NewZed

Blocks and heads - http://www.zcarz.us/TechnicalInformationPage.htm FSM - http://www.xenons30.com/reference.html It will probably be hard to get the whole FSM downloaded on to your cell phone. The ECU and AFM don't really "care" what 280 engine is in the car. They're what matters. Good luck.

I checked a few things out and from what I've read, the 260Z did not come with EFI. So it's not really clear what you're working with. If you posted your ECU and AFM part numbers and production date of the car someone might be able to tell you what you have. The Engine Fuel section of the 1975 FSM has a nice small diagram showing the pinout of the ECU. You'll be able to trace out exactly where 11 and 21 come from.

The ECU pinouts changed in 1978, maybe late 77. I'm pretty sure that 75-77 is the same, not sure about 74. Nothing after 77 will plug in to your 75 car and work though, and might damage the ECU so would be an expensive experiment. I've also found that 1978 uses the same part number as 75-77, A11-600-000, but Datsun took some pins out and may have modified the internals. A 78 ECU won't work in a 76 car, for example. I tried a 78 ECU on my 76 because they had the same part number but was left stranded after the engine warmed up. I then checked the wiring diagrams and found the differences. A 75 or 76 with the A11-600-000 part number would probably work, but that doesn't look like your problem. Your problem might be with the TPS contacts. I think the damper damps higher frequency pulses than the problem you are seeing indicates.

Your project looks interesting. I have a 76 and it too could use what yours has. Check out this thread re your huge pictures (it took ten seconds for your post to load) - http://forums.hybridz.org/index.php/topic/98587-enough-with-the-large-photos-people/page__p__924956__hl__%2Benough+%2Bwith+%2Bbig+%2Bpictures__fromsearch__1#entry924956 This is a good one too - http://forums.hybridz.org/index.php/topic/64626-lazybroken-shift-keys-rant-does-this-apply-to-you-lets-clean-it-up-please/ - the train-of-thought-puke-it-out-as-you-think-it writing style will turn a lot of people off, especially the ones with the good answers. Just trying to help out. Effort returned = effort in.

McMaster-Carr has a selection. They ship to private addresses. They're like Amazon for industrial products. http://www.mcmaster.com/#o-rings/=bczcyx

Is your ECU still installed and plugged in? Unplugging it might kill the power to one side, the side you'll be connecting to Megasquirt. Page EF-21. There are mini-diagrams throughout the FSM, you don't have to dig through the big one. p.s. Didn't mean to stomp on your reply Ron - timing...

The EFI relay, not the ECU, supplies power to the dropping resistors. Diagrammed on page page 19, if you really want to know. I'll butt out now, just wanted to be sure I was getting my point across. Of course, sometimes it's more fun to put things together without the instructions.

The pin-out for the 1980 ZX dropping resistors is on Page EF-41 if you don't want to chop any wires. There's a description of the resistors on EF-19 and wiring diagrams on 21 and 22. Looks about like your last drawing in function.

FSM = Factory Service Manual http://www.xenons30.com/reference.html MT-4 = Page 4 of Manual Transmission chapter The end is nigh...

Odd coincidence - I just replaced the fuel rail on my 76 last night because the stock multi-piece unit had started leaking at the hoses connecting it together. Started it up and it sounded really rich, realized that I had hooked the FPR up backwards so I turned the fuel pump off to bleed the pressure down while it was running so that I could swap the hoses. It ran for about 10 - 15 seconds!, which feels like a long time when you're waiting and wondering when the engine is going to run out of fuel. I have an aftermarket Airtex pump, rated at ~70 - 95 psi, so my fuel rail was super-pressurised and the fuel had no where to bleed off to. If your 15 minutes is really about 15 seconds, you might have a blockage in your return line, or a clogged FPR.

The ECU doesn't supply voltage to the injectors, it just supplies the path to ground to energize the injector solenoids. So changing ECUs won't help that. The wiring diagrams in the Engine Fuel section of the FSM are small and easy to get through, and specific to your problem. Page EF-24 has a good one. Also, with four 280Zs, you should know that they don't have MAFs, they have AFMs. How it works is also described in the Engine fuel section. p.s. You should add a location or you might get locked out. From what I've been reading anyway.

What does jumping around pretty bad mean? What is the range of jumpiness? I moved my S wire from the battery positive to the starter lug to see if it would smooth my dash voltmeter's needle jumping around. It did but I can't really explain why. ZX alternator in a 1976 car.

There is a good drawing of the shifter components on page MT-4 of the FSM.

I haven't seen an 81 in person, let alone an 81 turbo, but don't most Zs have pumps wired in using studs with nuts. What is this plug that is being unplugged to disconnect your fuel pump? Or are you unplugging a relay? Do you have a picture?

Fuel pressure too high? If you have an aftermarket pump and a blocked line or regulator, pressure can get very high. Temperature sensors lost continuity, sending "cold, give gas" signals to the ECCS?

