Zed Head

If you run a hose from the exit of the FPR in to a can and still get high pressure then the FPR itself is a likely cause. The FPR is just a pressure relief valve. When pressure rises to its setpoint it lets fuel exit and go back to the tank.

If you want to narrow things down further, disconnect the FPR at its exit. That is a likely spot for misalignment. Since the FPR has two entry points it seems most likely that the single exit is clogged than both entrances.

There are two chambers in the master cylinder, on the same piston. Sounds like you might have blown one seal. Since the pedal moves far it should be pushing a lot of fluid. Somebody helped me solve a bleeder screw problem once when they noticed how much fluid was leaving and reentering the reservoirs. Have somebody watch the reservoirs while you press the pedal. If a lot of fluid moves there's air in the system. If very little fluid moves you probably need a new MC. You can have a bad seal inside but no fluid will leak out.

Make sure that bleeder screws are at the top where the air bubbles are. You can see the little channel for the screw. The end of the channel has to be where the bubble lives.

My mistake, I got my photos and figures mixed up. You really have to spend some time staring at those to extract mustache bar position. They are wrong though. Good luck.

I think that I got my 1978 FSM from xenonzcar.com, or nicoclub.com. Can't remember. I don't even see what you guys are talking about. I have Fig. RA-27 on page RA-10, and page RA-9 above it. No RA-276 or-278. Maybe somebody blended chapters to create a full FSM? Old with new...

Since you replaced some hoses you should move the gauge back to right in front of the rail and measure there. You're narrowing things down. Zero pressure on the return line might be good. seems like you would have seen a pound or two. If you still get high pressure from right in front of the rail, then the blockage is in the rail, or the FPR, or the line to the FPR, or the return line between the FPR and where you have the gauge now.

Are you using the Nissan/Datsun Factory Service Manual. Or somebody else's "FSM". It's in the 1978 Rear Axle chapter. Just chiming in. FSM = Datsun Service Manual.

https://forums.hybridz.org/topic/62691-l6-heads-pics-and-descriptions/

Should be letters and numbers cast in to the head up by the 1 and 2 plug holes.

We can all only guess, but one possibility is that since the requirements are exactly known and cannot be exceeded, it's safer to set a mid-range torque value to reduce the possibility of damage. The springs of the pressure plate are the limiting factor for force on the bolt heads. Plus, the bolts have leverage since they're out on the perimeter of the plate so don't see as much force as they might in a different application. Just a guess. I've never heard of anyone having a pressure plate come loose. I wouldn't exceed the spec. Imagine your aggravation if you strip a thread or break a bolt trying to be safer.

These adsense ads have to be related to conedodger. They only show up on CZCC.

Then sell it all on Craigslist ten years later...

That was my point in post #2456. Your Haltech might have its own "igniters". If it does you don't need an extra one on the coil. You might be redundancing. Many ways to get it done. The manufacturers' reasons for doing things are usually focused on ease of manufacturing and packaging parts. You could probably cut the ends off of the coils you have and make them smaller. That long tube probably just has a wire inside with a clip on the end. It's a solid plug wire.

I don't know if you call this bendy thing a wire, but it's what one guy does. Blake Machine. http://www.blakemachine.com/performance_parts_by_blake_machine/datsun_coil_on_plug_brackets_6__4_cylinder

Some of the COP coils have their own dwell control, I believe. I think it makes the head bigger. There's a bunch of COP options out there. Some smaller motorcycle COP coils might be less bulky. Just getting vicarious. https://www.ebay.com/itm/09-12-KAWASAKI-NINJA-ZX6R-ZX600R-OEM-IGNITION-COILS-COIL-SPARK-PLUG-CAPS/153137994597?epid=18017017407&hash=item23a7bc5b65:g:-6sAAOSwZthbZzSc

Alrighty. If you form some small divots in the bracket you can use it to hold nuts and bolts when working in there. Less slabby. Actually, some well-placed bends will make it more rigid. Carry on...

But with the bracket you can't see the full COP. Why not just use the coolant line bolt holes for the full mount? You could build a rigid mount, thin so that the COPs are visible and use the coolant line bracket holes to lock it in solid to the block. More stuff is visible. With a big bracket you're covering up a lot of good stuff. Just ideas. My engine bay is a pilot plant.

I was asking more about convenience. Seems like a lot of extra effort just to pop the valve cover. Is removing the COPS really that easy? Don't they clip on to the top of the plug like a spark plug boot? I struggle with a single boot. Easier than a ZX with its cooling fan though.

Re the COP bracket - will you be able to remove the valve cover without stressing the COP's or plugs?

Yes. I would. Many reman parts are poorly assembled. The parts might be new but the people putting them together are probably in a hurry. I would check and adjust the new one as if you had a problem and are running through a check list. Measure pickup coil resistance, make sure the vacuum diaphragm isn't blown, rotate the breaker plate, etc.

I've never adjusted a tach. I do remember trying to turn some of the screws in the back of a tach and they wouldn't budge. I would try putting the stock coil back on. That 0.6 ohm coil might be affecting the tach. I don't really know what the tach "sees", if it's a flyback thing or a low-high voltage thing. But I do know that ignition system modifications can affect the tach operation. Plus the 0.6 ohm coil is letting more current through your 40 year old ignition module. Not going to add to its probably short life remaining.

Don't worry about the 2-3 psi change. That is actually good, the engine is running better now and pulling more vacuum. The higher intake vacuum drops the fuel pressure in the rail because the intake manifold is pulling fuel out. It's working like it should.

You have to isolate the problem first I think. Can't say what you need. With the 280Z EFI cars everything needs to be right. Fuel pressure is one of the most important things to have correct with EFI.

Not injectors. They are not in the fuel path, they are on separate branches. The fuel passes by them. It would have to be in the FPR or one of the hoses in the fuel path.