NewZed

Your jumper wire just did the same thing the fusible link did. It melted because it had too much amperage through it. The components on that circuit,including your fuel pump, should not be pulling enough amps to melt the link or the jumper. There must be a short somewhere in the circuit. By the way, red may not necessarily be a 50 amp link. There is some confusion about it in the 280Z world. I'm not familiar with ZX's though, but you should probably confirm it or you might melt the next weakest link in the circuit with your 50 amp fuse. The wiring diagrams should tell if one of the components that you upgraded has a direct connection to ground, that you might have reversed.

The fact that "sometimes" you have to push the pedal to the floor suggests that your slave or master cylinder is going bad. Pull the rubber boot off of the slave cylinder and see if it's full of fluid. I had a slave cylinder fail due to bad sealing mid-stroke. It looked like it was moving correctly but it was leaking in the middle of pedal travel. If you're sure the hydraulics are good, then it's possible you have a short collar in place when you need a long one. But if that was the case, I would expect your slave cylinder piston to get pushed out of the cylinder since it is self-adjusting and would just take up the slack (as I understand it). Here's a link to collars either way - http://zparts.com/zptech/articles/trans_swap%20parts/4tobear_specs1.html Edit - these are examples and your situation might not be shown, but it gives you the idea.

These are popular - http://forums.hybridz.org/index.php/forum/63-ems/ There are threads out there about the Z31 ECU but I'm not sure it's much easier, better or cheaper than the aftermarket options in the sub-forum above.

If he still has the external voltage regulator, you might check that out also. One of the wires to the regulator is hot, a direct connection to the battery. Unplug it and see if the light goes out.

How about a picture of the debris from the header?

You might have a broken tension rod on the front suspension. They break sometimes if the rubber bushings are replaced with urethane. A broken rod will let your transverse link (aka control arm) and wheel move back and forth. Just a guess, but worth a check.

WB02 means wide band oxygen sensor. It allows a higher resolution signal to be produced than with the narrow band, and with the right controller gives actual Air Fuel Ratios (AFR) over the useful range that you would expect from a well-tuned engine. Here's a link to one of the most popular units - http://www.innovatemotorsports.com/products/lc1.php Here's one with a gauge - http://www.innovatemotorsports.com/products/MTXL.php One more thing - the graphs in the link below show what you are probably reading, either narrow band or wide. The slope of the curves, negative vs. positive, is even different for narrow vs. wide. You should figure out what you have. http://www.carcraft.com/techarticles/116_0402_innovate_air_fuel_ratio_meter/photo_07.html Just one example. Not an expert, just stuff I've picked up here an there.

This thread should help you - http://forums.hybridz.org/index.php?showtopic=48124 Since I'm here - what do you mean by "2t" in your description of your engine mods?

CSV is Cold Start Valve but maybe the turbo motor doesn't have one. I browsed the supplement and didn't see it. Confirm fuel pressure. Just loosen a hose clamp on the fuel rail and see if gas squirts out. Your FPR and pump should hold pressure for at least a minute or two after trying to start. The dropping resistors save the injector circuit from overheating. I would not run with them bypassed if you have stock injectors. Alright, that really is all I know. Good luck. Confirm fuel pressure.

You're welcome. But. I think that dropping resistors are matched to the injectors (according the FSM the 81 turbo engine uses a dropping resistor, it's described in the 81 Turbo Supplement) to control current flow through them. The ECU or E.C.C.S just supplies the ground. I could be wrong though, I don't have a turbo motor. You could check you CSV connection for 12 volts when the key is at Start, then pop the CSV out, disconnect the small wire to the starter so it won't crank, turn the key to Start and see if the CSV squirts. Or loosen the hose clamp and see if it leaks, or something similar. A lot of different ways to verify some fuel pressure even if you can't measure it. On the 81 doesn't the fuel pump prime for five seconds when you turn the key to On? You should be able to hear it. I would think that if you had some fuel pressure in the lines, that the CSV would supply enough to at least give you a pop or two. Some people have reported running the engine on a stuck open CSV alone. You might supply a direct 12 volts to the CSV, jump in and see if it starts. Just a wild idea. That's all I have. It sounds like you have everything covered except confirmation of fuel pressure in the lines and injectors opening.

