Zed Head

I think that they must add some butane or pentane so that intake vacuum will cause it to foam. So it probably does foam up and get the solvent in to areas it might not otherwise reach. But it won't dissolve the typical hard carbon deposits in an intake runner or back of a valve, I think. Somebody wrote about that somewhere out on the internet. You just end up with clean carbon deposits.

That's the image they've created. But run the stuff through a freshly rebuilt engine you'll probably get just as much smoke. Check the SDS - http://seafoamsales.com/wp-content/uploads/2017/01/Sea-Foam-Motor-Treatment-SDS-v20161205-ENG.pdf "Hydrocarbons" come from oil, anything/everything from methane to diesel could be in there. But they're all just crude oil fractions. A bottle of rubbing alcohol and a gallon of paint thinner and you might have the same blend. http://www.gcelectronics.com/order/msds/226.pdf

If you can, stick your meter probes through the back of the T plug, or pull the T plug partially off, and measure voltage at the S pin (can't remember if it's the vertical or the horizontal of the T). Dave's adapter works on the assumption that the wires from the external VR are correct. Sounds like you're missing the S connection. S should connect to the battery positive circuit. If you don't know which is S, measure both with the key at Run. They should both show battery voltage then.

Here's a good one.

The narrower range would be a sign of a belt slipping less. The thing about the ammeter is that it shows whether the battery or the alternator is supplying the current so can have a large swing as it goes negative or positive. A voltmeter will always sit around 12.6 and the same current direction change will only cause a fraction of a volt movement on the meter. Plus any "wild" movement of a gauge is a sign that the needle damping mechanism is damaged. You can buy spray-on belt dressing for a few dollars. But any squeaking of the belt is bad. Once they start slipping the surface overheats and the rubber hardens. Then they slip more.

Some of the prices seem reasonable. $45 for an ammeter'fuel gauge, not bad if it works. Fun to browse through and look for interesting errors.

No problem, I learned something about my own parking brake. A good puzzle. Check that Body Electrical chapter for the dome light circuit. Pretty sure I flipped by it on the way to the parking brake light page. I think that it might be similar to the e-brake with several possible ground circuits. You can push the door button with your finger though, easy check. Start a new thread for LED's. There are some guys here who know quite a bit about them. I don't know much.

That's the way to do it. But keep your eyes open for a cheap ECU. Most of us out here have a spare or two because the old electronics generally seem to be drying out and dying. Ignition modules and ECU's. I had a bad ECU myself and it was supposed to be a spare. A few others have had bad ECU's over the years. And they tend to flood out as part of the dying process.

That sounds right, except for the rapid leak-down after shutoff, which is really just an inconvenience. The numbers, 37 and 35 and 30, for the conditions you described, all look about right.

I think that you might be right. I just went and looked at my 76 and I can see the GY wire coming from what looks like under the passenger seat and connecting to a black wire via a bullet connector. The way to test the black wire would be with a meter or a continuity checker. You'll get continuity to ground when the lever is up, and the circuit will open when the lever is down. That would show that it's a path to ground controlled by the lever position,which is how the system functions.

A thermostat that's stuck open will behave this way. Coolant flow isn't controlled so overcooling happens at freeway speeds. But it wouldn't cause temperature to go high. Not enough air flow would though. So a stuck open thermostat and poor air flow kind of fits the symptoms. The thermostat STOPS flow it doesn't cause it. The thermostat is there to increase engine temperature. People get that backward often. So the signs actually show that the thermostat might not be working properly. If the head gasket is bad it will typically overpressurize the system, from leaking exhaust gases, causing fluid loss. If it's an air flow issue, opening the hood typically has an effect. Here's something that I don't think was mentioned - is your heater core bypassed? That can cause overheating by lowering the coolant flow through the block and head.

There was a guy a few years ago who put a P90 on dished pistons just so that he could sell the car. We told him about the CR but he did it anyway. Still wondering who ended up with that car.

2-4-6 Blue brings up a good point about the head gasket and the timing. Could be that you really have a blown head gasket causing your problems.

I'd go with a shroud also. If the car is lowered and/or has an air dam in front the fan might not be pulling air through the radiator, just spinning it around behind it. Nissan built those shrouds for cars with AC because the fans can only move so much air without them. You might also go back to a stock radiator. Your engine is mild and doesn't really need what you have. I have an OReilly cheapo radiator and a shroud and I have zero cooling problems even on the hottest days. By the way, N47 is a stock 77-78 280Z head, not ZX Turbo. You have a plain old 77-78 NA engine at this point. Should be easy to cool.

It's not really a "pig tail", it's a length of wire that comes from the connector by the fuse box. It could either run down the door under the carpet and across to the switch, or across the dash and through the console to the switch. But it will be just a wire in a bundle of other wires. C-6 is in the junction block by the fuse panel. Here's a link to the factory FSM. Body Electrical chapter, Meters and Gauges has the diagrams. http://www.classiczcars.com/files/category/13-280z/

Yes, it does. Is there a problem? Not really clear why there's a question, no offense. Edit - looks like there's a fuse...

I changed my vote. Much depends on how fast the meter reacts, and how well damped the needle is, among other things. I overlooked the basic "changed something and it got better" description. That's the major clue, I think.

That's a pretty good clue except for "fluctuation". Can't tell if it's banging off the stops or jiittering 1 mm around the center. If it definitely got better when you tightened the belt, I'd tighten the belt again and see if it gets better again. I just made a comment based on average behavior but if your belt is oiled up or glazed maybe it is the cause. No matter what though, it sounds like you need a new belt. Get rid of that weakness and you'll know if it's the problem or not. "it is worn and now slipping all the time." The ammeter just shows charging or discharging, and rate of each. So, adding numbers from the gauge to the description would help a lot. And if the battery is fully charged or partially charged. That will affect how much the belt slips. So, just letting the battery drain down will make the problem worse.

Have a torch handy to heat up the casting. Mine wouldn't budge unless it was hot. When it cooled it stopped budging too.

Not clear that you put a nut on that eyelet and tightened it. Is that picture a representation, or your actual alternator? Where's the picture of the adapter plugged in? A loose belt usually just makes noise. I would disagree that it causes erratic charging. (Edit - changing my vote to Maybe).

The wiring will melt before the relay. The VR sensors can generate high voltage at high RPM, so sparking to a ground point might be a concern. But heat from current is probably not since there's essentially no current flow. Look at the connection terminal for the distributor wires, on the fenderwell, and you'll see that the wires are small gauge but the terminals are well separated and kept dry. Might be focused on the wrong thing.

Any loose container in the back will fly around the cabin in an accident. Hope you're not driving the car with a loose container of stuff back there.

It's the way the number 6 looks. 240Z and 280Z just look cooler than 260Z. Imagine if GM had produced a Z26 Camaro. Just not the same as Z28.

If it's that close you might try some of that cooling spray that people use for other problems. Or just a bag of ice on the spindle. I wouldn't go too crazy on using a temperature mismatch though because you don't want it stuck permanently. Or you could use a heat gun on the bearing. Don't get it too hot and the heat gun should let it come back off also. Heat will expand a hole pretty dramatically, I'd bet it will slide on pretty easily with not much heat. But if there's an auto parts store close by you could just go get another set. The next set will be probably be on the big side of the manufacturing tolerance range.

Did the original hood fit right? Why are you replacing it? Did the original hood have work done to it, like body filler or bending? Looks more like your body doesn't fit the hood.