Zed Head

Yes, but it's not clear what was done on this car. The lower port is not, apparently, blocked off. The big hose to the can seems to come from the lower block port. A person could argue "close enough", but, is it? The buyer can modify it, it's not a huge deal.

It has some odd mods. Check out the catch can plumbing. Looks like both crankcase vents run to the can. Can't tell if the system is actually open to atmosphere or plumbed to intake vacuum. Maybe there's a hose to the air filter box. And that's a lot of rubber fuel hose running over the top of the engine. Nissan used as much metal fuel tubing as they could, rubber hose was mostly short sections joining hard line. I watched some of the driving video and it's weird how these Youtube people become "authorities" on vehicles. Said that the Z's were considered to be poor handling, at about 8:14. Youtube is a very strange place. As is the internet in general.

You'll feel the teeth of the adjuster with the screwdriver. You'll be able to tell. A small thin screwdrive with a sharp edge is best. It has to grab the teeth as you push it inward. And, as noted, the access hole is at the bottom. The drawing that Nissan provides is good, just not well-explained. They're showing the screwdriver in action. They even show the direction of rotation. Jam it in, make the wheel turn until things get loose.

USA car in the UK. 1976. No reserve. Modified. https://bringatrailer.com/listing/1976-datsun-280z-117/

Check your distributor breaker plate. They tend to get rusted and stop advancing timing under vacuum. That will affect emissions. Might be able to break it free with some lubrication, but don't force it. The plastic bearing retainer tends to break. Disconnect the vacuum canister rod and move it by hand. Or remove the retaining screw for the canister and move the canister back and forth. Sometimes the diaphragm in the canister cracks and vacuum no longer moves it. Be gentle. I checked Rockauto for Champion plugs and that number does not show. Closest is RN11. There sure are a lot more plug types spec'ed these days than I remember. I think that manufacturers might just be saying "close enough" to make some sales. Nickels and dimes... https://www.rockauto.com/en/moreinfo.php?pk=205531&cc=1209260&pt=7212 https://www.rockauto.com/en/catalog/nissan,1978,280z,2.8l+l6,1209260,ignition,spark+plug,7212

What's the test procedure? Idle only or 2500 RPM under load? Does it have a catalytic converter? Since the system was designed to pass emissions I would set everything to factory specs. Ideally you'll be able to take it out for a good Italian tuneup or two before the test.

Since you're set to 3 bar maybe consider finding a factory OEM 3 bar regulator. 3 bar (43 psi) is common. I remember going through the search for an adjustable FPR, even buying an Aeromotive unit, but finding that the aftermarket units all leaked down rapidly. I eventually ended up with a late 70's Porsche style Bosch adjustable FPR that I modified to use a vacuum reference. It was fun. Anyway the OEM FPR designs just have a better seal than the aftermarket machined aluminum units and they're designed to last 100's of thousands of miles. Worth a consideration, I think.

Thanks for the pictures. I've never seen that. Was the engine running and it just snapped? Sounds like you already have the spare belt on. I would just assume it's a freak accident (not the six freaks in a van kind) and not worry about it.

Might be the regulator. They typically have very large seat area valves that can easily get jammed with a piece of debris. Are you sure the squealing is coming from the pump? The pressure must have been set before the test. Have you tried adjusting it while testing? The simple test of pump power is to squeeze the return line while the pump is running. If pressure does not rise it's the pump. If pressure does rise it's the regulator. If you find it's the regulator you might as well take it apart and look. There's really not much to them.

Your problem describes air leaking in, not fluid leaking out. One thing you might try, if you're actually seeing air released whenever you bleed it, is to bleed at the MC using the bleed ports there, intead of at the wheels. If you get air from the MC then you can refocus there.

Are you just assuming that your rebuilt MC can't be the problem? All of the other parts are factree except that one, if I read things right.

How about a picture or two?

Might want to get the right links too. White is not an option. Looks like someone cobbled up a DIY link.

Service manual says that auto and manual were both 3.54 in 1978. The difference is R180 versus R200. I was thinking about this the other day - I wasted money on getting my engine to run right because I didn't check injector flows. When I finally did I found that they were unbalanced, some flowing what looked like 10 - 20% less than others. If I was starting where you're at I'd do that and replace the injector seals. Vacuum leaks and low injector rates can cause misfires.

I remember those guys from way back when. Looks like we have a live session string going...

The next guy that needs a sensor will appreciate knowing if this one doesn't work. Do it for the next guy.

None of the pictures really show signs of what might have happened. If the sensor was too long it should have a mark on the end where it contacted the other side, and there should be a mark on the other side where it contacted. The lengths from the seating area look similar but hard to be sure. Might be that the new one just slipped past the seat, the tip hit the other side and it just pressed that threaded area right off. A caliper or another test fit would tell. Edit - Could also be that you got your wrench jammed against the plug in the adjacent hole and you sideloaded it. It is a nice clean fracture.

My first L28 leaked coolant from the head gasket seam at that back corner. And that hose fitting will come right out with a big wrench. Normal thread direction, righty-tighty. Use some pipe dope/sealant on the threads when you reinstall it. Rectorseal 5 is good, you can get it at most hardware stores. https://rectorseal.com/rectorseal-no-5-group/

At least they labeled them as special. You could retap to a normal size. https://www.carpartsmanual.com/datsun/Z-1969-1978/body-240z/seat-slide/type-2-reclining-seat/24

Seems like the whole cap could be CNC machined from a block of aluminum or polymer. Interested in the results. Good luck.

Can't really tell what you mean by shaving foam. Also not clear what you mean by alignment. Might be just me.

One of the flaws of the English alphabet characters - AI (Artificial Intelligence) looks like Al (Aluminum). Thought you made a typo. So, you're saying that now you can have metal parts fabricated in China and shipped to the US for a reasonable cost? Did you send them a file to work from? Is it printed or machined? Metal additive manufacturing? Interested in how it turns out. Found one - https://www.xometry.com/capabilities/3d-printing-service/metal/

I haven't done a conversion. Basically, take the plot and double the numbers on each axis for centrifugal advance. Don't forget that total advance under open throttle high RPM will be initial advance plus maximum centrifugal advance. Most people find that the best total advance setting is 34 degrees.

What material is AI?

123 has put together a tutorial. https://123ignitionusa.com/curve-tutorial/