Zed Head

VR is short for voltage regulator. 14.5 volts is good, using a good meter. The dash gauge is isn't very good. I only asked because it was undefined. One man's "way over" is 16 volts, anothers is 14.5 I'm a numbers guy.

Here's a source. It will probably look like the one he has though. http://www.zcarsource.com/engine-harness-240z-260z-280z-280zx-300zx_8_56708.html

The fuse is supposed to melt when it gets hot. The only explanation for getting that hot at the fuse connection is that you had high resistance there, creating a hot spot. A balance between the local hot spot and heat dissipation that allowed the cover to melt before the part of the fuse that was supposed to melt melted. In short, dirty/loose fuse contacts. Common on the 240Z's, I believe, not so much on the 280Z's. I'd clean them all up. Weird that you have multiple problems happening at once. As noted, the headlights and the tail lights are two different circuits. I went back and did see this though - "I was still showing way over 12V on the dash volt gage". How way? Could be that the excess heat was caused by excess voltage, and excess amps. Maybe your VR is going bad.

A simple shorted tail light bulb socket could blow the fuse. I had one of those. But the fuse destruction and high heat under the cover shouldn't have happened. Have you had the fuse box assembly out? Maybe you shorted some wires behind the that fuse. You said it happened all of a sudden. Implying that something moved and shorted while you were driving. I would check all of the things that you've worked on recently. I didn't catch where you wired in your fans and relays.

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Two completely opposite experiences. Fascinating.

The headlights are on a separate fusible link. Maybe it came loose. Not sure what else is on the circuit. The dash lights on my car will go off when the tail light fuse blows. Same circuit. So if you don't have dash lights, you may not have tail lights either.

This is with no separate hanging shims? That's the question at hand. Any pad will work and not squeal if you use the factory shims.

Probably doesn't help, but the factory harness looked like it's been hacked and patched when it was new. They used a lot of crimps and "tap" junctions. Then buried them in insulating tape. Even if he gets a replacement harness he'll still have to do some meter work to get power where it needs to go. He might be in the same boat with a new harness as he is now with his old one. Just saying...

Coolant is conductive. If you sprayed it all over the engine's electrical parts you might have some new electrical problems.

Yes, the anti-rattle pieces are installed. Odd that they call them anti-rattle if they're actually anti-squeal. It's not a question of pad quality, it's how to keep them from squealing. Are you running any of the pads you mentioned, without added shims and without any squealing at all, cold or hot?

The first thing you should do is to stop thinking in terms like "all that crap". Better to understand what the parts do and how they work so that when they're gone you'll also understand why the engine runs differently. The factory timing specs. were set to meet emissions standards. Since you're not worried about that any more just set the timing to where the engine runs the way you like it to run. The specification is irrelevant now. You're on your own.

Did the engine get wet from the coolant that came from the radiator? Did you jostle any wires when you were changing the radiator? Or the hoses? Running good when cold, then bad when warm is a sign of a disconnected coolant temperature sensor. Check that first, maybe you'll be lucky. Make sure you didn't swap it with the thermotime switch. Download the Fuel Injection Guide and run the tests at the ECU connector if you don't find an easy fix.

Another thought that popped in to my head - the pressure inside the tank might contribute to the gassy smell by pushing fumes or liquid through any small leaks in the filler neck, in to the cabin. But the tank's outlet and return lines will see the same pressure. So it won't affect fuel pressure, since fuel pressure is between the pump and the regulator. Doubtful that you would have over 28-36 psi of tank pressure under the cap since that would blow the tank up like a balloon. Just saying, don't get distracted by the odd things. There's a spring-loaded relief valve in the vent line that holds a small amount of pressure before venting. And a valve in the cap to let air in if pressure goes negative. So, the gas heats up, pressure builds, the gas cools down, the cap lets it reload. Also, on fuel pressure - a clogged filter could lower flow and pressure. Another simple fix, but only need to look at it if the measured pressure is low.

Didn't mean to demean with the above post. But many many people have been here trying to solve their EFI problems and they always end up taking the measurements that need to be taken. There are so many interconnected pieces, and often someone will adjust one to try to help the problem (like your timing adjustment), and end up hiding the true cause. Volt/ohm meter, fuel pressure gauge, and timing light and you can get the engine to where it should run right. You might find something off on the way.

