Zed Head

Could be the AC belt idler pulley bearing. Remove the AC belt and run the engine and see if the noise goes away. The water pump and alternator belt will still put tension on the damper. You can run without that belt for while also to see if the noise comes from one of those two. Then run with just the AC belt on. Don't know why someone would suggest a damper problem first. That would be the last place I'd look.

You would get a stronger spark over the full RPM range with the right coil for the system. The ignition circuit is a set of parts designed to work together to give proper current flow. Each component has resistance. The lower resistance coil will charge faster and give stronger spark at high RPM, and you could also set your spark plug gaps at the 1979 spec. of 1.0 - 1.1 mm. Your C6R coil is limiting potential.

Double. Got re-directed to the full editor for some reason.

A tiny change in orientation at the fittings will affect how the pipes fit when you reinstall. A couple of degrees off, longitudinally or rotationally, at a flange can equal an inch or two at the other end of the pipe. You might consider drilling holes and using strap steel and screws while it's on the car to get a rigid assembly. It would be like a mechanical tack weld. You can fill the screw holes during welding. I had a factory down pipe that looked perfect, even during assembly, but was off just enough so that I couldn't tuck it up to hang it without getting a leak.

Many of the hoses came from the factory labeled with a letter on a small piece of tape. If you're lucky the piece of tape is still there. If you change a hose, move the label or put a new one on. The letters correspond to the diagram.

The three-way connector is just a typical Tee fitting. One line connected to the throttle body (ported vacuum, only active when the throttle is off-idle), the other line ran to your vacuum advance canister on the distributor and the last one ran to one of the nipples on the cap on the carbon canister. The one to the carbon canister was used to open the main vacuum line to the manifold that would clear the canister of adsorbed gasoline vapors on the carbon. The last line on the canister cap was connected the vapor tank (reservoir tank in the FSM) back above the gas tank. If it's not connected to the canister it might be hanging around spewing the occasional gas fume in to the engine bay.

beerman makes a good point. Everything is there to create a spark but the ignitor is not making and breaking the circuit. Re-read thread and it seems like your coil negative post is grounded all the time. You either have too many wires connected to the negative post or you have a short to ground on the wire to the negative post or the module is damaged. That would explain all of the symptoms, except maybe the spark when the key is turned on. I would focus on the wire to the negative post and any place that it goes. This link might help too - PerTronix Instruction Manuals

Several people over the years (me and, I think, Eurodat, from this forum) have determined that a stack height of ~92 mm from the flywheel surface to the surface the clutch forks ride on, will pretty much guarantee that the parts will work together. I've attached a picture to demonstrate. Measure to the tips of the diaphragm fingers and subtract to get the collar height you need. There are three or four different collars out there. Edit - I see that you've already taken the measurement in your first post. Do the math and hope you can find the right collar. Edit 2 - I re-read your post and realized that you didn't really ask a question. But, 92 mm is still good information. Anyway, good luck.

Good detective work. The power transistors are the two silver disc-shaped objects on the top though, your burned object might be a capacitor. Just a guess, someone that knows electronics would recognize the shape. The sealed can look fits capacitor. Someone else on this forum found a similar burned object. They were going to try a fix also, never heard what happened. I replaced the transistors on an ECU so fixing the ECU is possible, but my parts weren't over-heated, they just went bad internally.

More resistance will give more fuel. Most of the potentiometers available will give way more resistance than needed, enough to flood the engine out. The engine probably wouldn't even run if you had the knob turned to full rich. So whichever end of the rotation it's at now is going to be the lean end.

I might be wrong here, with the electrical terminology, but I think that it depends on which side of the potentiometer you are using as a rheostat. If you wire up one side, it will be clockwise, the other it will be counterclockwise. Only two of the three pins are used. So yours could be either way, if you didn't measure resistance before you installed, you'll just have to turn it and use your nose, or the seat of your pants. Actually, I see that it's referred to in the atlanticz.ca page that you linked, about 1/3 down. I don't think it's necessary to short two pins together as shown, but apparently it won't hurt anything.

Any chance the head had some warpage? Was it machined to flatness before building, or maybe at the high end of the warp limits and used as-is? I've never rebuilt an engine but I'm curious. I have a warped head in the garage and wonder how much is too much and what the effects are.

