended to be an easy question... :classic:

If I were doing what you're doing, I would skip the tape completely and just mask a band of high temp red paint on there. Brush a couple thick coats on and it will even appear to have the raised thickness area. Nowhere near my area of experience, but is there some other reason that tape would be better than paint? [snicker!] :classic:

Here's a more much simpler way to describe the issue: There are three wires coming off each headlight. At any instant, two of those three wires have to carry the exact same current... One in, and one out. What possible reason would there be use a thicker gauge on one and only one of them?

Thanks for the thoughts guys, but I don't think it's either of those. Let me rephrase with just a little more detail... Way up by the headlights just behind the radiator mounting plate, there are three wires leading to each headlight: On the right side, the three wires are a) red/white (red with a white stripe), red/black (red with a black stripe), and c) solid red with no stripe. On the left side, the three wires are a) red/white (red with a white stripe), red/black (red with a black stripe), and c) red/yellow (red with a yellow stripe). On both sides, the red/white (red with a white stripe) is a thicker gauge than the other two. Why? Why? Why? SteveJ, I believe you're thinking of the white/red (white with a red stripe) coming from the fusible link to the combo switch? That one comes out switched out of the combo switch as solid red and goes to the two fuses in the fusebox. Coming out of the fusebox are the hot wires for each side. Right side gets fused solid red while the left side gets fused red/yellow. I'm not talking about any of that... I'm way up by the headlights talking about the red/white, not white/red.

McMaster has a few possibilities? 75895A26 - Super-Thin Surface-Protection Tape -Good to 300F 7800A11 - Super Wear-Resistant Slippery Tape - Good to 500F

Glad you got yours figured out! Now that you've done that, I've got a simple question about my headlight wiring and your thread title is so perfect that starting another thread would be a mistake. (I've been wanting to ask, but didn't want to distract anyone from you...). I've got a 77 and I want to know why the red/white wire leading to the headlights is a thicker gauge than the other two headlight wires.

Heh. I suspect there are very few 73's or 74's that still have all the emissions stuff still intact. Congrats again on the new purchase! If that body is as good as it looks, then you got a real nice one there!

Yup. I bet when your cap melted, your shaft shifted a little. I'm trying to come up with some sort of test to check for alignment quality, but I'm not coming up with anything simple that wouldn't require special fixturing. You can't roll the stalks on a table and look for wobble because the thumbscrews aren't round... How about pulling one of your domes off the top, screwing in the stalks one at a time, and then flipping the domes open end up and measuring the distance between the jiggly bits and the inside of the domes at a couple different locations? It's crude, but if it might be accurate enough to see a difference between the good damper and the questionable one. Of course, all of that is academic... You need a new damper stalk. I don't have anything for round tops, but I've got spares from flat tops... If you do the legwork to figure out if they're the same or not, I'd be happy to send you one if they are the same.

The projected tips don't stick down that far... I can't imagine there is any significant increase in CR. Could be wrong, but I would have to see the numbers to believe it. Cost? Who knows? Don't know if it has always been the case, but today they all cost the same. I'm at a loss... The most perplexing additional info is Zed Head bringing to light that they went back the projected tip with the P79/F54 combo in 1980. What made them want to pull that spark back towards the hole from 1975 through 1979?

Warning... Thread detour: So you took an early steering column completely apart? I've got one in that exact same state sitting on the bench right now... Did you take the bearings out, or did you stop where you took that pic?

It appears that Datsun switched plugs from the projected tip BP6ES (where the "P" means "Projected Tip") to the standard non-projected tipped B6ES (no "P") in 75? But what's interesting is that the small amount of armchair research I've done seems to indicate that the farther down into the cylinder you get the spark, the better the burn, and projected tips help in that way. Anyone know WHY they switched to the standard non-projected tips? Any reason I should not use the older projected tip BP6ES plugs in my 77? Here's why I ask... I've got projected tips in there now from my previous owner and they looked perfectly normal to me (after looking at 260 plugs for so long). They aren't hitting anything. They aren't burning up or showing any signs of overheating. They appear to be just fine and are loving life. So... If I've got the room for them, and the current projected tips aren't indicating any problems whatsoever, then is there really any reason I should switch back to the recommended non-projected tips? Maybe I should take advantage of the potentially better burn and stay with the projected tips even though it's not what Datsun recommends? What's the downside?

And.... I've been digressing into the comparison of the 72 and 73 and haven't even yet commented on your car in general... Congrats! It's a beauty!!

That makes much more sense for the new purchase to be a 72. And with that in mind, it looks pretty original to me too. There has already been some simplifying of the intake side already done though... When supplied new, you had: A PCV system. A throttle opener system. An evaporative emissions control system (flow guide operated). An air injection system (the air pump system). An anti-backfire valve system. An intake manifold and carb heating system. Of those, it looks like everything is intact with the exception of most of the air pump system and your anti-backfire valve (which is incorporated into the air pump plumbing). The only thing remaining from the air pump system is the air galley leading into your exhaust manifold and the check valve (that goes nowhere stub of tube pointing at your front carb). All of this may sound complicated, but just wait... Here's what the 73 looked like new. Complete with flat tops in all thier glory : In addition to all the stuff you got in 72, you also get an EGR system, a thermostatic air cleaner, an more complicated throttle opener system, a much more complicated carb and intake manifold heating system, separate idle circuit plumbing, etc! So if you're comparing your current 72 to your prior 73 and the 73 was simpler, then there must have been some serious work done to that 73!