Zed Head

What kind of voltmeter are you using? Sounds like an old analog meter that hasn't been zeroed or is just no good. Or a digital meter on the wrong setting. Measure voltage at the battery with the key off. Better yet, measure voltage at the battery on a car that is working properly. Post a picture of your meter as you've been using it.

There was a whole long thread on this topic about one or two weeks ago. You can probably find it. The best solution seemed to be to bend the lever.

Your problem is kind of bizarre. But I still think that my original suggestion is worth trying. It won't hurt anything. "New electronics expect nice clean electrical supply. A capacitor on the power line might help." Try a capacitor that would normally be used on the alternator power line. Or, first, check that you have a capacitor on the alternator power line. Maybe someone left it off. It's the round cylinder on the back of the alternator, about the size of a stack of 15 dimes or so.

Don't forget the transmission mount either. There are three points of contact, all rubber mounted, unless you have an early mount.

In that case, this might be a better solution - http://forums.hybridz.org/index.php/topic/34969-cv-adapter-print/page__p__452891__hl__%2Badapter+%2Bdrawing__fromsearch__1#entry452891 I have a set of CV shafts and actually have one adapter half done. But I'm just doing it for fun and and as a future alternative if my half-shafts wear out. They don't offer a whole lot over the u-joint half-shafts. Here's another link to an adapter for the 4 bolt 300Zx turbo CVs - http://forums.hybridz.org/index.php/topic/103581-billet-z31-cvcompanion-flange-adaptors/ And one more vendor, for the 6 bolt style that you have - http://www.modern-motorsports.com/catalog/product_info.php?products_id=63&PHPSESSID=51477db1b430e29534a8802dfd4401cd The last link is notorious for slow replies though, unless you create an account, communicate through it and get lucky. Edit - Also, I can't find any evidence that the turbo CV shaft is any different than the NA CV shaft. The MM site implies that it is, but if you go to an auto parts store they'll sell you the same part for either car.

Just realized a while ago that my suggestion was about the reset cable, but your problem is with recording miles. zbane's probably got the best suggestion.

This might help - http://atlanticz.ca/zclub/techtips/alternatorswap/index.html I recommend jumping the wires at the connector instead of cutting them. It's easier and cleaner and reversible, if you decided to go back to an external in the future.

The ignition module is a very expensive thing to replace for no firm reason. You might just have electrical noise messing with your radio. New electronics expect nice clean electrical supply. A capacitor on the power line might help. But a check of the supply voltage would be the first thing to do as 5th suggests. Your alternator might be dying.

Could be a bad strut, or a loose strut mounting point, or a loose gland nut. A broken motor mount will also feel like something broken in the back.

I think that you have things backwards. The 77 came with stub axles in the diff, which would then bolt to half-shafts with u-joints. The 83 probably came with CV shafts, which are a complete assembly from diff to wheel hub flange. Drawings in the FSM or descriptions around the internet. The CV shafts would require an adapter and are probably not worth the trouble for a stock turbo motor.

The 77 came with an R200. If the 83 did also, they will look identical. The 83 might have CV shafts, which will pop out. The 77 R200 has stub axles, which will pop out and pop right into the 83 diff, if it's an R200. The back diff mount will need removing from the 83 so that the mustache bar can be bolted on. If the 83 has an R180, then more work will be involved. I would get the FSMs for 77 and 83 and look through the Prop and Diff sections to see what you have and how the parts fit. Edit - just noticed the T. If it's a turbo then it should be an R200, I believe. It should be an easy bolt-in swap. The 83 might be a Limited Slip Differential also, which would be nice (I don't know if all 83 turbos came with an LSD or not).

