Zed Head

I do have a spare set in the garage for a 280Z. But ~$40 is what the local wrecking yards (PnP around here) charge. I'll bet if you kept an ad on a few CL sites you'd get some offers. People parting out cars looking for an easy sale. Good luck.

Exhaust manifold info would be good. Square port N42, round port N47. I think that the exhaust manifolds used in the ZX cars are different from those used in the Z's also, and they also have a round port for the P79 head and a square port for the P90(A). The bolt patterns are the same but the ZX manifold is shorter from top to exhaust pipe flange (can't use the ZX manifold on my Z with a stock Z exhaust pipe). I just measured them the other day, but one was on an engine. The ZX manifolds also have an O2 sensor port. And the N47 head came in the middle of 77, I believe, July maybe. And the F54/P79 came in late 80. I could be wrong on the N47, pretty sure I'm right on the F54/P79. Also my 76 N42 exhaust manifold has an EGR port. I think that the CA models might have had EGR. The Service Bulletin says they all do, but it's not right. The picture has it right though. The xenons30 site has the 1976 Service Bulletin and various Owners Manuals. Looks like a cool resource when it's done, thanks for putting it out here. p.s. The valve seats should be silicon, not silicone. Tiny detail. And, I don't know the fine details, but in the 1976 TSB page 8, it says that the intake valve seat material was changed to something more durable but they don't say what. Maybe the change happened in late 76. I think that TSB's come out after the model is introduced. Groovy~ Edit - Just saw CO's post. I thnk that the N47 head with the CHTS port is actually the (in)famous Maxima N47 head. Used on the Maxima L24E. Smaller combustion chamber and valves.

B stands for Battery. The thick white wire with the red stripe goes there. E stands for Earth, also known as ground. The black wire goes there. The T plug plugs in to the same hole as the other alternator, the one with S and L beside it. The thing that looks like a small can, the condenser or capacitor, looks correct in your first picture. That should be it. If you were having over-voltage problems it may be that the original issue was with your external voltage regulator. You'll find out when you get the alternator installed.

Maybe you can go halvsies with someone that needs the bushings. $14.39 each. I posted something similar on a different thread - put the price you're wiling to pay for just the washers in your thread. Obviously it's less than $28 for 4. The problem now is that anybody with spares now knows how difficult they are to find separately so may want to hold on to them.

Napaonline has the whole kit for $11.99 per side. $23.98 plus shipping. (Edit - NAPA's poor web site says that they charge a flat $7.95 for shipping - $31.93 to your door. Under $35!). One of the Seattle NAPA stores has it for $14.39, "at the warehouse". $28.78 total. Looks like the deal. NAPA AUTO PARTS

Engineering specs. are usually set after extensive factory testing and include a safety margin. Tightening up the lash will reduce the safety margin. So it really comes down to how important a quiet engine is to you. You might be able to safely quiet things down with some insulation on the valve cover, or on the bottom of the hood. Or you could get a preheater for your engine block and never run it cold. Just saying that using valve lash to make things quieter could be risky. A thicker oil might get you there with no risk. You would think that you could shave a few thousandths off of the spec. and be okay but it's possible also that the valves will heat up faster than the rest of the parts during warm-up and you'll burn/warp a valve before the engine gets hot and loosens up the lash. So you might be okay cold, and okay hot, but too tight in-between. Just a possibility. By the way, I will not be baring with you or any other classiczcar members (that I know of at this point in time).

I've always thought that if people will just say what they will pay instead of looking for a good deal that they would get many more offers. Who wants to haggle over something they didn't intend to sell anyway? How much is being offered?

Pick-n-Pull » Check Inventory The stock washers might still be on the Lynnwood car. They're probably pretty grungy but should get you by.

Now you're past solving the problem and in to trying to figure out what Nissan or a PO did to the car. Like trying to figure out what Pin 21 does. You have a solution for the problem, you can call it solved. Then spend your extra time on exactly how those wires got crossed. Maybe it's a Monday car.

I think he might be talking about FastWoman's theory of "lean mixture drift". Aging electronic components causing a shorter injector open time. Typically fixed by adding resistance to the coolant temperature sensor circuit. If that's the case, then the signs would be slight hesitation and surging during driving. The engine doesn't get enough gas for the amount of air it's pulling in.

