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https://www.ztherapy.com/technical_stuff/spotterguides/zcar/240spotter.htm The 72 intake was water warmed to help atomize the fuel faster when the engine was cold.

Not sure that I agree. Once the engine gets up to normal operating temps, the carb heating loop is closed (as in: inactive, does nothing, might as well not be there). Any emissions-related benefits would be restricted to start and warmup conditions, where the presence of the manual choke would overwhelm any contribution that carb heating might make toward reduced exhaust emissions. Remember, too, that the federal exhaust emissions standards (and related compliance testing) at the time were performed only at ~ room temperature ambient air conditions and with the engine up to operating temperature (i.e. choke off, main thermostat open). It was always my understanding that the carb heating circuit was introduced in an effort to inhibit drivability issues caused by carb icing. Not all carbureted engines suffer from this problem. As well, it apparently isn't specific to constant-vacuum carbs, nor to inline engines, nor to water-cooled engines. Nor to cold-weather operating conditions. It seems to occur only with certain combinations of engine, carburetor, and engine compartment layout and under certain air temperature/humidity/engine speed/throttle-opening conditions. Evidently, Nissan decided that it had heard enough reports of problems with early Z's to warrant spending the (not-inconsiderable) amount of money required to install the carb heating loop (complete with revised castings for the carb bodies and the thermostat housing). There's a useful discussion of the Z's carb heating system on Hybrid-Z, here. And if you use the search function here on the CZCC site, you'll discover that several discussions about the system have taken place over the years.

Yeah, I think I would recommend running a return line, but that (like a lot of other details) can wait. I just want it to idle correctly for now! Haha! I'm no regulator expert, but I'm not a big fan of dead-headed systems in carb applications. This non-expert would prefer a bypass regulator system with a return line.

I have very little doubt that things will be a whole lot better now, but after four pages, I just want to hear it from you to be sure!

If the blue wire is disconnected, the rest of the ignition module is just along for the ride. It'll still be reading the input signal and switching it's output stage, but that output stage will not be connected to anything, so it will have no effect.

Well that vacuum connection you are using now is full manifold vacuum, but the system was designed to use a ported source that peaked advance at light cruise throttle (slightly above idle). With your direct manifold vacuum source, you will have peak advance at idle, and it will drop from there. I'm no timing expert, but I'm not sure that's what you want. And I don't think your vacuum connection is really a remnant of mixing and matching parts from different years. I think it's a remnant of snapping off the original ported vacuum nipple and then looking for some place else to connect that vacuum line. Either way... So when will we get an idle report to see if taking that nail out allows the front carb to operate properly?

Ohh I just did this, I would use Eurodats part list for OEM part numbers, or on the right side it has the bearing number (e.g. 6305 c3) and order high quality bearings from an online distributor. I bought a bk104 bearing from Transmission Parts Distributors it had one wrong size bearing, it gave me a larger bearing for the fs5w71c. All of the bearings in this kit were from Nachi, they were very smooth.

There are probably five major seals that would be best suited to Nissan OE if available: windshield, L/R doors, hatch glass, hatch inner. The principle suppliers of repro seals are Precision Replacment Products (PRP) and Vintage Rubber. The MSA kit is likely composed of PRP items. I heard some brief mentions some time ago the VR was actually using some pieces from PRP but I cannot confirm the accuracy of that. PRP door and hatch inner seals have long had a reputation for being fat leading to difficulty closing the doors and hatch. Most of the PRP seals for other areas can be used with good results. Don't overlook Banzai Motorworks and 240ZRubberParts for alternate sources of high quality repro items. Just my $0.05 worth - if that much! 😉 I'm sure others on this forum can chime in with experiences with both PRP and VR items. https://www.prp.com/ https://vintagerubber.com/ http://www.zzxdatsun.com/ https://www.240zrubberparts.com/

Nissan's S20 engine was nothing to do with Yamaha. It had Prince lineage. The Fairlady Z 432 was a Nissan. There was no 'Datsun Fairlady 432'.

