NewZed

Your other thread didn't get deleted, it got moved, to the Tool Shed - http://forums.hybridz.org/index.php/topic/102031-overheating-getting-frustrated/ If your engine cools off when you're moving, and heats up when you stop, then you most likely have a problem with air flow through the radiator. The radiator is where the water flowing through the engine loses it heats, radiating it away to the air passing by. No air flow, no cooling.

The 1975 FSM shows an ammeter in the wiring diagram. So it looks like the 1975 280Z is the only 280Z that came with an ammeter. My 1976 has a voltmeter. For what it's worth, every little connection that I cleaned up on my 35 year old car added a little more speed to the wipers at idle (my best indicator of amps available). The EFI harness connectors at the fusible link, the four fusible links under the covers, the battery posts, etc. they all count. A corroded connection is milliamps wasted in heat, and the milliamps add up. I have also found that an old 1978 alternator that had been sitting unused in a non-running car and weather for ten years, produced more amps at idle than a "new" rebuilt life-time warranty alternator from OReilly Auto.

What kinda car and engine are you working with? The FSM has some good troubleshooting procedures and the first few pages of the Engine Fuel section are full of information about how things are supposed to work, especially for the 280Z models. There are several different reasons for no fire, but overall, the ignition system is pretty simple. For EFI, sometimes no fire (spark) is actually no fuel (injection).

Year of car and engine, and any modifications needed. Download the FSM for your year and go through the Engine Fuel section. It will describe how to test the TPS to see if it's working right. Green in your TPS is probably bad. Your description of revving, dying and hard starting sounds ignition module related. But more details about temperature, how long you're holding at 4000 and what you mean by "hard time starting" would give more clues. Actual numbers for fuel pressure and resistance at the sensors would help also. Also, describe what you mean by 80% power. Full throttle, half-throttle, etc. 80% of what? Everyone loves a puzzle but you have to give some good clues.

If you didn't read the information in the link below, you really should. If you're quick, you might be able to edit your post before it gets sent to the Tool Shed. Good luck. Read the the first four threads here - http://forums.hybridz.org/index.php/forum/68-new-members-forum/

In retrospect, where things went awry in cjmeredithjr's ad, is when he started goading people in to making comments. Basically he broke the no comments rule in his own For Sale thread. When the feedback he provoked came, it was then removed by the admin. Not a big deal, just disappointing that we couldn't continue the conversation that the OP started. There wasn't serious "bashing" just what seemed some reasonable questions and comments (one post that was removed referred to the dropped valve seat in this very engine - not sure why that was taken out, that's true valuable information). There was also a comment about how the engine was "built by the best" but that seems to be gone also. Maybe best for all that the For Sale ads be locked from the start and response by PM only. Then we couldn't respond to the goading. Here's the buildup in the L28 Turbo 550RWHP... ad, from the OP - "Let's hear some reasonable offers, someone is going to win big on this one!" "Man, this must be one crappy economy when you can't even give away a basically brand new engine." At least he replied to the last comment. Apparently it makes 550 RWHP before nitrous. "Hey, another comedian, you must mean 850RWHP." Maybe he'll respond to a separate thread with an invitation, and talk a little about the engine. It looks interesting. But it's all good entertainment. Thanks for the great site.

Maybe there should be some leeway in allowing comments, depending on how outlandish/outrageous the claims are. Then the effort from the moderators would scale inversely with HP or price. If you post an ad for results never before or rarely seen, be ready to take some questions. I just wanted to throw something out for discussion on ways to avoid having people use the For Sale section to tell stories about their accomplishments or indirectly advertise their shops, without putting in the same effort required if they had posted in the other sub-forums. Another way to do it would be to start a new thread with a link or reference to the ad in question. That would fit the tone of the site best, I suppose, without muddying up the original ad post. I really would like to know how to get 550+ RWHP from an L28, and wonder how long that power would be available. Thanks for listening.

People come to Hybridz to learn from the best about how to get the most from what they have. They expect that bogus claims of technical prowess will get called out and exposed. It happens all of the time in the Technical forums. There is no reason for things to be different because the claim is in a For Sale ad. In fact, I would expect the exposure to be even more extreme in a For Sale ad, since you don't want Hybridz members to get ripped off. If all of the posts from members who point out the flaws in someone's claim get deleted, then the moderators are essentially supporting the potentials scammer's attempt to scam, and shutting out the people who know better. Not leading the lambs to slaughter but stopping the members who are pointing out the wolf. I think that if someone makes a claim in a For Sale thread that they should have some data to back it up, or take some heat for their unverified claims. Or they should be made to take out the claims, and just sell the collection of parts they're trying to sell. I know that the Classifieds are a pain for you guys but there's no reason not to have the same standards for the For Sale section as the rest of the forum topics. Unverified claims should go to the Tool Shed.