Did you use the ZX distributor mount? Maybe your timing is off. As far as the grounding, I meant that the module transistor needs to sink the current somewhere to charge the coil. Typically it's through the mounting screws or a dedicated ground wire. I can't find it explicitly called out in any diagrams. But the diagram only shows two wires to the module, and implies the red and green wires are connected, but doesn't show them. Doesn't show a 5th ground, wire. For example, the GM HEI module, which is known as "4-pin module" doesn't show the 5th wire either, but it is critical to operation. I think that the simplest ignition module wiring you can have is two wires from the pickup coil, one wire to positive power, one wire to ground the negative side of the coil, and the ground through the module. The module has to have a ground somewhere and it can't ground through any of those first four wires. Therefore, there must be a "hidden" ground. Has to be through the mounting holes or some not-so-obvious contact point. Just trying to add some clarity, with lots of words...

The red and green only have voltage when the distributor turns and then it goes +-+-+-+... to trigger the module. The standard test is to measure resistance across green and red, looks like about 400 ohms resistance is right. Page EL-30 in the 1981 FSM shows how to measure voltage with the key turned to Start, maybe that's what you did. The coil, both posts, should have power with the key on and during Start. You do need a good ground through the distributor to get things to work right since the module is now mounted there and grounds the coil through the distributor body, which is what generates the big spark. Weak ground weak spark. Usually the bolts are enough but it's easy to check to be sure. Much fun. Makes you realize the distributor does lot more than just distribute.

The blue wire feeds the ignition module, the tachometer and the ECU. It branches off to each one, not serial, so disconnecting the module won't hurt the other two. That might explain why it ran with starting fluid, the ECU wasn't opening the injectors. The module controls the coil grounding, and the tach and ECU "watch" what's happening. That's an important wire. I haven't looked at Blue's page, but I know that the advice there doesn't cover every detail for every model. Usually there's a note about the exact car that was used as an example and the fact that your results may vary. You're probably in to it deep enough now that you could open up the Engine Fuel and the Electrical chapters of the FSM and feel comfortable.

I've had a weak ignition module before. Showed spark but wouldn't start the engine without starting fluid. It was GM HEI module though. It would probably help you out to measure voltage to the module and to the coil, with the key On and at Start. Just to verify that the components are getting power when they should. then you can worry about if they're using the power as they should. As for using the power correctly, the ZX distributors use a circular magnet that is easily and often cracked. Have you had the ZX distributor apart to confirm that the parts are good?

I originally installed mine to see if I could fix the hot start problem by adding fuel (it helped the engine run better but you still had to wait for the injectors to cool down). Then I installed an AFM with a lean spot at low RPM and ended up using it to get rid of the lean spot. So I tune mine by throttle feel. A lean spot will feel like a lag in response followed by a surge as the AFM vane passes through the area. Not the best fix, since it's probably rich in other areas, but it's a pretty handy band-aid.

Weird that you would have one removed and ready to go. Why would that be? It's not even oily.

Sounds like you might actually have only the Start circuit connected to the new module and coil. There are two circuits from the ignition system at the ballast resistor, one is the ballast bypass for when you are Starting, and the other is the power through the ballast for when you are running. I'm just guessing, but since you test for spark by cranking the engine with Start, and the engine tried to start but doesn't, it seems like power might be going away when you let go of the key.

They show it as available but if you've checked... Funny, when I took pictures the other day for this thread - http://www.classiczcars.com/forums/engine-drivetrain-s30/48693-shifter-return-spring.html - I spent some time myself trying to figure out how to remove the pin. Ended up using an aluminum rod stuck through the reverse check sleeve hole to drive it out. I'm not really in to selling or shipping parts myself but there's a member here called borini63who sells a lot of parts. Might be worth a note. He posts often on zcar.com and hybridz.org also. Seems fair and reasonable from what I've seen.

Looks like any 5 speed from late 76 to 83 will work. The lever on the rod probably changed in 80 though, when they added the reverse check sleeve. Datsun 280Z Transmission Control Lever & Fork (5 Speed-FS5W71B) (From Aug.-'76) Courtesyparts.com shows new ones for about $50. ROD-STRIKI :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com What are you doing?