I think that there might be a window of time where the WTS gets extra hot while the heat is equilibrating. That might be why the problem only occurs at ~15 -20 minutes after shut-down. Before then, the hot spot hasn't reached the WTS, after then, the heat has spread. The water temperature gauge is right next to it and shows as very hot whenever the problem occurs. You're right, it could be that the entire engine has extra heat and it doesn't matter where the WTS is. But the exhaust manifold is right next to the housing and has lots of mass and no cooling. It's a theory, just needs more data. Wish I had more equipment. I did see in the FSM that Nissan explains the ZX cooling fans purpose as for cooling the fuel in the injectors and the fuel hoses. Which implies that they identified hot injectors and fuel as a problem. Maybe it would pay to put a timer on the fuel pump... Anything but the giant fan and air manifold hanging over the engine. You should have a small water line running from the thermostat housing through an aluminum block under the AAR and then back down to a T in the return line from the heater core, by the water pump. It gets the AAR up to water temperature sooner, I assume, since it sits on the intake manifold, which would be cooled by flowing air while the engine is running. Still haven't figured out how people live in Canada. Seems like one winter would be enough. No offense!

The CSV only gets power when the Start circuit is active. Measuring fuel pressure is not difficult and you'll save yourself a lot of time by just getting the gauge and doing it. But, on the other hand, looking at all of the stuff that's not the problem is pretty educational. If you had a CTS issue it would be manifested after starting also. Good luck.

I interpreted "sensor" as CSV, not thermotime switch. It's a thermal switch, not so much a sensor. Oops. I was just messing with a CVS last night, with an ohm-meter and a heat gun. It went from ~ 64 ohms cold, to open circuit hot. The resistance is from a heating element in the switch, like the same in the AAR. Most AARs measure ~ 60 ohms also. The switch is designed to get hot when the starter circuit is active so that you don't flood a cold engine. There's not much to it, the CSV solenoid does not need a lot of current to move. Testing requires a pressure gauge between the rail and the filter. Measure pressure, start the engine, then monitor pressure after shutting the engine off, and right before attempting to start. The regulators do get old and the seats don't seal. I have a few in my garage that regulate fine but don't hold pressure.

You might be losing fuel pressure when the pump is off. Could be the FPR or the check valve in the fuel pump. The cold start valve is probably fine. You can check it's operation by jumping the connector pins with a nine volt battery. That's a fine line between 55 and 58, and that spec is for the thermotime switch. Which could also be bad or have a bad connection. Current for the CSV runs through the thermotime switch. I would check fuel pressure first. At 55 degrees the engine should still stat pretty easily. Mine does, since I got an FPR that holds pressure, and I do not have a CSV.

Good luck! It's a tiny hole and getting the tiny screw in to it requires making your hands tiny to squeeze in to the tiny space available. But before you loosen anything up: if you can turn the reset knob around rapidly and get good movement from the numbers, its probably set correctly. If you give the knob a quick twist and the numbers don't keep up, it's probably out.

It's been proposed that having the intake side port slightly smaller than the head port provides some anti-reversion benefits. Keeps the charge from coming back out of the hole. From what I've read, the real restriction to flow is inside the head, so it might not offer any benefits. Lots of good reading over on Hybridz.org. Look for BRAAP's postings. It's not really clear what you're showing in your picture (to me anyway). How did you determine that there was a mismatch?

It's just my attempt to reason out where the extra heat comes from. When the engine is running and water is flowing, the heat is transferred to the water to the radiator to the air flowing by. When you turn off the engine, everything close to the water is at the temperature shown on the gauge. So where does the extra heat come from? It must be a large mass that is hotter than the water, since it is conducting in to everything around it. Anyway, that's my reasoning, plus the fact that Nissan put some effort in to moving the sensor. I wish one of the Nissan engineers would write his memoirs and expose the secrets from inside the company. My new goose chase is to T in an auxiliary electric water pump on the AAR pad heating line. This will move hot water from the T stat housing to the lower intake hose. Bimmers, Audis, VWs, even the odd Dodge Durango have them. But, similar to some Z things, no one is really sure why they are there. By the way, I had another hot start issue today, and twisting that potentiometer knob did the trick again. The reasoning may be off but the results are real. This should be a solvable problem...