I see what you're doing now. I missed the .600" quench area on the piston that matches the same on the head (basically I missed the point of your description and the point about your custom pistons - my fault). Looks like two squish areas, a small and a medium, across the combustion chamber. I would think that you would need a certain ratio of squish to un-squished to push enough of the unburned charge to get the full benefit. I hope you have enough squish there to get some solid effect. Looks interesting, good luck. Hope I didn't get your thread off track.

Seems pretty common for msd (maybe not digital-6). Search "msd tachometer". 2 pages.

Curious - you said you milled the head to get some "quench." But you're using dished pistons. To get a properly shaped "quench" wouldn't you be better off to mill a pocket that matches your cylinder head chamber, in a set of custom pistons? It looks like the way you're going, you'll just have an odd shaped combustion chamber, with no real "quench" or "squish" action (as I understand the meaning of quench) during the compression stroke.

Nissan used crimped splices throughout the wiring harness at the factory. Even the untampered harnesses look tampered.

I have a 76 and all I can hear when I hit Start is the starter turning and the engine cranking over. Too noisy to hear relays clicking and the fuel pump running. Try removing the small wire from the starter solenoid (it just pulls off) and then turn the key to Start. This should power up everything except the starter motor. Then engine won't turn over so you can more easily tell what's happening. It's a good way to test the fuel pressure also. You're better off to use the 1976 FSM, Engine Fuel section, for your testing also, the "Bible" is somewhat generic and might miss the tests specific to the 1976 car. http://www.xenons30.com/reference.html

You have quite a way to go. It looks like you need more than just ignition system wiring help. I saw a coil and the top of a distributor cap. Take the cap off the distributor and show what's inside. Take a look up under the passenger side dash and see if there is a small metal box, about 5" x 5", with a strip of about 7 wire terminals on it, bolted above and to the left of the where the fuse box should be. Take a picture. You should probably spend some time figuring out which of those harnesses if a 1975 car and use that one. That way you'll have the right connections for the relays, etc. that might still be in the car. Although it looks like the car might have had everything stripped and you're starting from scratch. That's a big job for you, especially if you're having trouble just figuring out how to wire your ignition system.

I'm a Megasquirt rookie, but from what little I've learned, it seems like you might be missing a pull-up resistor on the distributor output to your tach circuit and/or the wire to pin G on the HEI module (shown in mobythevan's diagram. That might give an inconsistent signal to the tach circuit in MS,or an inconsistent signal to the HEI module. Causing sporadic spark output in either case. Just a guess. Transistors tend to get destroyed by voltage spikes, caused by things like static shocks or bad voltage regulators. Maybe you've got some stray voltage. Have you been connecting and disconnecting the battery or charging it a lot over the last year and a half? Again, just a guess. Consider carefully disconnecting your MS board before connecting chargers or jumping the car or whatever. Just a few ideas for a good puzzle. Good luck. Edit - you might consider drawing out your basic circuit diagram so people that do know can see if what you've done should work or not. Also, confirm that you have the 1982 distributor with the internal CAS.

74s and up came with electronic ignition. There is an ignition module by the fuse box. If you get, or have, a distributor from a 74 to 78 Z you could just connect a few wires from the original harness and have everything you need, including a working tachometer. If you don't have the original ignition module, you could get a GM HEI module and wire it up. There's not much wiring to an ignition system. Power to the coil, ground from the coil to the ignition module or points, a wire with resistor to the tachometer. What do you have left from the 75 harness? Do you have a distributor? What type of coil? If you're lucky, you haven't torn too much out from the original 1975 system.

Lucky coincidence - I have a 78 EFI harness in the garage and I was just looking at it (trying to figure out the Pin 1 path to coil (-), but that's a digression). Here is a picture of the piece that you're missing. It supplies power to the EFI relay which powers the injectors and a few other things. The ring terminal on the end of the white wire bolts directly to the battery positive. If you rig up your own connector you should make sure you use heavy gauge wire. Those are two ~40 amp (what seems to be the consensus for green) fusible links in line. Edit - I believe that that is a typical Nissan factory splice combining those two wires from the battery to the connector.