I briefly owned a JDM 2.0L 70 Fairlady in college (around '95) that I traded a Marine a motorcycle for. I really loved it, but it ended up being beyond my abilities in terms of rust and foolishly let it go to the scrapyard - triple carbs, magnesium wheels, and everything. I've lost many nights' sleep over that tragedy since then - particularly since I ended up in a restoration career - so when I decided to call it quits with other folks' cars, I bought myself the most rust-free '72 Z I could find - to make amends for my past sins, I suppose. 🙂 I'm glad I stumbled upon this forum - I'm already learning tons of history and historical details, going very much down the rabbit hole, and will have MANY questions about my 240 as I touch up and renew some things that age has gotten the better of. So, thanks in advance! I'll grab some photos of it tomorrow at the shop for posterity and to start this off properly. Stay tuned.

Welcome and very nice score on the car!

Which would promote better and more complete combustion of the air/fuel mixture, resulting in lower exhaust emissions. Once the engine is at operating temperature, the thermostatic valve closes and blocks the flow of coolant through the manifolds. At that point the engine is warm enough to more completely consume the incoming fuel.

Yes, the carbs were rebuilt by ZTherapy back in 2011. I tried the carb cleaner misting trick, but it didn't seem to reveal anything (the idle was hunting so much I'm not sure I would have been able to tell anyway). Regardless, I got the intake all sealed up. New PCV valve, fresh balance tube gaskets: New steel exhaust manifold air injector plugs (w/high-temp thread sealant) to replace the ill-fitting brass ones I had in there previously. Also gave all the manifold bolts a retorque. I discovered some flakes in the rear carb line that must've gotten past the filter somehow, so I blew those out and checked the float and needle just to be sure. The engine seems much happier now. I sync'd the carbs and drove it around the neighborhood for a few minutes before it started raining. Idle seems steady and acceleration is smooth. I think it was a combination of a vacuum leak and potentially gunk in the carb line. Going to keep testing. Interior is coming together, though it's still got a long way to go. The steering wheel and handbrake handle need to be refinished obviously, and the radio isn't installed, but I wanted to get it put together "all up" before I have to pull the dash again to install the new heater control valve and the blower motor.

It's in the right way. It wont fit the other way. The other end where the selector rod passes through colides with 3rd and 4th when you fit the fork on backwards. If you feel comfortable wiring the forks it shouldn't do any harm. I take it you want to wire them because you're worried they might fall out or work their way out. They shouln't fall out that easy. I have only ever seen two 71B with them double pinned like @Zed Head said. One was for a rally car and the other was unknown.

The Chinese are a threat to the world in many ways. They are the leader in CO2 emissions, are an authoritarian government that keeps its foot on the neck of its people, steals intellectual property, undermines civil liberties and uses it power and influence to strong arm companies and governments. The least of our problems are the crappy stuff they make but I agree. Not sure why we (western democracies) do business with them. The only reason I can guess is that we value money more that our western values. It’s like feeding the neighbors dog steaks over the fence, when everyday it threatens to chew your face off. We deserve what we are getting !

Oh, and DadAndLadZ, forgot to mention.... Now that you have that nail pulled out and all the idle screws backed completely out, both carbs should be shutting tight-tight. And if that's the case, it probably won't even idle. You might find that you have to manually hold the throttle open a little bit or screw the idle screws back in some just to get it to run at all. Or you could pull the choke lever. As you saw, it should open the throttle plates a small amount. Pretty sure you would have figured that out, but just throwing that out there.

And for the folks thinking about flying to California for 2023, I can't remember where the host hotel will be, but I'm betting you'll be better off booking a flight to Ontario International Airport. If the hotel is toward Riverside/San Bernardino, you don't want to fly into LAX and drive across town.

I remember at school... teacher said: there are NO dumb questions, there are only dumb students that don't ask!

Oh, you should have said this in the beginning... You read what I said about the right turn signal pilot being tied to the right front turn signal lamp wiring? You have no idea if "your turn signals work" if you're only able to test the rear lights. I also said the turn signal lamps were on 2 separate circuits - one front, one rear. In this case it certainly can be an issue with the right turn signal SWITCH. That is as a very common problem.