Some people say that a little bit of pressure is normal on the newer 280Z's, like yours. You're focusing on the simple obvious stuff though. Noises and smells. They won't tell you enough to solve the problem

Considering all, it really shouldn't be dying if it's the lean AFM problem. I've had that issue and the engine will sit and idle forever, and drive with the intake popping, but it doesn't sputter and die. It just won't accelerate. Even seven years ago the car was 30 years old. Could have a rusty tank, or even old fuel if you haven't been ablt to drive it enough to cycle through a tank. You need to confirm that you have good consistent fuel pressure. It's critical to the EFI system operation. Build the basic information, like fuel pressure, correct timing, intact cam lobes, notch - groove - timing mark aligned, etc. It might even be an ignition module problem. What does the tachometer do while it's popping and sputtering? It gets its signal from the coil, and gives clues about what's happening there. Gotta measure and record those basics though. Get them all in one place for a good review.

Have you had the valve cover off? Inspect the cam lobs and verify that the notch and groove match the zero mark on the pulley. When you can't find the simple solution you need to go back to the basics.

As Fastwoman has often noted, a lean miss will leave unburned fuel in the exhaust system. You have made no mention of driving the car (oops, sorry, you did mention driving in the post above. My mistake). No offense but that's what really matters. You don't want to decide that the engine needs rebuilding off of a vacuum gauge reading or some popping in the intake manifold. Not really clear what you're trying to do. Are you trying to make it sound good so that you can sell it, or does the popping just bother you when you start it to keep things lubricated? Kind of sounds like you're storing the car as a "survivor" type car. 7800 miles can be put on car in about 6 months, on average. You're obviously not using the car. The timing adjustment could probably cover a lean mixture. I'd put that coolant circuit tweak and see what happens. It only costs about $3 and some time, and is completely reversible. No wiring cutting needed.

If you download from the Downloads section (choice from the column on the upper left of this page) it will download as one big zip file that opens in to a folder of separate chapters. Super easy. 1972 is 74.5 MB total. You have to be logged in to download the FSM's.

There are several potential air leak paths in to the intake system, from split vacuum hoses, PCV hoses, the EGR tube, gaskets like site mentioned, and more. Could also be a low fuel pressure, as noted. But, considering that you've put seven years worth of work into it already, maybe the coolant temperature sensor circuit tweak would be worthwhile. It will allow you to add fuel to the fuel-air mixture and see if the popping is due to a lean mixture. Sometimes you can fix everything on the engine and still have a lean mixture, due to 39 year old old parts and/or today's fuel. http://atlanticz.ca/zclub/techtips/tempsensorpot/index.html Do not adjust your AFM.

Don't the pads eventually wear down to "normal" orientation? There seems to be something about the blend and design of parts on the Z's that lends itself to squeal. I threw away the shims on my Pathfinder front brakes years ago, by accident, and they've never squealed, even after the second set of shimless pads. But my Z brakes have always squealed, with three different brands of pads, and the aftermarket anti-squeal shims, and anti-squeal goop in a can sprayed n the backs, and high-temperature grease, etc. None of the tricks work, only the Nissan shims. Thanks for the suggestion though. Maybe some pad shaping with a grinder would help. Easier to just go with factory parts.

If you mean pressure leak-down, not external leak, the Aeromotive regulators all do that. They're not designed to hold pressure, only to regulate it during flow. Actually, from what I've read, pretty much all of the relatively inexpensive aluminum body adjustable regulators leak-down quickly. There are drawings on the last pages of the Engine Fuel chapter that show the plumbing of the factory FPR.

That does help. The pressure buildup in the tank and the symptoms you describe don't fit together though. Are you sure that it's pressure and not vacuum? Because the popping and dying could be caused by fuel starvation. But that wouldn't be caused by pressure in the tank. What's happens if you just let it run with the cap off? You didn't say anything about actually driving the car either. And 2008 was a long time ago. Have you been living with this for seven years? Also, "adjusting timing" doesn't tell where it ended up. What was the number? Sorry, but devil, details, all that stuff.

It actually sounds a little worse that plain old lean running from an AFM issue. Hate to say camshaft lobe but that's a possibility. You didn't give much information, like can the car be driven, is this a new problem, is this car new to you, stuff like that. That would help a lot. If it's a camshaft lobe it should go away when you disconnect that cylinder's injector. No more fuel to pop. Disconnect one injector at a time, rev it up and listen for the pop. If it's isolated to one cylinder you know where the problem is. The injector pug clips take some finesse to remove. The video was better, now tell a story about the car.