You should have 12+ volts at the injectors full-time when the key is On. The ECU works by providing a ground for the circuit to energize the injector solenoids. It doesn't provide power, it provides a ground. If you don't have 12+ at the injectors, you might have a blown EFI fusible link (or you missed something when you put the new harness in). They are the two green links from the battery positive post. I think that they are pinned to the side of the relay box by the battery.

Edit - did some more reading and see that rotating the distributor is the proper way to set timing for the distributor mounted CAS. The FSM is pretty useless for any details of setting timing via adjusting the CAS, with the ECCS system. Good luck.

Just for comparison, how much does the Stag weight, compared to the a Z? In dollars per HP, with maximum simplicity in mind, it seems like a 2.8L long block from a 280Z or ZX might be an option. Just swap your carbs, etc. over and re-tune. With an auto, lower RPM torque is what you want anyway. Even though the 2.6 is fresh, an extra 7.6% displacement would add some go. That was Nissan's thinking anyway.

Those look like the kind with the removal metal clip that is a pain to get out and easy to lose. Volvo connectors are easier to use, with a non-removable spring clip, and probably of higher quality, if you can find a newer car in the junkyard (cheap), or buy new if you have the extra cash.

Pretty sure you can just grab them by hand and pull them out. They install by hand, along with a tubular metal inner bushing. The stock original rubber bushings are bound to a metal sleeve that has to be pressed out before the typical poly bushing can be inserted. If all you see is a hole with a metal sleeve then someone may have burned the rubber out already, leaving the outer sleeve.

Whoops, I missed the automatic part. That makes it difficult. If your timing is close and you have strong spark and the valves are opening and closing, starting fluid should get you a short burst of power. It sounds like your problem now is too much fuel. You described flooding, with soaked spark plugs. You might try drying the plugs out, then hitting it with the starting fluid before the next starting attempt. If it starts but then chokes on fuel and dies, at least you'll know everything is working, but with too much of the fuel part of the equation. You could even disconnect the injectors to avoid flooding, and fouling the plugs, entirely. If it starts and runs, then you can focus on the too much fuel problem alone. The injectors are held open for certain amounts of time depending on a list of factors, including how far open the AFM flap is, where the throttle blade is (TPS), how warm the engine is (water temperature sensor), air temperature, etc. A stuck or shorted TPS (showing WOT to the ECU), broken temperature circuit (showing a stone cold engine), or a stuck AFM flap (showing lots of air when there's little) are some of the causes I've seen described for extra fuel. CSVs have been known to get stuck also. Good luck. Edit - you said it's in a barn. Mice love to crawl up those long plastic air ducts to build their nests. I've seen nests in the air filter housings of a Buick, and the blower motor of a 78 280Z. Might be worth pulling the air inlet hoses from the AFM to make sure it's all clear in there, and the AFM vane moves freely.

There are a variety of ways to narrow the list of things that work and those that don't down to a manageable level. If you have confirmed that you have spark when cranking, try lining up the two lines on the distributor adjustment plates, by the locking screw. I've found that when the timing on my engine was correct, those two lines were aligned. Probably an assembly aid or done for future mechanics. Then squirt some starting fluid in the intake manifold and see if it starts. If so, you have a fuel problem, probably injectors not firing. To confirm that the wire to the ECU and the ECU operation is correct, for firing the injectors, connect a jumper wire to the negative terminal of the coil and leave the other end hanging, turn the key to On, then quick;y tap the jumper to ground multiple times. Every three times, all of the injectors should click. This trick has been described by Tony D on multiple forums, and the reason it works is described (with a little bit of extra thought) in the Fuel section of the FSM. Two simple ways to get an idea of what to focus on, fuel or spark. You said that you knew you had both, but you might as well confirm separately. If your injectors are opening and the engine doesn't start, then you should have wet, gassy spark plugs. Even without injectors, I believe that your CSV should be dumping enough gas to get it to kick. The ignition relay sends power to many different places, maybe you missed one with your converter harness. As for your timing, put the car in high gear and slowly roll it while shining a light on the crank pulley. You'll find the notch. Then mark and while you're down there, clean up the timing tab and mark Zero with some paint. These engines are just a collection of simple devices. Just make each one do what it's supposed to do and you'll have a running engine. Just dumping a few thoughts out there...

Spark plug wires in the proper order for counter-clockwise rotor rotation?