Wow, good info, thanks! We will put it back together ASAP!

I rebuilt mine at home, I think I got a rebuild seal kit from rockauto. Works great… Clean up the calipers with purple power, throw on some paint if you want. Man I wish I had a media blaster at home. 😞 Power Brake exchange out of San Jose might be able to rebuild it, they rebuilt my brake booster, great service.

Yep, rubber seals are tough. I pretty much have everything in my restoration settled except the major rubber. On several occasions I have gone down rabbit holes trying to figure out which ones to buy. One post says Vintage another PRP then some suggest Kia rubber. I think I am going to wait until the last minute and order, that way I can send them back it they are junk. From my experience if Mike (Banzai Motorworks) sells it, then its top tier. I guess thats the reason he doesn't sell door seals :). What kind of 911's? I bought an 87 911 Cab M491 last year that had been sitting for over 15 years! My first Porsche, super fun car. Looks like you got a really nice 240, jealous looking at all that solid metal!

The ZCON 2023 website won't be live for a little while. Here's the Group Z website: https://groupz.com/

Look at the diagram and do what makes you feel comfortable. If the Crane module fails it will be easier to reconnect the old one.

managed to grab a correct radio for it (got lucky here, I think)

Nissan's East African Safari Rally 'Triple Crown' of overall wins usually refers to the consecutive wins of 1979, 1980 and 1981. Shekhar Mehta won all three driving Nissan PA10 Violets. The three cars now reside in the Nissan Heritage Collection at Zama. Nissan first won the event outright in 1970, with Edgar Herrmann and Hans Schuller driving a PA510 Bluebird. Herrmann and Schuller won again in 1971 in an HS30 Datsun 240Z. Nissan won again in 1973, with Shekhar Mehta driving an HLS30 Datsun 240Z, so the Z has won the event twice. Winning the Safari Rally was always a big deal for Nissan, and they celebrated their success with many stickers, posters, t-shirts and grille emblems. There are lots of repro stickers on the market these days, some of which take a little too much artistic license, some of which are plain absurd. There's a company making grille badges which takes this absurdity to extremes, mixing the 240Z/260Z/280Z with Martini stripes and the Targa Florio race. A bogus and bizarre combo: What?

E30 head - I did keep the JDM license plate and the emblems (really should have grabbed the mirrors and carbs too.)

When it's a "after market copy" product.. yes! (Please install original!) If you have a switch for 16 bucks i would not mess with the old one and put in a new.. unless this is a "as we said in the seventies" a jokytoky part (In that time meaning a bad, very bad japanese copy part.. now these days we mean a bad, very bad china part with that expression hahaha.. In the seventies the Japanese were doing what the chinese are doing now... only these days the chinese are much worse.. (Japan made also very good working copy's haha)

And can I just point out that when I said "I'm thinking that something within the carb itself is keeping that front throttle butterfly from closing completely"... I nailed it! HAHAHAHAHA!!!!!

Welcome aboard. That's a rare find. You chose wisely.

I guess this is an easy way to start: seller's photos

That makes sense. What I've never understood is the reasoning behind heating the carbs.

fyi, i had a reverse switch that did not work, turned out i had installed a copper washer during the rebuild that was not there before. remove the washer, bingo switch works. Agree 100% on testing things before throwing new parts, and when a new part is deemed needed, test it before installing...

My 10/1971 240z has the stock Assy-Thermo Manifold part # 14100-E8850 which I think is basically a thermostat that remains open until around 150 degrees then shuts off the coolant through the carbs.

I've never understood the reasoning behind heating the carbs unless it was to keep them from icing up in cold temperatures like my 521 used to do. The fuel is already pre-heated in a Z thanks to the routing of the fuel lines to the carbs.

Ive asked myself the same question long ago.. But apparantly it's better to have some heat in the carbs.. it makes the fuel evaporate better? There is a short loop through the engine and intake (and inside radiator in your car) at first, and later on when the engine gets warmer the thermostat opens to cool via the big radiator in front of the car. I have heard that in warm/hot country's they do not use the carb heating lines.. They leave them off as they don't do much..