Daniel

Dave is correct clean is best. That said,let the car idle and press and play with the linkage parts to try and find the problem. Press on each carb return. It may be one weak spring. It's easy to tighten them .Just remove one end and turn it a couple of revolutions and replace it(without it unwinding). That's where I would start first. Did you clean the carb tops so the carbon/residue would not make them hang?

The obvious reason for the melt down is a short/and or poor connection. The location of course is the issue. First keep in mind one of those wires from the starter was a fuseable link. It should not be replaced with any thing but that. My first area of inspection would be the harness under the battery. Years of acid drip may have taken their toll.Just because the tape may look good,who knows what someone did once upon a time. Next would be to start an inspection of connectors. That hot should be very visable. If not undo them one a time till you find it. Odds favor the trouble being where hands have touched it . Not in the wire itself. Except for the acid area.

I think there were two sizes of those insulators .The thick being about the thickness of an ice cream sandwich.As for a temp.fix on the cooling system---O.k. --I would have said crazy, no way, until now having seen it holding for over 2months on a friends car.--Ready???? Put 2 tablespoons of black pepper in the radiator. It doesn't hurt anything and as long as the leak is not too large it will stop it. Let me know.

Fuel smell is one thing. The exhaust smell can be various things. On mine it was an adjustment of the latch on the rearhatch. It didn't take me but about 5 years to find that:stupid: Now that it closes tight no problem. Oh I found those rubber magnets like the ones you get from the pizza place for you frig. work great for closing those floor holes.

Pardon my frankness but it sounds like you want a quick fix for a $950.00 car. The odds are against that. If you go out and buy new carbs and new elec. dist. you are just throwing parts at it in search of a fix. I would suggest get the old car running in best old car performance before you take a chance of adding problems when putting new parts in. Get a good starting reference point.

I agree the overflows need to go somewhere to get them away from draining on top of the exhaust. When they do drain ,which is only when something is wrong (mine once in my life)they just run the fuel to the aircleaner and it runs out the bottom. That is not your fuel smell. As I say the factory correct from what you have would be a length of hose to the air cleaner. That would not change the smell factor. You need to look somewhere else.

Some things to think about. The reason you dim at idle is the rpms are so low the alt output is minimal. In an effort to find the answer to that 240 quirk I have come up witha few things that sound good in theory only. 1) change the pully size on the alt making it spin faster at idle. NO, that will pull the car idle down as the alt. is like a clutch on a go-cart. The more rpms the magnetic field increases so does the alt resistence. 2)Ok then turn up the idle to compensate for the alt resistance. NO, With the resistance already there when you increase rpm's more force is put on the fan belt. Causing it to break, slip or burn. I'm still working number 3. Keep in mind that 90a is only charging the battery at the proper rpm's. At idle my guess it is very close to stock(minimum output if any) The difference between 60a and 90a charge is time to return the battery to full charge.12v is 12v

Is this a common thing? Things like pulley size and rpm operating range matter to the performance of your car and charging system. Is your Z so heavy laden with electrics that it needs the 90a charge?

Square header , Round gasket. I brought that up just so you would not start the job and go"well damn' Great Bargain! It'll be sweet!

The ballast resistor seems to be the new carb. Meaning it gets a lot of blame it doesn't deserve. If it was bad the car would run with the key in start mode and die when released. Its just a strip of metal. You can jump across it as a test.

You may wish to start by pulling the valve cover and make sure you dont have a stuck valve or loose rocker arm. That could cause the "0" also. Then maybe just retorqueing the head to its proper values as a test.

I think "getting hard to find" is an understatement. I saw one and had to have it at a Z show in the mid 1990's. At that time I worked for AT&T so I got free long distance calls. I spent about three days calling around the U.S. Finally found it in seattle wash. I think Ipaid $100.00 +/- at that time.

Should have told the cops that the rover was full of doughnuts!!!

This post seems to have hit at a perfect time. I visited with a friend yesterday that is a nissian tech.He had just returned from brake school. Per his instructor the silicone is for race cars only. The high temp makes it good for that purpose. The fact it doesn't mix with water does not mean there will be no water in the brake system. It should be changed at a minimum once a year. It will destroy the metal in the brake system with pits and scars and cause premature failure of rubber parts. It has no reason to be in a street vehicle. I guess once again.If you thought you out thought Datsun,you better think again!!

No doubt the plugs are fouled now. The carb adjust always is the last step of a process.Points and plugs clean and correct ,valves set correct,Timing, and clean pistons in the carb tops. When all those are "yes" then the carb adjust will really bring the car to life. If you have done these things and still cant get idle you may adjust one of the idle screws on the carb to get the car to stay alive long enough to work on it. You may have a vaccum or air leak problem on the intake. Check your hoses for cracks.

