Zed Head

One thing not thought about often is that it takes torque to spin the alternator as it produces power. So that 120 amps needs a good tight proper belt to avoid slipping. It could be that simple.

The coil and ignition module put out an electrical pulse when the reluctor passes the magnet in the distributor, and it just follows the least resistance to ground, Shortest gaps to jump along the way. Where the rotor is pointed determines the shortest gap in the cap. Just basic stuff, follow it out and see what you find. Could be a defect in the cap or a stray piece of wire that got in there somehow. The cap is easy to pop off and inspect. The 280ZX distributor also uses the six pointed reluctor so you can't even have a bad tooth to screw things up. Since you don't see current flowing in the wire (no light), it must be at the cap. Could also be that your #5 wire isn't seated properly and the gap is too big to jump (not good for the ignition module, by the way). Reseat that wire and try again.

Take the belt off and see how the bearing feels. Check the water pump also. It has a bearing.

Wan't really clear. If it's only one wire, there's only three things to look at - the plug (losing ground for some weird reason), the wire (losing continuity), or the electrode in the cap. Above 2000 RPM, the rotor will be in a different position relative to the cap electrode as the mechanical advance turns. Could be that the spark is jumping to a carbon track in the cap and bypassing the #5 electrode. Losing one spark is an odd problem though. Are you sure you didn't just imagine it? Over-hope?

Doesn't really fit your acceleration weirdness, does it? No pickup from idle to 2000 RPM with six sparks, and awesome acceleration after 2000 with five? You're testing for spark with a timing light or tester of some kind?

If it is the same car, the nickels and dimes will flow for a longtime to get it in to decent shape. Every little trim piece is probably costly, especially for the 240Z's, and is hard to find. Could be a fun project but you probably won't be driving it much for quite a while. Doesn't the VIN plate look a little beat up? Makes you wonder.

Since "R" is after TDC, and A is before TDC, when the marks are as shown, timing should be at zero, not 5 degrees.

Looks in good shape. Two sources you'll want to at least open and browse through are linked below. Engine Fuel chapter in the first, and the second is a collection of tests covering many years, in the Guidebook. Get the 1980 book, it covers all. There aren't really many people out there "qualified" to work on these old EFI systems. If you know the basics of an engine and how to use a meter you might be best off to do your own work. http://www.nicoclub.com/FSM/280z/ http://www.xenons130.com/reference.html

This is probably the Ignitor kit that you have - http://www.summitracing.com/parts/pnx-1741 And these are the instructions - http://static.summitracing.com/global/images/instructions/pnx%20ignitor%20i%20tests.pdf which say that you want 3.0 to 4.5 ohms on your coil circuit. Resistance is added in series so just add the resistance of the coil to the resistance of the ballast and make sure that the sum is between 3.0 and 4.5 ohms. Since you have a 3.0 ohm coil you can remove the ballast and run the coil without it. You'll be at 3.0 ohms, which is in spec. and will give the hottest spark. That's what I would do.

Sorry, I got my years mixed up (again). Your engine has a cylinder head temperature sensor (CHTS), in place of the coolant temperature sensor used on the 280Z's. It's on the right side of the engine, above the spark plugs, between 5 and 6 I believe. Same style of connector, and you should fine the bullet connectors, I think. As site said, a vacuum leak after the AFM would cause a lean condition also. Easier to find and fix that, if that's the case. Even the PCV system, the hose underneath the intake or the one from the valve cover, can cause a lean condition if it leaks.

I've found several 76 and 77 distributors with 11 stamped on the slotted portion (the cam, I assume it's called). Not sure the FSM is 100% on what actually came in the cars. Assuming the stamped numbers are the maximum centrifugal advance. Has anyone ever determined what the typical CARDONE rebuild distributor has? They show the same distributor as compatible with many years. They must have chosen some middle ground.

I thought the tuned circuit part was for points, along with suppressing the arcing to make the points last longer. Not sure that the same applies to transistor ignition systems. Arne's problem was with a Pertronix electronic setup and it was never really clear why his had problems but numerous other people with the same setup didn't.

Click a few times. It's called "Fuel Tweaker". Radio Shack restructured, but didn't liquidate. Dallas is probably big enough to support one. How's that for "dead"?

Is that Buddy Holly's garage?

Describe the rest of the ignition system. Do you have the Pertronix ignition module? Or points? Or something else. That will determine, for the most part, what resistance you need on the primary circuit.

One problem people new to cars have is terminology, not enough words in their brains to convey the message. Reading back through your post I think what you might be describing is a "lean" fuel air mixture. Not enough fuel for the quantity of air entering the engine. It's controlled by the AFM vane position, so will be tied to engine RPM. But, before you go crazy on the AFM, one cheap thing you can try, that might be enough, is to add resistance to the coolant temperature sensor circuit. It's fixed the problem for many of us here, and it's pretty simple. You can either buy a few resistors and wire them in or get a cheap potentiometer (volume control) from Radio Shack and use it as adjustable resistance. The sensor has a bullet connector on each wire coming and going to the ECU. Put a male and female bullet on your resistor, find one of those connections, and slip it in there. If "lean" is the problem, a little bit of extra resistance will have immediate effect. If it does, you can focus on fuel supply - fuel pressure, clogged injectors, bad AFM, etc. At least it wil give you a better focus. And the second "Bible" is really the one you want. It might be available from another web site somewhere, or maybe you can find a way to get it on a thumb drive or something. It covers the ZX's. http://www.xenons130.com/reference.html

Bought six quarts of 10W-30. For a future break-in.

Crap, I knew something was bothering me when I posted that. I usually point that out myself. The picture I posted is from the wrong FSM. Got 73 stuck in my head, not 74. Forget about points Clomolina. You can still check air gap though. Engine Tuneup chapter. http://www.nicoclub.com/FSM/280z/

The stuff below is wrong for 1974. See the two posts below this one. No the points are under the cap. If you don't know what points are, that's not good. You have much to learn. Anybody who has worked on older cars, will know what points are and how to check them. Newer cars don't have them and many people have never seen a set.

That's not really the best way to check for spark. Put a sparkplug in the wire and place the body of the plug, the threaded metal portion, in contact with the engine, typically the valve cover, where it can be seen. Then crank the engine while watching the plug for spark. Be careful, the engine might start, so put the plug and wire where they won't get damaged if it does. That's one way, there are others. Have you checked the points yet? Examined the inside of the distributor cap? You're jumping around a lot, hoping the engine will start but you should really be going through the basics first to make sure everything is in order. If the PO left the fuel pump disconnected, who knows what else is missing. It may not even have a rotor under the distributor cap.

Don't you have the original marks on the pulley? Several. And the pointer. How did you determine TDC? You can get a lot of crankshaft rotation for not much piston movement.

No, it looks like you have the right distributor for the engine management system. No CAS for NA. And the problems you described are all common to old distributors.

That's cheap, in general, for any oil. Hope it's not a discontinued product price. Thanks for the tip.

You're in the MSA vendor forum. Not the best one fro fixing problems. The springs will compress when you put the weight of the car on them. They just don't have any preload. Can you give more detail than "Lately I've be hearing a clunking/popping noise"? Noises from the rear have many potential causes.

I had that same thin stream of fuel shoot out on to the sidewalk when mine finally let go. Mine was squirting from the connections of the three piece rail though. Note on the newer EFI hose. It tends to creep or relax a little bit over time. At least my Gates brand hose did. I think the newer hose is designed for constant tension spring clamps, not the screw type clamps. Might need to retighten the clamps occasionally until it settles in. That's VR-1 oil, right?