NewZed

You might also add a condenser/capacitor to the W wire. The HEI module is supposed to work from zero crossing, positive to negative. But in the the ignitor swap it's actually working from positive TO zero, the ECU signal. So it's not quite right for the application and might be more susceptible to noise. Just a guess. I've fixed tachometer problems with an extra condenser. You might also move the ground point for W farther away, and/or just make sure it's a good ground. Maybe move the whole assembly away from the coil to reduce potential noise.

You might switch the G and W wires. The pictures in Skittle's zcar.com writeup are gone so can't tell what he found that worked. But in normal use, if you get G and W swapped, timing will be off. It won't hurt anything, but it might just make the triggering more consistent. If you want to be sure that it's tied to the HEI module, put the old ignitor back on and see if the new problem goes away.

Cause, effect, correlation? Did you install the module to fix the 2000 PRM problem, or for some other reason? Why did you install the module, and what was it doing before you installed it? Describe the engine management system also. That will help.

Don't get distracted. Tony D often assumes the worst and misses the details. It was obvious from your latest posts that you did go back to square one, properly. He might come back with some defensive comments, so be ready. Add an addendum to your verse, or pick another one. I like the one you chose though, it works on the internet.. The hints he was giving are about the gear on the drive shaft. It's a press fit and can slip. If it did you might find that adjusting a tooth one way puts you on one side of the timing mark tab, and one tooth the other way puts you on the other side. I'm just guessing, I don't know how many degrees one tooth gives, you'd have to do some math. Don't forget that the distributor turns at half crank speed. It sounds like your saying that timing is too advanced and can't be retarded. So you would want to rotate the CAS wheel in the direction of rotation so that spark happens later. The CAS hole hits the light beam later. While you have it out, check the gear for a mark also and see if it lines up with a mark on the shaft. I'm just guessing again, but I seem to remember looking at some later shafts that had that. Engine parts are made to be assembled by line workers so often have extra markings. You might also, before you spend too much time on it, try removing the clamping screw so the CAS can move farther and setting timing correctly for a test run. Use a small c-clamp or some vise-grips temporarily in place of the screw. To your earlier point of "if it works doesn't mess with it". You might find that getting the mark on the tab doesn't work for you anyway.

You're right. Got lost on the edges. So if he knows stock wheel offset, he knows what he wants to know, from the table of dimensions. Factory numbers, not worn-out car measurements.

Dang. I guess the charts are inconclusive then. If a 195 and 175 width tread give the same tread, I assumed zero offset. Otherwise, the extra 20 mm would be a + or a - to tread. Unless by "tread", Nissan means WMS to WMS. Maybe a translation problem. I don't know why they'd spec. tread based on tire, and show one tread, but two tire sizes. Or maybe "tread" generally means WMS to WMS in car suspension world. Better than a crossword puzzle..

Pretty sure you can logic-out that tread width = what you're looking for. Two tires, different widths = zero offset. Zero offset means tread width = WMS-to-WMS. Measured from tread center. Zero offset. It's the only way to make the facts coherent. Note the note about "at curb weight". Tread width changes. Edit - changed same to different.

But is the timing mark in the proper range now? Tony D's hints may still be in play. I learned something about the turbo engines. Win-win.

Nissan called out a "tread" width, with certain tires. Might be a useful number. Your track width differences don't seem to match though. Only a 0.3" difference. You have 1.5". Typo?

What's a WMS?

2+2's and Turbos use CV's.

There appear to a couple of 280ZX's at the Arlington Pick n Pull.

If you mean that the two pictures are oppositely oriented, then you are correct. Your red arrows are pointing at the same thing. At a glance, the drawing right side half moon looks "bigger" , which would mean closer, therefore higher. But close examination shows that Nissan drew the edges of the raised half and tried to shade in the face. Not a great picture, really, and no words describing it, like they do in the 280Z instructions. But, in the end, it's orientation of the rotor that matters anyway. You would have been better off if you'd never seen that picture.

I think I misdirected in Post #19. Because I misinterpreted the picture in the FSM. Had my half-moons backward. I re-oriented the pictures to make it easy but still mistook the direction of the half-moon depression in the FSM drawing. I said it was right, when it was wrong. In Post #13 the OP says he started this adventure because he couldn't set his timing. So, in sum, it seems like he reset everything 180 off. A worthy attempt, just didn't hit the mark. Probably just needed a one tooth move, to get the CAS within the adjustment range. Resetting everything, while on the compression stroke and realizing that the half-moon depression in the hole faces backward should get it done. johnc was right.