You said in Post #14 that you charged the battery, the lights came on, and the starter was clicking like mad. You can still do the voltage drop test at the battery posts. If you aren't even getting a glimmer from a light, then the voltage should drop to about zero when you turn the key, if you have a bad battery that won't push amps.

There are some diagnostics you could do to separate battery from connections. Put a voltmeter on the battery posts, not the ends of the cables but the posts themselves, then turn the key to Start. If it's a bad connection, you'll get the click and the lights dimming but very little voltage drop because very little current is flowing. If you get a big voltage drop directly from the posts, then you have a bad battery or a very high load (low resistance or partial short) somewhere else. Could be the starter, for example. You can also measure resistance from the post to the connector (wire end) and from one connector to another. It should be essentially zero. Any resistance will heat up when current flows, expand and get more resistive. A couple of really simple things you can do before you spend more money.

I think that you missed the point that John Coffey was making in Post #2. 240SX's didn't come with turbos or CLSD's. But 85 or 86 200SX's might have. Look for 85/86 200SX Turbo parts.

FastWoman wrote up a procedure for rebuilding the fan clutch. It's out there somewhere. Involves replacing the silicone fluid inside, apparently it gets gummed up and stops flowing correctly. Wouldn't be surprised if there was something on atlanticz.ca also, although I haven't checked.

If your lights came back and the the starter got back up to click level, I would go back to Post #2. Check the connection between the wire end and the clamp also, odds are you have aftermarket clamps on corroded wire ends.

That is the first verified account I've read of a chain actually jumping a tooth (or two). It gets proposed all the time but I've never seen it verified that it actually happened. Thanks for the story. You probably saved the owner the cost of new pistons from the slippage happening at high RPM. He owes you.

I use the tiny little port that supplies the AC reservoir (the white bottle on the passenger side). Removing the FPR hose will change your fuel pressure and your air/fuel mixture, changing the way the engine runs (richer). I wouldn't use that one.

I only suggested the head gasket because some of the signs fit, but the signs also fit some of the other suggestions, like a collapsing hose, along with an ignition problem, for example. Those pressure numbers sure don't look good though. You have so many cars, and you're building your own engines, so I'm sure you know how to get good test numbers. Since it's so new and has few miles, I wonder if re-torquing the head bolts could save it? Not likely, but a re-torque would tell you if any of the bolts were loose, before you removed them to work on the gasket. If you find loose bolts, at least you'll have a possibility for the cause.

Instead of obvious, scary might be more appropriate. Headgasket,maybe? New engine, cylinder misfire and overheating.

The coil, both sides, should always measure battery voltage with the key on. Voltage drop happens when current flows, when the volts are used to do work (resistance is work). The ballast resistor is designed to drop the voltage to the coil when the engine is running, but it's bypassed when the starter is used to counteract the voltage drop from the starter motor. If you're measuring 9 volts with just the key on you have a short somewhere, because no work should be happening, since the coil circuit should be open. When the engine is running, there is current flow through the coil as the circuit is closed and opened to create spark. In short, after my rambling, your ignitor might be bad, apparently the early ones do that, shorting the coil to ground all the time. If you disconnect it from the negative post of the coil, you'll probably see 12 volts at both sides.

Either your battery is dead or you have a big draw at the point that you're measuring voltage. With the key on, and the engine not running, you should measure battery voltage at the coil. Voltage won't drop unless current is flowing, which it should not be doing with the engine not running. Dead battery seems most likely here. What is its voltage, measured at the battery terminals?

So, on the fuel, it sounds like the filter was blocking gravity flow of fuel to the pump, and the pump was so dry it's rotors were just spinning in air. Interesting fix. You should still check pressure before messing with the AFM. Fuel pressure is the basis of fuel injection. You can waste tons of time if your fuel pressure is not right. There's a whole chapter specific to the automatic transmission in the FSM. It's the only chapter with color in the diagrams. Also has a very large trouble-shooting chart (not a good sign!) with "failure to shift 1st to 2nd" as one "trouble".

I don't know what the L28's use in "tasmaina" (OP's location) but big cams on a stock EFI system is bad, big cams on carbs is good. That's what I've learned anyway.