Zed Head

I like the points suggestion. Sounds like the OP really just needs to give it a good tune-up. That would cover points, condenser, valve lash, timing, etc.

Do you have some links, I'm searched out. The thing is, when it comes to boiling or vaporizing, the low boiling components go first. They don't wait for the high boiling components, if more high oilers are added. There's no averaging down. Fuel is a blend of vapor pressures.

Thanks. I couldn't find the actual reference to using diesel to change vapor pressure but I did find another article that kind of shows he's just a guy like us, pulling together odds and ends and making assumptions. http://fifthaveinternetgarage.com/pdf/RefiningModernGasoline.pdf " Ethanol alcohol attracts water. It picks up moisture throughout the fuel system. In the early gasohol era, this sensitivity to water led to problems because service stations often had water in the bottom of their underground tanks. Officially… the petroleum industry is well aware of these considerations and companies using ethanol have implemented procedures to eliminate moisture in underground storage tanks. It is best to check the fuel you buy to see for sure if there is water in your fuel, especially if you are going to place your antique vehicle in storage for longer than 60 days. The addition of 10% ethanol will typically contribute 2.5 or more octane numbers to the finished blend. The addition of ethanol increases vapor pressure by up to 1.0 psi although refiners may make other alterations to limit vapor pressure to comply with federal regulations. Ethanol is approximately 35% oxygen (which is part of the source of vapor lock when we use modern gasoline in our antique vehicles) so a 10% blend would contain approximately 3.5 weight percent (w%) oxygen that improves combustion properties. Ethanol is often confused with methanol. These two alcohols have distinctly different characteristics. Unlike ethanol, methanol is very toxic. Ethanol provides better water tolerance and better fuel system compatibility and contains less oxygen than methanol. Methanol causes a significant increase in volatility (which is why it is used in race cars and performance applications) while ethanol results in only a slight increase.

It might be gone by now, it's been a while. I meant to get out there but it was either too cold or too wet. Should be above water, it's on the high side, Row 18. Anybody recognize it? Posting mainly for the color. It's got one of those 2.7 liter engines. https://row52.com/Vehicle/Index/JN1HZ06S7BX403214 @Mark Maras

Is your throttle return spring intact? They rust and break. There's a second spring on the throttle body itself but it's not very strong.

77 still used the three part fuel rail, consider using a 78 or a ZX rail, or aluminum. Search "heat soak" and/or "hot start" problems before you get too far along. You might break some thermostat housing bolts also. They tend to rust in place and break in the middle though. Injector mount bolts break too. And exhaust pipe flange studs. Lots of breaking and stuckness. Check the manifold surfaces for flatness. Consider just having another complete engine ready to swap in. With a 5 speed. Just an option.

77 still used the three part fuel rail, consider using a 78 or a ZX rail, or aluminum. Search "heat soak" and/or "hot start" problems before you get too far along. You might break some thermostat housing bolts also. They tend to rust in place and break in the middle though. Injector mount bolts break too. And exhaust pipe flange studs. Lots of breaking and stuckness. Check the manifold surfaces for flatness. Consider just having another complete engine ready to swap in. With a 5 speed. Just an option.

I've had a similar thought but with regard to detonation. Another plus would be more energy per unit volume. Seems like the pros would have had to think of it. One downside I would guess is that diesel needs high pressures to burn fully, I think. CR's on diesel engines are much higher than gasoline. Probably would dirty the plugs a lot faster. And smell bad. I'm not sure the idea pans out fully though. The high vapor pressure components are still in the formulation and they would "distill" or "fractionate" out. The fuel is a blend of molecules, so all you'd really end up with is a lower concentration of the unwanted molecules, but they'd still bubble and boil. It might be the same for my detonation argument. It makes sense from an "averaging out" view, but I don't think that's how the fuel works. An easy experiment though. Do you have a name or author for the article?

She has the problem of sporadicity. Checking for spark works when the engine won't start, but won't really help when she's rumbling down the road. Always good to have a plan of action in place though, for when the problem happens. And it's the rumbling that makes things not so clear. The engine is running, just not well. That's where a wire wiggle might show something.

Saw your post on another forum and thought of something that might make it easier to actually do something. You can leave the metal fuel rail in place and just disconnect it, running a rubber hose to replace its function. If it has a positive effect then you can decide whether or not to remove the metal rail. All you need is some hose and a screwdriver for the hose clamps. No need to unbolt anything anything, just pull a hose end off and replace it with another hose.

Just trying to help. Honest. I see the tape now, but I'd take the flares off and show the car without them. I'd show the passenger side of the car also, I always get suspicious when parts of the car aren't shown. Might as well post the eBay link too. Is the big red dot a decal? I'd take the decals off. No offense, I know you're really showing your vision for the car, but buyers would rather see a clean slate. Looks like a decent car.

