Cooper260z

The soft brake lines I also replaced. I replaced with new rubber lines because I didn’t have the budget for stainless at the time and to the best of my knowledge they’re bled properly, brake fluid comes out clean. And I’ve adjusted the push rod, that was another step that got to my current scenario. @Terrapin Z I’ve heard about that disc in the booster before, how would I check for that?

@Terrapin Z thank you, I hadn’t heard of that before. But I just checked and both bleed screws are on the top, so that’s not it.

I’ve done some looking but haven’t found anyone describing this particular scenario. My car is an early 74 260z, I replaced the rotors, pads, rebuilt the calipers, new drums, shoes and hardware as well as new wheel cylinders and master cylinder. The brakes work pretty well though they don’t lock up the wheels but they don’t have very many miles on them so I don’t expect them to yet. The brakes work but the issue is that the pedal has nearly no resistance when depressing it while the car is running, it just goes to the floor. The braking force increases the further the pedal travels, the pedal just doesn’t get harder to press like you’d expect. The only thing that I can think of is maybe I don’t have the correct master cylinder? I bought it off rock auto rather then a Datsun oriented site. The front fluid reservoir feeds the rear brakes and the rear reservoir feeds the front and the master cylinder has “⅞” cast into it. So maybe it’s the wrong size? The car is very drivable as is but isn’t very confidence inspiring like I’d prefer it to be when it eventually hits the backroads. Thanks in advance!

For anyone in the future, I bought the wheels and they clear just fine!

I’m looking at buying a set of hayashi racing wheels, the specs are 15x7 +4 with 205/50 tires. Maybe someone has experience with this spec and could tell me if they will fit without spacers. The suspension on the car is all stock currently, so the top of the fender isn’t a worry, just if they’ll rub on the struts or something like that. Thanks!

don’t worry about it @AK260 in a way this is pretty directly related to what I was asking (or at least to the reason why I was asking the question) so it’s all worked out

Yeah, what zedhead said. Looks simple enough that even I could make it and looks effective. I’ll probably try to make one sometime, I like the idea of replacing the strap with a mount like that. But now is not the time for that, for me. however, now is the right time for me to try out cheap diagnosis! So I’ll give this a shot!

i like the RT mount but if I was going to make my own then I’d go with the nylon strap, which I never came across in my previous google searches. Too bad he never got around to sharing the length of the strap that he made. And I wonder how difficult it is to remove the old strap and install a new one without dropping the diff. Clearly it’s doable, though.

Currently the car has a fair amount of noise from the rear end when driving, most notably but not limited to when starting from a stop. Since I have these bushings I was thinking of seeing if that would fix the rear end noise since I don’t have the budget to replace the diff mount and strap yet. That diff strap alternative (if I’m understanding it correctly) is pretty interesting. I’ll keep that in mind when I’m ready to replace those, thank you

Quick question. I have a mustache bar that I believe to be for an r200. My car doesn’t have an r200, i have no need for this bar at this time, but I do want the new bushings that this bar has and I’m pretty sure that their the two piece style so they should be able to be pulled out. So the question is, is the diameter of the bushing slot the same as the bar in my stock 260z? (r180) I think they’re the same, I’d just like to confirm before I take the rear end apart (again) that I will be able to put these bushings in the 260z mustache bar.

if I can get a hold of the 240z linkage then I’ll use that balance tube, but I do have the 240z throttle opener if it would make a difference but at face value they seem the same. I feel like a bit of a bother at this point but do you know the correct way to attach the throttle opener linkage? The only way I see to attach it leaves that adjustment screw linkage piece suspended independently. Or are you saying that there isn’t really a way to do it because of my amalgamation of parts going on here?

Thank you @Mark Maras I will after I plug the air injection inlet so that I can concentrate on something other then the large exhaust leak in front of me. And while I wait on that, I’m looking at the linkage to this diaphragm. (That wasn’t meant to sound snarky or rude, if it did I apologize) So, I got the linkage from the l24 which I now see is significantly longer. Is this the proper configuration? Suspending the adjustment screw on the front carburetor?

Alright, so this piece of linkage that connects to this bar is what was keeping the linkage from returning all the way. I’m not sure what this mechanism is for yet but clearly these linkages aren’t completely compatible with each other. Also I’m not sure exactly what order these flats are supposed to go in, maybe that’s my issue. But disconnecting that linkage fixed it! So I guess the reason that it was idling at sich high rpm was simply because the throttle was being held open... who woulda guessed. So with that detached the car will idle and be responsive so I can try to dial the carbs in and fix some other issues I can already see!

