Zed Head

Have you checked the coolant temperature sensor circuit, at the ECU? Or even at the sensor itself. Make sure that it is connected firmly. It's in the thermostat housing. Sounds like it might be disconnected.

I don't think that you ever solved the first problem. You might have squirted enough fuel through the CSV and injectors to get it to start and run but there are still fundamental problems. Give some history of the car. How long have you had it, did it run when you bought it, etc? You didn't tell anything in your other thread. Could be it just has old gas in the tank.

Getting closer. "giving it gas" means holding the throttle pedal all the way down or pumping it up and down or pushing it part way down? Does it warm up and run right now, after you get it started? I kind of recall your past problems. You never came back and said that the problem was fixed. I said last time that the hissing was normal.

You're off on a wild goose chase. It's normal for the FPR to hiss and your fuel pressure is in the right range. You shouldn't have changed the FPR and you should probably put everything back together and leave it if your fuel pressure is about 36-37 psi. There's probably something else wrong. Give some more detail between when it last ran, and now. How long has it been sitting, how warm was it when it "ran perfectly", how long did it run perfectly, did you drive it, stuff like that. Might be that it ran perfect for 20 seconds then you shut it down for two months. Can't tell. Does it run long enough to warm up? Does it run well after it warms up? Lots of missing information.

Looks right to me. The timing chain sprocket probably just has some casting variation. It's obviously not a super-balanced precision machined part. Things look right. If you wanted to be very accurate you could build or buy a piston stop, and verify TDC. I built one from an old spark plug. On the other hand, if you're pretty pretty pretty sure that the piston is at the top and the damper notch is right, it might not be worth the effort. I'd take a good look at all of your cam lobes and rocker arms, wiggle them, check lash if you can. While you have the cover off. You might have seen Neb's cam lobes. It's well-known for the valves to be so sticky after an engine sits for a long time that they hang and a lash pad pops out. People find them laying in the oil puddles up there after a run up through the RPM.

Ironically, I've always thought that that's where the term "butt head" came from...

There is good information in that link. Sensitization is a subtle thing that can't really be predicted. I met a guy years ago who was part owner of a company that built high performance kit airplanes. He'd been working with two part epoxies for years and one day he started a job and found that he couldn't work with them any more. His body started acting up and he couldn't be around them at all. He had to stay out of the shop when they were laying up the materials. He still seemed kind of in shock just telling the story. So you might think that since you've been exposed in the past and nothing happened that you'll be fine to keep dong what you've been doing. But once your body changes it's "mind" you're done.

The groove, in the back plate, isn't really visible. Not sure why. Not the same as your first picture.

And other big institutions, like Facebook or Google. I think it's an ages old dream, that society will develop institutions to keep all of us safe. They always get corrupted though. When I posted that it was more as a reminder that bad things can happen. Things seem to cycle back and forth between too much trust and cynicism. I'm cynical so I've done okay, but many new people are on the too much side. A too-much-trust person seeing the name "Goof Off" isn't going to read the fine print that closely. The family should sue for misleading name. That's my cynical side, implying that the company was hiding the danger with a silly name. If I was on the jury I'd probably vote for damages.

I think that EuroChas implied that, not me. Neb is making fantastic progress, he'll probably come up with his own plan pretty quickly. Lots of options, from building an engine in the "meantime" to swapping heads, to swapping engines. Many of us have the parts for those options in our garage or sheds. I ponder those options occasionally then take the car out for a drive and decide that it's fine like it is. It can sit for a while and start when it's supposed to, and it doesn't break down. And it's fun to drive when I drive it. That's the goal I set when I started. I had my crazy days back with the GTO and Pontiac 400. Can't fault anyone who takes a different path.

Jalex, I think that people are just messing with you, for fun. Your mechanic, or you, is/are not being careful when he/you remove(s) the air filter cover. Banging it on the shock tower. I would cover the shock tower with tape until you get your problems solved. Or place a towel (orange or not) over the shock towers before you remove the covers. If your mechnic is dong the damge, tape, if it's you, the towel. Those painted strut insulator nuts look nice. You can see the edge of the other fender paint protector. You just need more protection.

Just saw this, and we were just talking about it. https://www.cbsnews.com/news/dangerous-paint-stripper-chemical-methylene-chloride-ban-on-hold/

That head kind of looks like somebody's past experiment, that they tried to run and didn't get quite right. There are many moving parts that have to work together. But, I think that I can dissuade you (been waiting to use that word...) from entertaining the thought of putting that head on your engine, unless you want to spend quite a bit more money and time on it. Look at the cam lobes. The rocker arms are probably similar. You might just have a collection of parts thrown together> The bluing on the valve seats looks unrun, but there's no reason to put that camshaft on a head you're going to use.

Not sure why you posted the same thing over again. It's your third posting. Insert an @zed2 and it will notify him. It worked this time. You're welcome for the link to all of the part numbers also. Good luck. 240Z and 280Z are not all the same.

@zed2. I'm locked out. You'll have to try it.

Here's one spot. http://www.carpartsmanual.com/datsun/Z-1969-1978 You can @ people that you want to notify. @zed2. It doesn't always work though. I think if you do an @ but don't add a name it locks you out from any more @'s.

What year is your car? The 240Z's changed over the years, electrically.

Here's a link that seems to cover everything including a way to possibly get the wrong number. Looks like 108 mm is the number. Norm the 12 Second Dude was deep in to L series engines until he crashed his Z and sold it. http://www.zcar.com/forum/10-70-83-tech-discussion-forum/123994-stock-head-thickness.html

There is a dimension for the thickness of the head that you can measure. From top edge to bottom edge. 4" plus a little more if I remember right. I'll see if I can find it but somebody here might have it on the top of their head. You might just measure yours and post it, and somebody can verify, or even measure a head to compare. I have one in the garage. They're all the same across the years because the same cam timing gear, chain and sprockets, is used on all of them.

It does not seem you've done much at all besides, probably, turned some switches. It's not even clear that the engine runs or even that there's a battery in the car, and it's connected. No offense. You're new and all we have is the few words that you wrote. They don't tell much. I wouldn't want to travel all the way to your place just to find out the seller disconnected the battery to save it from discharging.

@sweatybetty is down that way.

I would check the control arm bushings also. Seems to fit your symptoms. The FSM is available in the site's download section. The picture is from the RA chapter. http://www.classiczcars.com/files/category/14-280zx/

C'est what?

Edit - apparently it is valve head diameter that you measure. It's not what I would want to know but it's what is done, apparently. So your valves are close to L28 size. Actually, it's hard to tell from the out edge measurements, which overlap the seat. I think that the number is actually the seat diameter. Where the flow happens. 1.74 and 1.375 are 44.196 and 34.925, so more likely 42 and 33, stock E88. A guess. Not large enough to be L28 though. I could be wrong. I forgot about the injector cutouts, so that's a consideration. I'd just get what's in there running well, drive the crap out of it and see if needs more of anything.

I just like looking at nice cars for sale. And people get on this forum all the time asking if the car that they're looking at is worth the money. So, big picture wise, my questions will probably help you make a sale. You didn't say why one picture shows a rectangular side mirror and one shows circular. I have those circular mirrors on my car, bought from MSA. Just wondering. If I wasn't asking, it would just be a silver 1975 car with nice paint, nice wheels, and early bumpers, and a lot of unknowns, for a relatively high price. Good luck!