Captain Obvious

Excellent. Glad it was that simple. Nice that you didn't have to discharge the whole A/C system and pull the dash to fix it. Enjoy the warm toes.

Glad to (try to) help. I'm operating off obsolete brain cells with the details of the A/C stuff. Been a long time and I don't remember all the details. I do think disconnecting the linkage off the vacuum actuator is a good idea. Might be able to figure out if the problem is inside or outside the heater box. But be warned... there really isn't a lot inside the box. Unless some piece of foam has fallen out of place and is jamming up the works I'm not sure what else could have gone wrong in there. One thing I've seen in some other cars is that when the original foam degrades over time, sometimes it turns into a sticky gooey mess. I don't remember if that happens with old Datsun stuff, but if so, your mode door might just be "glued" into place by sticky residue left over from failed antique sealing foam. Also, here's some pics I took when I had my air box out of the car for some work. I don't have A/C, but the basic system parts (like the air box) are the same for all the cars. You've just got the vacuum stuff bolted onto yours that I don't have:

And BTW, aren't all the doors on the A/C cars tied together with the vacuum actuators? Are you sure your problem is with the mode door and not with the heat/defrost door down closer to your feet? The linkage for those floor heater doors is kinda kludgey.

The mode door is hidden behind your evaporator core, isn't it? If that's the case, you won't be able to do much from the front. You can get a little access to the mode door if you pull the blower assembly out of the passenger footwell. There just isn't much to it though... Pivots on two pegs on the bottom. I think I got some pics around here somewhere.... If you take the linkage off the drivers side peg, you should be able to move the door smooth through complete range of motion. Might tell you if it's a linkage issue or something inside the box. Maybe a critter dropped a couple nuts into your air intake and they came through the blower and are jamming the door?

You checked fuel delivery to the carbs, but did you verify that fuel is actually making it into the bowls? Maybe your little screens or your float needles have plugged up? I know it's unlikely that both carbs did the same thing at the same time and I also know you said that it wouldn't start even on starter fluid, but I just want to play too.

I agree. Unless you've already got a well done headlight relay install, you're gonna burn something up. And, in fact, if you don't already have headlight relays, you're not getting all you can out of your current bulbs. I took some measurements before and after my relay install and those measurements indicate that I'm getting almost twice as much power out of my bulbs now than I was before. (And I haven't looked into it, but I suspect the power in to lumens out relationship for incandescents is very non-linear...) Bottom line... Step one would be to make sure you're getting every possible lumen out of your current bulbs. Do you already have a well done headlight relay install?

Maybe your other locks have been changed out in the past and for some reason they didn't do the hatch lock? I've heard that the hatch locks are impossible to find. NOS is very rare and nobody makes a new replacement like they do for the doors and the ignition. One of the other locks on the car that goes unnoticed... the glove box lock. Does your current key work in the glove box lock? If it doesn't, then maybe the hatch and glove box use the same (older?) key. If your current key DOES work in the glove box, then I'd suspect there's something busted up in your hatch lock like a tumbler has split and is jamming up the works inside.

Haha!! Nice! I already get "up to" 10% ethanol at the pump, but I bet yours tastes a lot better!!!

And since we're talking about ported vacuum sources... Here's a pic down the throat of the throttle body and you can see the distributor advance port on the left and the EGR port(s) on the right. Been a while since I studied it, but IIRC, the pair of larger holes in the foreground are BCDD. The distributor port is the rectangular slotted one on the left back where the butterfly would contact the housing if it were closed (instead of being blocked open as it is in the pic):

Yeah, I took a quick look through the service manuals looking for some sort of diagram or sketch that did a good job of showing those vacuum lines and came up with nothing very good. Best I found was in the Engine Tune Up section, and the clearest year I found was 1977. So take a look at ET-2 in the 77 FSM manual. You're interested in tube numbers 5, 12, and 14. 14 comes off the throttle body and goes to a metal "T". 5 comes off the "T" and goes to the vacuum can. 12 comes off the "T" and goes to the distributor.

I've thankfully never needed to open up a Z transmission but I have been inside a couple other manual transmissions in the past and I assume the basic concepts are identical. Point is, I'm no expert and other than pointing out that it sounds more like a linkage or interlock problem than a clutch problem, I'm not the guy who can pinpoint the exact location of the issue. I did in the past work on a transmission where it was hard to get it into a non-synchronized (first) gear and it turned out that the two gears that meshed were both badly damage and the teeth had actually smeared to the point where getting them to mesh was difficult. On that one, there was a also a loud whine when in first gear. I don't think that's what is going on here.

It's the one that points toward the radiator. Vacuum from that front port should "T" to go to two places. 1) the distributor vacuum, and 2) the carbon canister control line.

Forgive me, but I'm not sure I can see how this could be a clutch issue. Because reverse is non-synchronized, clutch drag would manifest itself as a grind when trying to put the car into reverse (because the gear teeth would collide until the collisions were severe enough to stop the clutch disk from spinning). But since there's no grind, why is the clutch adjustment theory so prevalent? I'd be more suspicious of a linkage issue with one of the shift rods or maybe something to do with the interlock detent balls?

Very nice! No point deductions for you!

Seriously? You're worried about changing from Philips to Allen or torx on the horns because it might be "obvious"? Seriously? I know obvious (obviously) and that's not obvious. Haha! That said, if I ever, ever, ever see your car, that's one of the first things I'm going to check for. You better thank your lucky stars that I'm not a show judge.