As promised this is a paste from the Peak antifreeze webpage. Water is an excellent conductor of heat. Glycols are not as good of heat conductors as water. As the concentration of glycol increases, the heat transfer ability of the mixture decreases. This change in heat transfer is not a problem. During engine and cooling system design the heat transfer ability of the coolant is taken into effect. What is important is not using a fluid that is outside the cooling system design parameters. Modern engines are designed to run with a glycol - water blend between 40% and 60% glycol. Using a coolant outside these limits will cause the engine to run at the wrong temperature. This change sacrifices engine performance and leads to other problems. The second function of an antifreeze is to protect the metals in a vehicle's cooling system from corrosion. Antifreeze is able to perform this function by the addition of inhibitors. Inhibitor types vary depending on the type of antifreeze. Inhibitors can be of many different forms including organic and inorganic chemicals. One thing that is common with all inhibitors is that they are designed to work in a water solution. The addition of water "activates" the inhibitors, allowing them to protect the metals. For this reason it is important to always mix antifreeze with water in a vehicle’s cooling system. As the name implies the third main function of antifreeze is to protect the cooling system from freezing. The way to achieve maximum freeze protection differs between ethylene and propylene glycol. For ethylene glycol the maximum protection is at 67% ethylene glycol in water. A ethylene glycol solution of this concentration will freeze at -84° F (pure ethylene glycol freezes at 8° F). Propylene glycol does not freeze. It experiences a chemical phenomenon known as supercooling. For this reason there is no freezing point of pure PG. Due to the heat transfer and inhibitor activation reasons discussed above, PG antifreeze should also be maintained between 40% and 70% in water. Boil over protection with both glycols increases with glycol concentration.

My point is that antifreeze is not any kind of shield (to heat), it does not keep "hot" from metal---**EDIT Actually in that antifreeze/water mix is less efficient at removing heat, it is a shield;----- Why Gee Carl you've covered all the bases tonite huh???? (sorry i couldn't help it):stupid:

Mark, This is not a challenge, as I say its a yearly topic. Please note my edit of the previous post. I'm glad you find this interesting!

Carl, Its not an absolute shield, no more than your sweater is an absolute shield from the cold. As for you non-believers about the pure antifreeze freezing before a 50/50 mix I will repost this becoming annual post in the morning(notice Carl didn't question that ?---this year !) This is a paste from PEAK website. A. Why is it important to mix antifreeze with water? Antifreeze contains chemicals that protect your engine against rust and corrosion, as well as freeze-up and boil over protection. Water is required to activate the chemicals in the inhibitor package. Furthermore, adding water to antifreeze actually increases the freeze-up and boil over protection provided. For example, a mix of 40% antifreeze and 60% water provides freeze-up protection down to -10°F and boil over protection up to 259°F. In comparison, a mix of 70% antifreeze and 30% water provides freeze-up protection down to -62°F and boil over protection up to 270°F. However, we do not recommend adding more than 70% antifreeze. This would limit the corrosion and freeze up protection and heat transfer capabilities of the antifreeze. .

Since all the worst has been covered,How 'bout some basics. Make sure the fan belt is tight and not worn. Remember when forcing air thru the radiator( MOVING),the fan and water pump are not at maximum demand. Next is the status of your antifreeze.A 50/50 mix is optimum. Pure antifreeze will freeze before a 50% water mix. The over heat will occur when the "antifreeze" breaks down.It is coolant. Each time your car hits normal temp the "antifreeze" form a protective sleeve in your engine to keep the hot from the metal. When the car cools the "platelets" release growing less sticky each time. Soon they don't bond at temp anymore. Theory has it if you never let your car cool down,Your coolant would never wear out as its the hot/cool change that kills it.

Thanks ,Good info. A couple of questions. Am I to assume the t5 will go into a 72/73 without those issues? Also you said stock clutch.Was that stock for a 240 or stock for a t5.The pilot bushing size did not change? Thanks. your work looks good!

I do not say this to hurt you, but just as this is something that we all learn about Z cars. Its damn hard to beat those that designed it. If you think you are sure you are going to "out clever" them you better think again real hard.

I like this multiple choice repairLOL . I pick #2. Throttle cleaner and a toothbrush.(residue build up).Common problem.

My first choice is socket. They have springs in them that hold the contact against the bulb.They get tired or rusted.Sometimes stretching them will work. Use a test light to begin with and see if there is power.

Common problem, Your switch is burned out. Easy fix.There are threads with photos and part numbers for 240z