Zed Head

Is the engine fully warmed up before taking off for the drive? The auxiliary air valve holds idle speed up until the engine warms up completely . Sounds like he's taking off with the engine cold and the basic idle setting is too low. Turn the big screw on the throttle body to raise idle speed. You can do it by hand. And the thing with the game piece on it is what keeps the throttle from slamming shut. If that's been deleted that might cause a problem. It's not a vacuum nipple, it just looks like one.

The picture you showed seems to be a flasher for the turn signals. There are some good diagrams in the Downloads area that might help you. I don't think that the flashers have polarity, the current just passes through and gets turned off and back on as the bimetal strip heats and cools. Here's one by EuroDat for the 71 240Z, and the general Downloads area link for more possibilities, like the Owners Manual. Find the flasher and see if the wire colors match. Good luck. Car looks very nice, is your grandfather still around to see it? Mine is long gone but I still have good memories. Learned that the sight glass on the AC line on his truck was not meant to be pushed. SSSSssstt.... https://www.classiczcars.com/files/file/79-wiringdiagramdatsun240z-1971-early/ https://www.classiczcars.com/files/

If you put your info in your signature people won't have to ask. Don't forget to save. https://www.classiczcars.com/settings/signature/ So, what are you working on?

280Z's with catalytic converters have a Floor Temp lamp. It lights when the converter gets too hot. Does your 75 have a lamp that says Catalyst? Haven't heard of that. The Hazard switch is known to have problems. You might search the site for past posts about it. Cleaning the internal contacts might be needed.

Classic Z-car question or classic maintenance question?

I'd measure battery voltage first. Not clear what you're starting with, maybe the battery has just run down. Also/or, is this with engine off or engine running?

Besides the length, won't you get dinged at the car show for hack saw marks? I like a smooth nut and bolt engagement and those marks make me squeamish. I can almost feel the rough edges through my eyes. CO has a future as a car show judge, I think.

Might be able to get factree. Looks like there was a change along the way. #25? https://www.carpartsmanual.com/datsun/Z-1969-1978/axle/front-suspension https://www.nissanpartsoverstock.com/p/Nissan__/Bolt-Hex-M10X125/89441985/08124-04510.html

My father refused to get with the CD craze for quite a while because the digital format didn't capture all of the sound, like vinyl or tape. It was a topic back then for the audiophiles. He gave in eventually.

I think that it will fit the car. There's room for a rearward-placed sump. But you'll need the pickup assembly from a 280ZX engine to fit the sump. Here's a good picture, from that 355 mile 280Z. Picture 358. https://bringatrailer.com/listing/1976-datsun-280z-39/

Knock knock...

But was he running old bushings? I'm suggesting that he replaced old worn bushings with new and it changed the geometry.

New bushings could have moved the wheel forward. As the bushings compress and shrink the suspension components move backward since braking is the dominant force. Control arm (transverse link) and T/C rod both. You might gain a mm or two back once you start driving it.

It might be that the missing return spring caused lower travel at the fork, but who knows. A smaller bore on the slave/operator cylinder will give more travel at the fork. I'd take a look at your pressure plate if you can and see if you have 1972 parts or newer parts. Looks like the master cylinder bore stayed the same but Nissan changed the slave cylinder bore over the years. Probably to match pressure plate changes. If you decide to get an aftermarket slave cylinder make sure you take it apart and clean it before installation. Some of use have found machining grit inside that will damage the seals.

What the hell is happening! My world makes no sense! We might have discovered the source of decades of clutch problems. New sizes.

It gets weirder. 1970. 5/8". 0.625". Matching master and operator.

Looking further I think that you asked a good question. I'd never really thought of it before, and even now assumed that you would just want to match the master and slave bore sizes, that they would be the same. But that is not the case, see specs below for 1976. Add on to that that the 240Z's had a taller pressure plate and maybe it is important to match the specs on all of those components. Pressure plate, master, and slave. Many people put later model pressure plates on their L24's. It deserves some study. Notice that image I pasted above has the 1976 style slave cylinder non-adjustable rod. Not the same! -

Actually, there is some weirdness out there. 3/4" does not equal 0.690". Not sure if the 3/4 molded in to the cylinder is its size or something else.

The seller didn't say, and nobody asked. Probably works just fine. He didn't get his price. He was hoping for 20, only bid up to $13,750.

11/16" = 0.6875 inches = 17.5 mm. I think that that's all that's out there. The self-adjusting slave cylinders have a spring inside. No need for the external spring. Nissan improved the system. Maybe a PO already used a newer cylinder. You'll need to swap rods like site said though, unless you change the clutch fork. https://www.rockauto.com/en/catalog/nissan,1971,240z,2.4l+l6,1209158,transmission-manual,clutch+slave+cylinder,2044 p.s. if you put your car info in the signature box and save it it will show up under each of your posts. It's under Account Settings. https://www.classiczcars.com/settings/signature/

Here's an interesting 75. Has had the EFI system swapped for a 1983 system. I wonder if it works well without an O2 sensor. Maybe @cgsheen1 knows. Looks like they did all of the parts, from AFM to ECU to ignition module/distributor. I'd comment on BAT but don't want to mess with the auction. https://bringatrailer.com/listing/1975-datsun-280z-66/

Automatics kill (value). $5,000 for a running, driving, passed-emissions-in-CA 280Z. https://bringatrailer.com/listing/1978-datsun-280z-193/

No reserve 240Z project with Stromberg carbs. Non-running for 20 years. Oak Harbor, Washington. @Terrapin Z https://bringatrailer.com/listing/1973-datsun-240z-313/

Loose mustache bar diff nuts is not an uncommon cause of a clunk.

I hate to say it but I don't think that you can trust most aftermarket parts today. Everybody is buying from Asia and they probably don't want to get tied to a specification. The primary spec. on the only part that had a spec. was huge. It was 1978 when Nissan created their 0.84 - 1.02 spec. About a 17% range. The Wells coil today, above, is 0.7 - 1.4. 50%. Not even close to the Nissan spec but they're selling it as a replacement. https://www.made-in-china.com/quality-china-product/ignition_coil-4.html Four E's VietnamFour E's VietnamDecade-long expertise in manufacturing premium Aftermarket Ignition Coils