I don't know about "most", but a lot of them do. Maybe 50/50? Problem (my opinion) is that a lot of them have recently standardized on a web site design and I don't like the new one. Here's a couple options near you. Note that they are all running the same website. They probably enter in their own percentage discount off stock and their shipping and handling charges, but other than those customizable parameters, they're all the same. Scott Clark in Charlotte - http://charlottenissanparts.com/?siteid=216961 East Charlotte in Charlotte - http://www.nissanpartstogo.com/?siteid=216616 Harrelson in Rock Hill - http://harrelsonnissansocarolinaparts.com/?siteid=216864 Thankfully Courtesy has not succored to the temptation to standardize. Hopefully they never will. There are fewer things I hate more than searching by VIN. Courtesy - http://www.courtesyparts.com/

One "trick" that I've used to help determine availability is to check at a couple other dealerships as well. If it shows up as a good part number at other dealerships, then you can be pretty sure that it's still a good number and Courtesy can get it. But if it shows up as an invalid part number elsewhere, you're about 50-50 as to whether Courtesy can get it or not. And one other tidbit... Recently I noticed that a bunch of the other (non-Courtesy) Nissan dealers had all standardized on a new format for their website. I told the guys at Courtesy that I didn't like the new format and they said they were updating theirs as well, but weren't doing what the other dealers had done. My feedback to them was "Good. And thanks for keeping a light on for the old Datsun stuff." Now this was all in the hanger at ZCON2015, so they were clearly there in support of the Nissan/Datsun. I told them that it's great that they are willing to put in the extra effort to work on the old low volume stuff and not hate doing it.

Interesting that parts availability came up... I spent some time at ZCON talking to the guys from Courtesy about that very topic. I've had a couple occasions where I've found parts on their website with a reasonable price, but when I inquired deeper, the parts were actually NLA. I was asking the Courtesy guys if there was any way to tell without them manually looking into it, and the answer was "no". So, unfortunately, even if it looks like a good part on their website, it might not be. They'll NLA them as the situation occurs, but until they look into it, they don't know and it looks like a good part.

Yes, they were tingling. Send me some pics when you get it together. I've already told the family that I may be coming to live with you for four years depending on the outcome of the next election. If that happens, I'll teach you everything I know. Then for the remaining three years and 364 days, we can drink Labatt's and watch Second City TV reruns.

It's not unbalanced much. I suspect you won't even notice. However... There may be some issues getting it chucked up successfully. Will depend on the size of the lathe. You need either a big one, or a little one. If the lathe is big enough, you can stick the angled portion through the hole in the spindle. And if the lathe is small enough, you can run the T/C rod all the way through the spindle from the non-business end (over where the drive gears are). But if the lathe is in the middle... You won't be able to push the angled end into the spindle (because the hole through the spindle won't be large enough) and the T/C rod may be too short to poke all the way through the spindle and still have enough working length sticking out the chuck because the headstock is too long. Kinda hard to describe without pictures... Haha!! Does any of that make sense at all? But in any event, as Chickenman mentioned, make sure you put a fillet on the base of the shoulder. Don't put a hard 90 degree corner in there. Can't possibly make that scary rusty T/C rod any worse! You've got the perfect practice piece.

Glad to hear that swapping the washers around gave you enough clearance to claim victory. Kinda surprised it made that much of a difference, but whatever works! Now that you got the immediate crisis under control, here's an idea for the future if you want more clearance. Chuck the T/C rod up in a lathe and remove material to shift the shoulder that the washers sit against closer to the control arm. You'd gain clearance at the expense of caster. Blue, You got your lathe up and running yet?

Weird. I wish I had some silver bullet solution, but I don't. As far as I can tell, the T/Cs were never changed throughout the whole run. Same part number from inception to end of model. If you've got the rear nut torqued down until you've compressed the bushings to the point where you're clamping on the inner sleeve, then I don't know what else to look for. What are the chances that your wheel/tire combo is just too large and you've been masking a potential rubbing issue all along with your adjustable setup? And I know it's ridiculous to even ask, but I got nothing else... When you attached the T/C rods to the control arms, you got both bolts installed, right? You didn't do something ridiculous like use one bolt through the front hole on the rod and the rear hole in the arm and get the whole arm pushed forward? I know, but I gotta ask.

Mario, I know you're on vacation, but if I don't write this stuff down, I'll forget. Two things to look into when you get a chance... 1) Not sure if you still have an EGR valve (or if has been removed). If you do still have one, it might be leaking when it should be closed. This would lean out your idle mixture. Actually it would lean out your mixture at all times, but like any other fixed size vacuum leak, it would have the greatest impact at low RPMs. 2) Have you verified that your ECU is getting the START signal? Pin 4 should go hot in START and that temporarily richens up the mixture some.

If there is truly a clear flood mode to the ECU It seems really odd that there would be no mention of it in any of the service manuals, owner's manuals, or the the FI guide. The ECU has access to the START signal and the WOT signal, so they COULD have put something like that in there. But if they did put that in, why didn't they tell anyone about it? Yeah, if you could post a copy of that TSB, that would be a great piece of FI trivia!

Yikes! Nice snake. That'll keep them acorn hording critters away for sure! I had a hard time getting the suction cup to stick, so I've used double backed sticky tape to the valve face. If I get a chance, I'll snap a pic of my valve lapping ummm.... "tool".