The running rich (black plugs) and the sudden dying are typical signs of a bad ECU OR a bad ECU connection. People have reported wiggling the ECU connector while driving to fix it. Maybe the fix of replacing the ECU really just fixed the connector issue. And it's come back. Might try wiggling the ECU connector, or pulling it off and putting it back on, just to see if it has an effect. The rumbling might just be the engine loading up with fuel and fouling a few plugs. Running on fewer cylinders for a while. If wiggling the connector has an effect I'm not really sure what the long-term solution is. But it would be a clue. Could also be that a second ECU has gone bad.

Can you give more detail on the "rumble" noise? I got: a rumbling noise, a lack of power under load, and sudden engine dying, as the three main symptoms. Have you checked the air filter and housing? Maybe a rodent moved in. I've seen 'em do it. It's a great home, with a private entrance. Wasn't the engine suddenly dying one of the original problems?

I probably wasn't very clear in what I meant. I think that there are other ways to tell if you have a regulated or non-regulated alternator, without taking it apart. The marks on the outside of the case, or the shape of the case, or even just measuring what the wires supply. You can easily supply a new "S" wire with a jumper directly to the battery positive. Just for a test. Most melted wires are caused by battery amperage (edit - had voltage), not alternator. The battery is a huge reservoir of amps waiting to get out and cause damage.

Nada for moi?

Woops. I've seen 86 referred to before. I don't know if people found them in 86 cars before Nissan documented it, or if it's an error. I still look under the 86 cars just to be sure.

I saw the comment about you in the other thread and thought "what compelled him (the commenter) to make that comment, in that manner, referring to grannyknot?" It was completely unnecessary to his point to include you in his comment. Plus, he must know he wasn't welcome in the thread. It was flowing nicely. The internet is a strange place, full of strange people. Edit - tried to find the comment but can't. Maybe Mike got rid of it. Good...

Sorry to destroy your joy. Don't take this wrong, but I think that your energy might be misdirected. There are other, easier, ways to determine if your alternator is internally regulated. Also, easy ways to determine if a shorted wire caused the melt. Love the effort, just might benefit from being repointed. I do have my own disassembled alternator in the garage though, and an old thread describing how I was looking at the wrong diodes. I was on your path. That memory led me to the Rockauto picture. I have a replacement regulator (like the picture but just the regulator) in my garage (they're cheap), that I never installed because that wasn't the problem.

Good point. He must have confused his turbos. And missed a year. Nissan only used the CLSD in the 86-89 300ZX turbo cars. Not the 280ZX turbos. The other somewhat popular option is the OBX diff. It's a knockoff though and takes some extra work to get working properly.

Whoa.... I broke a sweat just reading those two posts. And we're in the middle of an ice-storm. He could also just carry a can of starting fluid.

Since you don't know the history, and it doesn't run well enough to tune, your best path is to verify that the various rotating parts are timed correctly. Hatepotholez is going through the same situation and just found that his damper pulley might have slipped, for example. I would start with the ignition timing mark on the damper pulley at zero and verify that the cam shaft is in the proper orientation, the rotor in the distributor is pointing at the correct electrode, and the plug wires are properly placed. 1-5-3-6-2-4, counterclockwise, like site's picture. Then rotate the engine by hand and check valve lash, correcting any that are off. The older engines are known for worn valve seats due to unleaded fuel. That could cause some backfires, or popping back through the intake (some people call that front-fire, I think). They're also known for throwing lash pads, which would cause the valve not to open fully. Anyway, you've spent enough time on it to justify starting from zero. Set all of those things once, and you won't have to wonder about them.

Try to get more methodical. I don't see valve lash adjustment on your list. That's the first item in the later years Engine Tune Up chapters. Borrow a timing light and actually set the timing to where it should be so that you don't fix the problem but still have the symptoms because the timing is wrong. Use a meter and measure voltage at the ballast. Measure resistance of the resistor. Find out what the other end of that hose was connected to. Better to know than guess. Seriously.

He's just asking how to be sure the pump will supply his carbs so that his engine will start and run. Once the carb's float bowls get filled after the first start it will probably be fine. It will start on float bowl fuel. BUT, study the FSM description closely again. Usually Nissan bypassed the RPM or oil pressure or AFM (for EFI engines) control when the key is at Start. So there might not actually be a problem. SteveJ is a 260Z guy. He might know. @SteveJ.

There's a guy on Hybridz who had a torsen-type diff made for the R200 case. Search "mfactory lsd" over there. It was a group buy last time I saw it.

What does tl dr mean again? I always forget. I think it would be on the other side. Compare the curve on the brushes.