I think that Tony D might be trying to point you to the TPS. The TPS tells the ECU when the throttle is at idle position. At idle, the ECU adds enough fuel to allow the engine to idle. At about 3/4 throttle it adds a lot of fuel so the engine can go. I haven't tried but I've read that the engine should run, at least idle, without the AFM connected. Yours doesn't so the place to look is the TPS. My 76's AFM number is A31-060-001.

It says rough on the zccjdm page that the 280Z AFM won't work on a 280ZX. The inverse should be true. Did you measure the resistance across pins 6 and 8, and 8 and 9? What were those numbers? Your fuel pressure is high, as you noted. If the gauge is between the filter and the rail, there would not be much pressure drop to the injectors. If it's before the filter you could get a high reading. High fuel pressure will richen things up. The main reason to "tweak" an AFM is because an engine wasn't running right. Sounds like buying someone else's problems. By the way, nice formatting on your message, but a few capital letters might help you get more responses. Effort returned proportional to effort in. Just my opinion. I think the mods have given up on grammar policing, they're overwhelmed. No caps really only works for e. e. cummings...

CTRL -, 0, and + will resize the viewing area if you're using Windows. Unfortunately it resizes the text also but it's a quick way to get a look. CTRL 0 takes everything back to where you started. Google's Picasa is free and will download from your camera and export to a smaller, predefined size. Kind of clunky but it works - http://picasa.google.com/#utm_campaign=en&utm_source=en-ha-na-us-bk&utm_medium=ha&utm_term=picasa

Si. Maybe there have been more measured results than have been posted in the thread. I just haven't seen many focused results, like actual temperature measurements at the back cylinders, or running more races before the back cylinder exhaust valve seats loosen up, or more boost possible since the modification, or similar. It seems like many people are doing this but it's not clear if they're really getting any benefit. I'm just trying to draw out some more before and after anecdotes about this proposed improvement. Something measurable. Maybe some of the other people who have done this will post their results.

Sounds like something electronic. Solid sate devices do strange things. Grounding the coil warms up the ignition module and the Pin 1 ECU circuit.

In the Factory Service Manual (FSM), Air Conditioning refers to air heating also. The section is full of drawings and descriptions of how the air heating and cooling system works. http://www.xenons30.com/reference.html The 1977 download file doesn't unzip in to chapters, so it's a little more work to find what you want, but 76 and 78 do.

I've read the whole thread and it has drifted some from the original Post #1 (not surprising after 22 pages) but Ricky's post has kind of brought it back on topic, to specific problems at the back cylinders. Ricky stated that they "added the by-pass lines after we had some issues with the engine losing compression on those cylinders which was caused by the exhaust valve seats losing their seal. We used a vacuum gauge to test the valve seat to confirm this." He then reports a stable 190 degrees after ten laps as the result, as opposed to creeping up over ten laps. The question of compression loss and loose valve seals due to localized heating is still unanswered. If this mod has fixed that, then the engine should produce more power over the course of the race (no more compression loss), with no loose valve seats at the end. That would make the result of the modification more clear. I've read the whole thread before and I recall waiting for the definitive results to solving the dropped valve seats, or detonation at 5 and 6 problems, but never really saw it. The closest I recall was a report of producing equal, sharp, "sudden onset" detonation across all cylinders. Anyway, thanks to everyone who does this kind of work and shares it. It's fascinating stuff and I wish I had the resources myself to add more to the discussion.

I thought that the focus of this thread was to find a way to prevent overheating at cylinders 5 and 6, to avoid problems like dropped valves (Post #1) and detonation. Ricky is just reporting a lowering of coolant temperature in general. Which seems a little odd actually, since the same volume of water is flowing past the temperature sensor and the same amount of heat should be produced by the engine. It's interesting work, but I don't see the connection between specific hot spots and overall heat removal.

One possible reason for the engine to idle higher with the flasher fuse out is that the alternator is not working as hard (burning up your wires). Did the ammeter wire smoke before the fuse box upgrade? There's a pretty good wiring diagram at this link, in the FSM - http://www.xenons30.com/reference.html

The descriptions of wire gauge in the FSMs, plus the Courtesy Nissan web page support the premise that Br (Brown) is actually what is now called red and is 0.3 mm^2 in diameter. http://www.courtesyparts.com/kb_search_result.php?chassis_id=59&keywords=fusible+links&Submit_Button=Go&cat=1 I think that Post #12 in your first link is on the mark. The wire gauge is listed in the FSM. The only reference I have seen on the internet to red as 50 amps is the atlanticz site, and on the atlanticz site, they call red out as 0.69 mm^2 not 0.3 as Hyuri says (in your link). It would be great if blue would address that issue someday on the atlanticz site, since tens, hundreds, maybe thousands of people take it as Z gospel. Luckily it only really matters if you have a short. It's interesting that the ZX fusible link cover still shows Br for link color, but the stock link looks red.