Captain Obvious

A stock 73 is way more complicated and cluttered than what you have here. If this most recent purchase is a 73, then someone has made a lot of changes to the carbs and emissions controls. I took a look back through the thread, and I'm not sure you ever mentioned what year this car is... What is it?

I don't know if you would be able to actually smell a difference if your air pump is working or not. I do know that there are plenty of other reasons for a 260 to have a horrible exhaust smell. But as a data point... From my experience, a well tuned and proper operating 260 doesn't have a horrible exhaust smell, even without an air pump installed. As for the EGR tube, I'm not sure what you're talking about. The only tubes involved in the EGR that are soft enough to pinch are on the control side and pinching any of them could only result in the EGR becoming disabled (which usually improves performance, not degrades it). Spiders and chipmunks are better than floors and rocker panels with rust holes in them. To be honest? Dude, it's October. And you're in Connecticut. And this is your only car? You gotta do something quick.

Sorry TomoHawk, forgot to get back to you about how to control such devices. If I were to go to a solenoid valve, I would try to install a temperature switch into the thermostat housing. So I was thinking about it a little more, and what would be the real ticket would be to use an analog temp sensor (like the one that's already there), and use that analog sensor signal to control an air valve that is more complex than a simple ON-OFF solenoid valve. The air valve should be open when the sensor indicates cold, and closed when the sensor indicates warm, and partway when in-between. Kinda sounds like an idle air control valve, doesn't it? :bulb: Haha! Now vehicles have such devices incorporated directly into the throttle bodies!

Wait a minute... You're saying that this car is more complicated than a 73 you used to own? That doesn't make sense... The 73's had the first year of the flat-tops and all the associated complexity of the EGR and thermostatic air cleaner and CARB can, and and, and... This car you've pictured should be way simpler!

Thanks for that link. I remember breezing through that page a while ago, but I didn't read it closely enough to catch that line about a manual valve. I wouldn't be surprised of one of the older fuel injected Alfas used something like that. My old Alfa had a twist knob on the dash that would actually hold the throttle linkage down. It was a fine thread and you could turn it to raise the idle. Heck you could even turn it fifty times and use it as "cruise control" on the highway. :stupid: It was all mechanical and acted on the original carb linkage. In other words, the end result was the same, but they didn't put in a separate valve for the task. Instead of including a path around the throttle plate, they simply opened the throttle plate a little. Hmmm... All you need is a cable controlled valve that bypasses the throttle plate. I've got a couple leftover water control valves after my heater valve relocation project... :bulb: :laugh:

The 260 system is complicated. There are lots of tubes and wires and hoses and valves. It was the culmination of Datsun's efforts to provide good cold driveability, good fuel economy, and good performance all while meeting ever tightening emissions standards. That complexity works great when everything is perfect, but once it starts to fall off that razor's edge of performance, finding the problem(s) can be difficult. And that's where you are. You've got a forty year old car with unknown history. It's got dry rotted brittle tubing, solenoids that are probably frozen in place, sensors that might not work, valves that should be shut that are leaking, valves that should be open that are clogged, vacuum leaks, a dirty fuel tank, carbs that probably need a rebuild or more, and a questionable ignition system. Simply... The 260Z is not a car for the feint of heart. If you want it, you gotta want it bad. You have to be willing and capable enough to dive in yourself and learn how it works. Download a copy of the factory service manual and study it. Learn the terminology and where the components are. You've got to be able to point to something and call it by the same name that the manual calls it and have at least a basic understanding of what it's supposed to do. Without that level of knowledge and standardization of language, remote troubleshooting doesn't work. I know the 260 system pretty well, but I'm not close to you. If you bring the car to me and leave it with me for a month along with a stack of $100's, I'll fix it. If that doesn't work for you, then you need to find someone else closer to you, or learn to do it yourself. I'll do what I can from a distance, but diagnosing problems based on vague description is very difficult, especially when you've got so many places that could be causing problems. I'm not trying to scare you off. In fact, it's the opposite. I'm encouraging you to embrace ownership. Unless you're willing to pay for someone else to do it for you, you're going to have to learn a lot about the system yourself. My bottom line suggestion would be to buy something else to use as your daily and work on the Z in your heated garage in the meantime. If you drive the Z through the winter in CT, there isn't going to be much left.