Captain, I also pondered a switch, or moving the WTS (aka CTS), along with some other possibilities, but realized that I didn't know anything yet, hence the Radio Shack quick kludge. So for ~$4 and some time I learned something. Putting it out here so, maybe, someone else can generate some results or at least stop the aggravation for a while. The WTS theory could be rejected or supported by anyone with a P79 head, with a working CHTS instead of WTS. The CHTS shouldn't feel the residual heat of the exhaust manifold on the other side of the engine. I also have an F54/P79 engine in the garage that might get installed eventually. Good luck to all that suffer with it. I have an extra WTS that I might install somewhere else (maybe in a core plug to a water passage or that drain plug on the block) and switch in to the circuit. It's my rolling Nissan EFI theory laboratory.

The stock tach uses the blue wire from coil negative. Won't that one work? Not sure what you mean by "pulsed negative". Why do you think that pin 4 would work?

Almost as good - http://www.carpartsmanual.com/datsunS30/DatsunZIndex/Body260Z280Z/2Seater/DoorMouldingFinisherArmRestMirror/tabid/1794/Default.aspx

Have you had the cable off of the back of the odometer before? It's possible to tighten the tiny screw down enough to make the odometer work sometimes, but without the screw actually being seated in the tiny hole. I had a similar problem,where I couldn't reset the odometer, it just slipped. Once I got the screw seated correctly, it worked fine.

My car's had the hot start stumbling problem more often recently so I decided to try something. In my case, the problem seems like a lean condition, based on the intake backfires and the lack of gasoline smell or smoke in the exhaust. I also noticed that if the temperature gauge went higher than usual, like up to the middle of the M, that the problem was likely to happen. So I bought a 5 kohm Audio Taper Potentiometer and spliced it in to the water temperature circuit as a rheostat (two wires connected, one left open). Mounted it by the hood release handle in the cabin so that I could tune it when needed. It's basically the part behind the volume knob on an amplifier. The linear taper potentiometer changed resistance too fast (I had my ohm-meter in the Radio Shack store). It can only be used to add resistance so will only add more fuel. When the engine is running normally, I can't turn the knob, increasing the resistance, at all without the RPM dropping as the injectors stay open longer. But today I had two "hot start" cases where turning it stopped the stumbling and smoothed the running. I still had to wait about 15 seconds before I could take off, but it seemed to clear up faster, probably because the water pump was pumping more water, cooling the WTS down to true engine temperature. Plus, at least it was running well, instead of jerking and popping. My current theory is that the WTS overheats due to residual heat from the exhaust manifold (the only engine part that doesn't really get cooled by the radiator coolant) indicating a hotter engine, needing less gas. This may be why Nissan moved the sensor to the other side of the head on the P79 head. It's just a guess. Maybe the injectors also get hot or maybe it's just hot injectors and adding fuel still helps. Who knows. It really seems to work though. It's worth a shot if anyone else wants to try it.

You might explain to him that he already has electronic ignition. Maybe he thinks that he has a 240Z, which came with points. The "lite" in Unilite mean optical I believe. Unilite - optical, Crane XR3000 - optical, Nissan 1975 280Z, variable reluctor. All three are electronic. They'll all do the job, but not together. You'll still have to disconnect the factory unit, since it will still be running current through the coil if you don't.

Your customer does not know what he's asking, I think. But, of course, he's right. If you don't unplug the factory module, the circuit doesn't break and you won't get spark. Just unplug it, it is a branch off of the blue wire. The ECU and the tach need the blue wire to be connected to the coil - terminal. No, the module is in the passenger kick panel area. You should download the FSM and read the Electrical section. The factory ballast has two resistive circuits, one low for starting and one high for running. If you just have two then you'll need to run the starting circuit and the running circuit both to one side and the output to the coil + from the other end. The smoke means that the resistor is getting hot because there's a short on the coil side, which might mean that the module wire is not corrected properly. The module is the "breaker" part of the spark circuit. Sounds like your circuit is always "made".