This thread has some good stuff in it. Jump to #16 for the apparent answer. You might have enough current for the lights but not enough to open the injectors. http://forums.hybridz.org/index.php/topic/97671-1977-280z-fuel-injection-problem/page__p__917068__fromsearch__1#entry917068 Are you sure that you have good fuel supply and pressure?

Maybe they were monitoring a converted signal from the Megasquirt board, not the actual VR output.

The variable reluctor generates its own voltage. There is no +/- 5 being turned on and off. (Edit - on the oscilloscope) The Megamanual does a pretty good job of explaining it. http://www.megamanual.com/ms2/pickups.htm

It is fairly well described in the Engine Fuel section of the FSM. The ECU grounds the injectors, allowing current to flow and opening the injectors, off of a pulse from the negative post of the coil,when the coil fires. This circuit also runs through the tachometer, so if the tach is disconnected the injectors won't fire. The injector connectors should have 12 volts on both wires, when the key is on. The 1976 280Z FSM chapter files at www.xenons30.com are well-copied and broken up in to individual chapters, so very easy to find what you need.

The cold start valve only adds gas when the key is turned to Start. Otherwise it just sits there. It is only for Starting. The Air Regulator doesn't add "extra" air. It just bypasses the throttle body to increase the idle speed without having to open the throttle blade. But the air is still passing through the AFM, therefore is metered. Did you block the hoses, or just connect them together? Without the Air Regulator, the engine will not keep running until it's warmed up. That might explain the need for the quarter. If you can't fix the Air Regulator, you're better off to block the hoses, and use the idle screw yo keep it running, at least for tuning purposes. The return spring on the brake pedal will bring the pedal back up. You either have brake lines full of air or a bad master cylinder, or both. If it's air, you should be able to build some pressure by pumping the pedal. Make sure that your water temperature sensor works and is connected to the right plug. It has the same connector as the thermotime switch. If it's not connected properly and working, the ECU will keep adding gas through longer injection times like it's stone cold. The most effective way to check is at the ECU connector. That way you know that the the sensor and all of the wires are working. There's a table of resistance vs. temperature in the FSM Engine Fuel section. Pick your engine temperature and measure at the sensor's ECU connector pins. If one temperature is correct, odds are everything is working. Your problems are very common to all of the old "ran when parked" EFI Z cars out there. I've gone through the same scenario on two so far.

Where are you?

If your 260 has an ammeter, it will probably be like the 240Z and need the diode. The MSA plug might even work. If it has a voltmeter, then the 75-77 280Z conversion would probably work. I don't know when they switched, but I think the ammeter is what determines the need for the diode. You could compare wiring diagrams to be sure you get the wire colors right, if you don't want to test the individual wires.

Have you tried www.classiczcars.com? Much more likely to get some good help over there.

Where?

I think that Dexron is, in general, associated with ATF and not gear oil. Maybe it's just mass-media marketing. When I see "Dexron", I think ATF. Google "Dexron" and ATF comes up. Maybe there was an 80W-90W Dexron fluid available in 1983. I just put it out there as a possible point of confusion. Maybe there were two manual transmissions for the turbos, one used Dexron, one 80W-90W. I've been in the transmission sections of the FSM and haven't seen anything describing a manual transmission that uses ATF. Dexron is actually a GM trademark for ATF fluids. http://en.wikipedia.org/wiki/DEXRON

This might explain where the ATF vs gear oil confusion comes from. The FSM implies either. The picture is from the Maintenance section of the 1983 FSM.

I have read that a high volume pump can flow more fuel than the return lines on a non-EFI tank and lines can handle giving high pressure no matter what the FPR is set to. You might need to re-plumb your return line to run that high pressure EFI-rated pump.

I think that you lost a lot of people at "MAF" and "blowing tons of money for replacement parts." It's a sad, lonely road that no one wants to travel with you... DCZ is right, if you get the FSM and read the Engine Fuel (EF) section, you'll be able to describe your problem better. http://www.xenons30.com/reference.html It revs really high but barely moves? Automatic transmission? Read the AT section also. Even if you don't get a solution here, you should be able to save a lot of money with your future mechanics.

Just like the drawing in Post #10. ??? I worry about the world...

From what little I know of the other Z years, the 1974 260s came with both mechanical and electric fuel pumps, in series. Maybe your electric pump is still there. If not, at least the wiring and plumbing should be. Crawl under the car and look around at the front of the gas tank.