Zed Head

Found a thread about a turbo ZX manifold. The ports seem to be right at the entrance of the runners. Seems like you should be able to see more in yours. https://www.zdriver.com/forums/280zx-s130-forums-77/my-turbo-plenum-32430/

Might be that those aren't access points for the EGR ports but are actually core plugs. Screw-in instead of the typical press-in. I've never examined the inside of an intake runner to see where the exhaust gases are let in. Might tell you something. There has to be holes somewhere. I've seen them on my 2003 vehicle, a Ford. They're known to clog. The FSM is pretty vague with magical arrows. Edit - actually I think that the holes are in the plenum not the runners, I think I knew that but had forgotten. Harder to see. Which I still had my pile of parts to go play with. A borescope view would be fun.

I found sandy material in mine also. I thought it might be carbon residue from exhaust gases, but maybe it's actually casting sand. Might be that Nissan found that it doesn't pass through to the intake runners so no need to clean it out. Who knows. Did you poke through to the runner? See if the port is visible.

I've removed one of those plugs. It's not too difficult. Heat the metal around the plug before putting the torque to it if it's stuck. Can't remember what I saw but I assume that the hole in to each runner is right below the plug. You could drill and tap each runner port and put a screw in it. Wouldn't be too hard to do. The alternative is more patching and welding or gobs of JB weld.

It might be in this thread or one of the others but I had posted some links about Mopar's fix for a similar problem with their Jeep engines. It was a foil heat shield for a certain injector. Apparently keeping the injector body itself cooler helped solve the problem. The L series engines are perfectly set up to overheat the injectors with their position right next to the bulky exhaust manifold.

I had a similar problem and found that installing a condenser/capacitor on the negative post of the coil made the tach work. I don't have the knowledge to put any math on it but my theory at the time was that the HEI module created more electrical noise, that affected the tachometer. But over the years I've found more about "kickback" or "flyback" from the coil field collapsing causing electronics problems. So maybe that's part of it. Whatever it is, the capacitor worked. It was just a common alternator radio noise suppression unit. Here's something from a Ford manual describing the kickback. Also an image of their "ignition transformer capacitor". It's one of those odd things that is there in print but very little words are used to describe how it actually functions. This system is controlled by the PCM, not an external module. Short story - a capacitor on the negative post might fix it.

Here's the link to the car. Looks like brakes have been addressed, including booster. You might think about double-checking the stuff that's been worked on, like the heads. Head bolts, valve lash, etc. Not clear how many miles were put on it after the work, or the quality of the work, or what shape the car was in in 2018. You never know. I don't recognize the name of the shop. Not criticizing, just saying better safe than sorry. And, inexpensive stuff that might be on last legs, like clutch master and slave cylinders are worth considering. Good luck, looks like a nice one. https://bringatrailer.com/listing/1971-datsun-240z-274/

Okay! Carry on...

Grab the top of the shaft and see if it has play. The reluctor wheel, the metal star that you're holding, has been known to contact the pickup coil if the bushing gets worn. There's stuff in the FSM about it. This one might be easier to do at the terminal where the red and green wires connect to the harness. But since 1978 has the plug it's actually pretty easy to do inside the car.

Rotate the engine, clockwise looking at it from the front to keep the timing chain tight, until the timing mark is at about 10 degrees. Remove the distributor cap. The leading edge of the rotor (it spins counterclockwise) should be pointing at the #1 electrode or the one opposite #1, depending on the stroke of the piston. So #1 or #6. If it's pointing anywhere else then you have a problem.

Just realized that I should have wrote "from" or after the headlight switch, not to. Otherwise it would buzz whenever the door was open. Any wire that gets power only when the lights are on.

The diagram is way back at the end of the BE chapter. Here's 1976. Here's the description. It does the interior light too.

I think that I tapped the power wire to the headlight switch and ran a lead cut the wire to the buzzer power supply side, and replaced it with the new lead. When the door is closed there's no ground so no buzz, when it's open the buzzer gets current if the lights are left on. I drive all of my vehicles with the lights on in the daytime so it was useful.

So the basic problem at this time is that the engine does not increase RPM when the throttle is opened. Correct? Have you checked ignition timing? I had an car long ago with timing so retarded the engine would barely respond to throttle. Didn't know what I was doing. I had just learned the time-it-by-ear method, and found that it didn't really work well. Got things all screwed up. It was a carb'ed engine. You might also check your throttle position sensor. I don't know what happens if it gets stuck in the idle position. Maybe it doesn't use the AFM until it's off-idle. It's another at-the-ECU-connector test. In the book.

Could be a mouse house in the air inlet system. It happens. No air = no rev.

A video with good sound might help. When you press the gas pedal are you sure that throttle blade is actually opening? Are you working the throttle by hand with the hood open or just sitting inside pressing the pedal? If it was mine I'd have the black cover off of the AFM and be working the throttle by hand, to be sure that things were doing what they are supposed to do. Move the throttle blade, listen, watch the AFM vane counterweight. I would also check ignition timing. Retarded ignition timing can make an engine run like crap. Your AFM numbers don't look bad. I don't think that's the problem. I've had a few with numbers that were off and have a theory that it's the ratio that matters. Not sure, but 180/100 = 1.8. 205/114 = 1.79.

That's just one measurement of many. You need all of them. They're shown in the book. Since you got a high resistance the next step would be to measure the same at the AFM itself. The high resistance could be in the AFM or in the wiring harness and its connections.

No injector ports are shown. Is that bar meant to be a fuel rail? The nipples are confusing, with one in the middle and one on the end. Why would you want the injectors so far from the head? Is this just a thought experiment or are you really planning to build something?

Actually you did mention it. But it's not enough. Nissan produced a whole set of instructions for testing at the ECU connector. It tells you that the wiring to the AFM is intact. The 1980 guide covers everything back to 1975.

I still like this thought. It fits your problem. Get out the meter, crawl under that dash to get to those kick panel screws (one of them only needs to be loosened, not removed), and pop that ECU connector off. If the ECU doesn't see it it doesn't happen.

I converted mine to a "headlights on" warning buzzer.

Similar cars go low and high. This one did pretty well. https://bringatrailer.com/listing/1973-datsun-240z-246/

It's a clutch. Kind of a bummer but I'm not sure that you can get the parts anymore. I browsed around but didn't find anything. 240hoke might know if he's still around. Don't know if he was ever a member here. He was active on HybridZ. https://forums.hybridz.org/topic/52029-adding-clutches-to-the-clsd-r200/ https://hokeperformance.squarespace.com/vq240z-build https://www.facebook.com/hokeperformance/ Here's a Google search page that has some good stuff. Of course, a call to the local Nissan dealer might be worthwhile too. https://www.google.com/search?q=site%3Ahybridz.org+clutch+lsd+r200

It's probably a 1988-1989 turbo 300ZX diff. They're the unicorn diff for people looking for the easy LSD swap for their Z. The only long-nose R200 LSD diff in the states. 1990 went to the short-nose. This is from the 1989 PD FSM chapter.

Looks like the dimensions are the same, but the drain pet-ckok is in a different spot. Pulled out a 76 and an 82. https://www.rockauto.com/en/catalog/nissan,1976,280z,2.8l+l6,1209226,cooling+system,radiator,2172 https://www.rockauto.com/en/catalog/nissan,1982,280zx,2.8l+l6,1209350,cooling+system,radiator,2172 https://www.rockauto.com/en/moreinfo.php?pk=10332348&cc=1209226&pt=2172&jsn=384 https://www.rockauto.com/en/moreinfo.php?pk=10332540&cc=1209350&pt=2172&jsn=391