Yes the second vacuum port on the manifold broke, I tried filling the hole with epoxy to seal it but that’s where we’ve found a vacuum leak when spraying brake clean in the area. I noticed that the linkage isn’t going all the way “home” I’ll say, and isn’t lining up with the service idle adjustment screw but I haven’t figured out why yet. I hadn’t noticed that connection but being bent before, it does look a bit tweaked, I’ll check that out. But this is the correct (I’m pretty sure) linkage for a 240z. With the flat tops the car did run quite well. I just noticed a few hiccups that I decided we’re likely carburetor based which is part of the reason why I was making the switch. So yes, using how the engine ran with the flat tops as a baseline, it should idle and drive fine. Maybe the tweaked throttle linkage is the main issue, I suppose that could explain the high idle but not the sudden idle jump and climb I don’t think. Also doesn’t explain the extremely low idle I don’t think

The carbs are on and most things are hooked up but I’m having a pretty sizable issue. The car will only run at 2000/4000 rpm and 200 rpm... nowhere in between When it’s running between 2-4000 it runs well and throttle response is crisp. When it runs at 200 rpm, the throttle mostly just chokes the system. Also the engine will seemingly just randomly shoot up from 200 to 2000 rpm. These carbs could be bad and in need of a proper rebuild, that’s entirely possible, but I really don’t much about the SUs so I’m not sure and I dont have the budget for the rebuild right now so I’m seeing if this problem can be fixed. Here is what I’ve done in an attempt to fix the issue as well as notes on the situation: I’ve moved the mixture nuts around and that seems to be a good way to get it to idle at 2000+ (turning the nut to richen the mix) but it can also jump to high rpm when the nuts are only around three turn out. The choke cables are currently disconnected because I found that I need a piece to affix the cable to these carbs, but I can manually manipulate the choke to get it to idle a bit better but still not great. The pistons in the carbs move up and down as I’ve read they should, with the 20wt oil they’re a bit harder to push up and slowly fall back to the bottom. One of the needles was a bit bent but I was able to straighten a bit by using the technique in the ztherapy video. I do have at least one confirmed vacuum leak and am not ruling out that I could have more. I’m guessing the sudden jump in rpm is one or both pistons rapidly going up? Im also getting a lot of backfires out of the carbs when it’s running at low rpm And here’s a picture of what the engine bay currently looks like, still very much a work in progress I know things aren’t prefect but please point out anything that could be an immediate issue Im actively researching trying to find information on a situation like this but I figure while I search might as well see if anyone can help me out. Thanks again to everyone that’s helped so far!

okay, I’ll keep that in mind if I have issues with the car running well. And thanks for looking @Captain Obvious I appreciate it! I do just want to get the car running decently well right now so I can drive it. Later I plan to do triples or maybe fuel injection and I’m not even sure how long this engine will last (Has low compression in a couple cylinders) so I don’t want to invest too much into it at this stage. wow! Okay @7tooZ will do, thanks!

I think the one that’s bent isn’t the one that had the stuck nozzle. It doesn’t look that bad (to my inexperienced and hopeful eye) and everything moves quite nicely now. I mean, I assume the options are get another needle or use it and have it wear faster, requiring a new needle? In wich case, might as well use it, right? For the mean time.

Thank you @Patcon I reassembled/reset the needle and all that per someone else’s instructions that I found on a forum and everything moves nicely now. Though one of the needles when looking through the bottom of the nozzle passage, the tip is biased to on side a bit. So I guess it’s a bit bent? But everything moves nicely. Is it a thing to worry about? Can I straighten it? Do I need to buy a new one? Thanks for all the help by the way, guys! Super appreciate it all!

The carb without the bar returns the nozzle flawlessly. The one with it that had the previously stuck nozzle, doesn’t return the nozzle all the way. It’s still a bit sticky and needs some help returning all the way. I won’t try to install them until later probably, I’ll see if I can get it to return better before putting it on.

Yeah, looks like someone got a bit aggressive with some of these screws. Not sure what that was about

It just seems like the bar could break if they took too much bending back and forth to tube. But if it works, it works. I was able to get the nozzle free after taking it apart and playing with it for a bit. It was just gummed up and stuck. Im still missing one of those bars that pops the butterfly open but I think I’ll still install the carbs and see how they work. I’m hoping starting and warming the engine won’t be too hard only missing a one piece of the choke system as long as I help it a bit with the pedal

I got these carbs from a guy that said they ran great, and in fact said that he had a mechanic friend that used to work on his Z that really knew what he was doing... guess I’ll just play with them and see what I can get to happen before I either get different ones and have them rebuilt

How intuitive! I’m sure that system has never failed anyone...

The nozzle is still stuck after disconnecting the linkage. Something els I noticed is that I can twist the nozzle and the thumb screw (adjuster?) and the hex closest to the carb body will all twist. On the carb with the nozzle that moves, only the nozzle will twist, the thumb screw and hex stay where they are. If that makes any sense at all...

When I pull the choke lever, the throttle plate moves a little bit and it moves the linkage that goes to the nozzle but the nozzle doesn’t move. I can’t pull the nozzle out by hand either like I can with the other carb