Right you are, and good to bring that up so other people don't think that my car is "normal". What's missing on mine is the "thermal vacuum valve", and in addition to providing a "hot plate" for the AAR, it also enables/disables the EGR system based on water temperature. Mine was removed by a previous owner. I'm probably going to put mine back on, but it's lower priority at this point. I was worried that without the heat from the TVV that my AAR would never get hot enough to completely close, but that hasn't been the case. I've got my AAR adjusted to only provide a very small amount of additional air when cold, and it seems to generate enough heat with the internal heating coil to close even with the missing heat from the TVV. Of course, I haven't driven the car in any really cold months though. I might miss that TVV heat more in Feb than Oct. As for the issue of being always on, I (like you) am a little surprised that the AAR heating coils don't burn out more frequently. I believe the reason they don't burn often is that while the current is always present, it's pretty small. My AAR coil is around 60 Ohms, so at 13.6 V it draws less than 250 milliamps. And one more... I (also like you) thought about the possibility of ditching the AAR and using a solenoid valve(s) to control the auxiliary cold air around the throttle plate instead. My first stumbling block with this is that the solenoid valves are ON-OFF as opposed to the gradual "analog" closing of the AAR. I guess you could use a couple of solenoid valves in parallel and close them at different temperatures to simulate analog control, but that's more switches and more complexity. Not sure if it's worth it.

Sweet. Looking forward to it. So, the gauge I have works fine, and I know that because I used it for a while in my car until I swapped out my entire dash for one with "fewer" cracks. Now all I have to do is keep my mitts off it until you get here. Problem is you've got me all curious now!! So to quell my curiosity, I did a few minutes of armchair research and I believe the bi-metallic strip with the contacts (not the one that moves the needle, but the other one) is a temperature compensation device in addition to a voltage regulator. It pulse width modulates the current through the other strip in response to changes in ambient temperature and system voltage. http://home.roadrunner.com/~john.strenk/Gauge%20web%20page/WebPageGauges1.htm Remember though, I still haven't been inside one myself. And I promise to TRY to keep it that way until you get here!

Don't get me wrong. I'm not saying my 77 doesn't have the rollers... I'm just saying that I don't remember seeing them. I had my driver's side door panel off a little while ago and I just put it back on. I wasn't in there for window stuff so I wasn't specifically looking into it. I'm gonna pull the pass side next, and I'll definitely pay a little more attention while I'm in there on that side.

And another suggestion... I've got a spare 77 gauge that works fine, and you're welcome to have it if you want. Don't know if it's the same as what you're working on, but if it would help, just let me know!

The small hoses are 1/4 and 5/16. Between those two sizes you'll have all of the small stuff covered. The bigger stuff (the braided stuff) is more difficult. The hose on the top going to the valve cover is straight enough that you can easily find a replacement at the parts store. The problem is the braided stuff from the air cleaner to the carbs and between the two carbs. Of those, the one between the two carbs is the highest priority since it's at the highest vacuum and will such the most air if it has a leak. I'm thinking that you should visit that guy who knows the SU's.

I've never looked inside the gauges, so I'm shooting from the hip... Put a small capacitor across the arcing contacts to act as a snubber to prevent future arcing and use some gold leaf from the craft store burnished onto the contacts to provide a better contact?

You can add round top carb swap to your list of updates/replacements. A previous owner removed the original flat-top carbs in favor of the older round tops, swapped the original EGR balance tube for one from a previous year, and replaced all the carb linkages accordingly.

Are the 77/78 doors supposed to have that roller? I don't think I've got one (in my 77).

Mine was giving me trouble, so I carefully opened it up to clean it out and adjust. Then I drilled and tapped the casing for three small screws to hold the clamshell back together. Now I can disassemble and reassemble at will. Not supposed to come apart? Mine is! :laugh: Sorry for the crappy pics, but I didn't take it off the car just for a photo shoot. Two screws on top: And one on the bottom:

I wouldn't worry much about some oil in the valve cover hose. It's part of the PCV system and it's gonna happen. However, with that in mind, you should add checking/replacing your PCV valve to the maintenance suggestions provided earlier. Speaking of which... How much have you done with the car? Looked into any of the stuff mentioned earlier?