Curious, since all we have out here are pictures from various angles. Is the rotor electrode 180 degrees off from the half-moon on the bottom of the shaft? Or is it some odd angle? And is it the correct rotor, with only one hole? You haven't really confirmed that the rotor is incorrectly oriented on the distributor, looking at only the distributor (forget about the drive quill in the engine). Could be that there are other rotors that will fit your distributor. Or the PO just drilled another hole to reclock the rotor. In the same vein, you could drill a new hole if you wanted to.

I don't see 604 046 anywhere on the official Nissan factory Technical Service Bulletin. That's the one I'd use. The jimwolf page might be misleading. Edit - actually I did find it. The other ones might work too though. Are you running an automatic?

California Datsun product will be far from a Rebello product, in quality and power. The company used to be called Datsun Parts LLC. Search the web for Datsun Parts LLC. Beware. And Rebello's 3.0 will certainly cost much, much more than the California Datsun engine. If CD's price is in your range be prepared for a shock when you talk to Rebello. They are in two completely separate universes.

Here are a couple of sources. But if you're running the 1978 NA ECU, you must be running an NA distributor also, not the CAS that the ECU needs. The 1978 ECU doesn't do ignition control. You need the whole ECCS (S for System), or aftermarket engine management like Megasquirt. http://jimwolftechnology.com/wolfpdf/ecu-id.pdf http://www.jatan.net/tsbs/040359.pdf

So everything is now narrowed down to the bottom of your distributor shaft and the top, since the oil pump shaft is correct. Focus on the screw hole on the top and the half moon on the bottom. Those are what oriented the rotor to where the engineers intended it to be. The rotor will spin around to wherever without that screw. If the rotor screw is in, then the screw hole seems to be off. I tried to mark where things should be but might have "screwed" up.

Vacuum gauges don't tell you if there are vacuum leaks. They only tell you how much vacuum is in the intake system. Very general information, along with small details about variations between cylinders. The simple tricks for ID'ing vacuum leaks are to remove the oil filler cap and see if the engine dies, or a vacuum hose and see if engine RPM changes. You need a feel for how engines should run though to get much out of it. You don't have to go through every single thing. Just the things you're studying. Fuel pressure, for example. You said low pressure in your title, then reported some numbers, but didn't acknowledge that the pressure numbers were correct. You said that you can hear all the injectors working but said above that you can tell #1 isn't. So which is it? Listening to 6 at a time is not the same as one at a time. And you didn't talk about the noid light work. These are the details that will make the difference. If you want to maximize your productivity when looking, look through the Engine Tune-up chapter and do everything described. Could be that your valve lash is off.

"there are no vacuum leaks whatsoever" How do you know this? It seems like you're not even using the FSM, that gets mentioned endlessly on any Z car forum you can find. You can check if the injectors are functioning using a screwdriver and your ear, or a mechanic's stethoscope. And some small Christmas tree light bulbs to check power pulsing.

The XR700 without the optical trigger is no better, probably worse, than a later model 280Z ignition system. Any Z igntion system after 1978 will flow more current through the coil and allow wider plug gaps. Crane developed the XR3000 as the next level ignition module. The XR700 still requires a ballast resistor to limit coil current. It was designed to replace points with an optical trigger. Without the optical trigger, it's pointless. Which is ironic. In other words, you're spending a lot of effort on something that's not that special. Install a GM HEI module and you'll have a more modern high energy ignition system. And it's easy to connect to the 280Z pickup coil leads.

Nah, you missed my point, which is actually your point. Don't get defensive, I'm on your side now. The rotor should point directly to the depressed side of the half-moon Yours doesn't. It's not even 180 off, it's 160 off. Nothing to do with TDC, as you said. Why haven't you taken the rotor off yet? That will tell you what you need to know.

Actually, looking at the pictures, it looks like the rotor is more like ~160 degrees off, not 180. Hard to be sure since the pictures aren't from exactly the same position. Something weird with the CAS shaft or the rotor fit.

Rotated your first pictures just to show what you're talking about. The oil pump drive quill looks right but the top of the CAS shaft with the rotor is 180 off. It's either the rotor or the top of the CAS shaft that's not right. If the bottom fits, that's all that's left.