Congrats. Maybe you shouldn't have called yourself Hardway. I took a rat tail file to the spindle pin bore and removed the high spots on mine. There were some around the lock pin hole. Ran the pin in and out and kept knocking down the high spots until it went in easy. Edit - I seem to be following CO around the forum...

In looking back I think that there may have been times when I cranked my WTS resistance up (I have a Radio Shock volume potentiometer on mine) and still got some rough running. It helped a lot but didn't remove the issue. I think that's why I switched to the hot injector camp, since more duration wouldn't have a huge effect if the gas is boiling in the injector tip, or it seemed that not all of the injectors were affected the same. I don't really know what data might tell the whole story, for me anyway. We'll know it when we see it. Maybe it's a combination of hot fuel in the rail, hot injectors, and an overly hot CTS. Two things that might cause premature vaporization and one that lowers open duration. Lean, lean and lean. Instead of a fan to blow air, maybe a large electric water pump on a radiator hose. Can't go wrong cooling down the whole engine. I only had a tiny water pump pulling water through the AAR block, which then pulls from the thermostat housing (I said head earlier but it was only the T-stat housing). Depending on which way it goes, the water could have circulated through the radiator and open thermostat or through the block and head. But the flow would be low. It's an aggravation, still worth serious thought. Edit - never answered your question about the ZX switch. I know it worked because I heated it with a heat gun and measured resistance. I know the pump worked and was wired right because I shorted the switch leads and tested it. But even on a very hot day after a long drive, with the temperature gauge up on the high end, the switch never caused the pump to run. Somebody with a ZX can probably tell if they ever hear their fan run. I think I've read a few comments where ZX people never really hear it blowing. Maybe it's a poor design.

I can agree with the coolant temp sensor possibly seeing hotter than appropriate conditions. Actually, that was the reason I installed a small electric water pump with the ZX fan switch to run it. But as far as I could tell the switch never closed. Maybe I was wrong and I just missed it. I had it installed most of the summer but removed it late summer. Then cold weather and winter fuel came, now I get hot start problems on a regular basis. Maybe I should have left it on with a toggle switch to clear out the hot water. So close to a solution. A little more supporting data might make things clear.

The ZX FSMs describe the purpose of the cooling fans as to cool the fuel supply lines. I've messed with the switch from a ZX and something I rigged up to push water through the head and found that the switch never closed under the conditions my engine saw even though I would still get the hot start problem. If you have a switch to run your fuel pump before the engine starts you'll hear a lot of bubbling in the tank. It seems like it's well after the rail would have refilled, if it had drained. I think that it's gas vapors, created as the gasoline flows over the hot spots, getting blown through the fuel rail and in to the tank. My guess is that the heat from the exhaust manifolds transfers to the intake runners and head in the vicinity of the injectors and overheats them. There's only a few mm separating the exhaust manifold from the intake runners at the head, and the first cm is exposed, outside the heat shield. You've got radiative and conductive heating all acting on the material that injector body is mounted in. I wouldn't be surprised if the two inner injectors get it worst since they have an exhaust runner on each side. I might take take my digital contact kitchen thermometer with me on my next drive to see what the temperatures are across the intake runners, just for fun. It would be nice to have a scanner and some logging equipment.

The pin 4 theory sounds more reasonable. Maybe pin 21 is an artifact of some idea that didn't pan out. If I had thought more I'd have realized that I already knew there was no pin 21 since I had compared a 76 ECU to a 78 ECU in the past. 76 has more pins than 78 but both work the same in my car. Same exact part numbers. Federal model. My logic on the what the wiring diagram shows stands though, as far as CSV operation. The diagram shows the normally closed relay to power the CSV, opened either by the resistive heater or the heat of the engine. Both twisting the bimetal strip. That's all that really matters for figuring out how to make the CSV work. The CVS operation stands alone, it has power, a relay through the thermotime switch, grounding through the switch to the block. The wires to the ECU are for something else. You could erase the wires to the ECU and still have a circuit that works, with power supplied through the Start circuit on wire 47. 21 is power to the resistive heater in the TS. Funny to spend so much time on something that I removed a month or two after buying my car. No problems starting even in low 30s weather. Maybe it's pin 4.

Is the other stuck in the water pump?