Yeah, I'm with E. I figure they felt they didn't need to show the tenths since the trip-O includes that. Just seemed funny to me that it was in there at all! Go through all that effort just to cover it up? The tenths digit does increment the 1's digit, and the assy (as designed) would not work without the tenths. Makes me think there were other vehicles that used the same assy that did show it. Something without a trip-O maybe? When I opened that thing up and saw six digits, my first thought was that there was a hidden 100K digit in there. And that would have been more than trivia. That would have been big news!! No more guessing how many times it rolled over! You know... With some modifications to the mounting tabs to make them a little wider, I bet I could add a 100K's digit to that thing... :bulb:

Not sure if this is common knowledge or not, but I learned something neat about the odometer today. You see five digits when you look at the odometer, but there are actually six digits available. There is a "tenths" digit on the odometer that is screened by the hole in the speedo face. Here's the front. There are five digits: And here's the guts. There are six digits, and the extra one is tenths: Who knew!?!

It looks great, and again... Thanks so much! As for the revision indicator, I think you misunderstood what I was suggesting. I was not suggesting a list of the changes that have occurred since inception. I was simply suggesting some indicator on the page as to what it's current revision is. Could be something as simple as "Revision H - Created 9/25/2012" in the legend area somewhere. Just so you can tell by looking at the picture itself when it was created or last modified. Just a time or date stamp, not history. Haha! I'd be happy to do what I can.

And... I just checked this, and the private messenger is correct. The original diagram from the 77 FSM has the magnet clutch connected to the blue wire and the BCDD cut connected to the white/black. It looks like a simple matter of mislabeled solenoids, because also in the original FSM, the A/C clutch is above the BCDD, and the BCDD is above the thermal transmitter. On your doc, the BCDD is above the A/C clutch. If you leave all the wiring alone and simply swap the labels between the BCDD and A/C clutch, everything will be correct.

There's no way I would ever blast a condesor with anything. Lightly or not. I'm no A/C expert, but since you didn't get any other responses...

Wayne, Thanks for the effort! Before this thing makes it to far though, there's something that doesn't look right to me. Seems the font style or weighting has changed between this version and your previous version. For example, take a look at the combination switch matrix and compare that area to the previous version. (Not E's version... that one has a different problem.) Your original one looks great, but the newest version has a font type that is so bold that it blurs one character into another. It's too bold, if that makes sense. There's a possibility that this is a user specific problem to me, so if it looks fine on your screen, then let me know and I'll send you a screen capture of what I'm talking about. Also, is there any reference on the document itself that indicates the change in revision? If not, I would recommend that. Doesn't have to be much, but something on the doc and not simply in the file name? Is that possible? Thanks again for all your help with this!!

Nobody? I'm the only one who has ever had such problem??? On a related note... I've got aluminum wheel cylinders. Does everyone else have the same, or are they steel?

Excellent. That's an even better solution! An HVAC guy with small hands. Another crisis averted!

Blue, Thanks for the help. I'm familiar with both styles of cylinders and what I'm working on are the 77-78 style with the two opposed pistons. I had the earlier single piston floating cylinder style in my 74. In the pic, you can only see one of the pistons, but I assure you... I've got two pistons and two seals per corner. The rebuilds I bought were Wagner 96618. I also got a box of parts from my previous owner that included some NOS brake parts, and in there were another set of Wagner kits (looked older than the ones I bought), and the Tru-Torque kits. I think I've got at least five rebuild kits, some unopened NOS still in sealed packaging and they are all the same... And none of them are correct for my cylinders. And like I mentioned above, I dismantled and stored a set of 77-78 cylinders from a parts car a while ago, and when things started getting confusing, I pulled that box off the shelf to see if it could add any info. The result is that the pair of cylinders in that box were identical to the ones on my car, including the pistons and seals with the larger hole in the center. Looking at the pics at Rock Auto, all the rebuilds they have appear to be the small hole style. Something seemingly this simple, and it's just not making sense?