NewZed

Pretty sure (I hope) that we've been discussing EFI. Your 260Z carbs are a different scenario, I believe. Your 280Z's are interesting. Are they still EFI and do you have any details on the injectors, insulators, etc.? In all of the discussion, the mechanism of what actually happens hasn't been clearly defined. You're down in the DOE's national lab zone, maybe they get better gas. The thermostats have the temperature rating stamped on them, I think, along with the part number. If you ever get a look, post the numbers please, it will be one or two more data points.

I have to disagree with this statement. Units are irrelevant, they describe the same reality. It seems like the essence of what you're saying is that the purpose of the three choices of thermostat is to keep the oil above a certain operating temperature. Apparently, because radiative cooling from the block and the oil pan overpower the control by the coolant circulation and radiator, keeping heat in the block maintains oil temperature. Therefore, once you're above that temperature your next worry is overheating. Makes sense since the thermostat is really a heat-retaining device, not a coolant flow inducing device. The anecdotes from KTM and Grape Ape are interesting but, in my case, here in Oregon, I have zero over-heating problems. I just got stuck in 3 mph, stop/go traffic out here on a hot afternoon in the sun for 40 minutes and thought for sure that I would see a sign of overheating if I was ever going to, at least the Temp needle creeping a little higher. It didn't budge. I don't have overheating problems, no signs of nucleate boiling, no overflowing coolant reservoirs, burping or bubbling from the over-flow tube, none of that. Signs are that I don't even get any in- or out-flow from the reservoir (I've checked), expansion and contraction of the fluid seem to be taken up by the flexibility of the hoses. My cooling system seems to work perfectly in removing heat. I've checked my thermostat housing with an IR gun and my thermostat seems to work perfectly in retaining heat. So my only reason to go to a 72 degree thermostat would be to stop the heat soak problem. My system meets all other design requirements, oil is hot, engine stays cool. So I'm still at the question of what is the best temperature to run my engine? Since I like performance - both on the high end, raw power, and the basics like a smooth idle, clean-smelling exhaust, crisp engine performance - I would make a change for things like that. I don't see any evidence that the 72 thermostat will offer that. And I am sitting right where the Nissan engineers intended me to be, by their own instructions in the FSM. At this point though, I would make the change just to see what happens, but Nissan (Courtesy Parts in this case) doesn't appear to stock them anymore. They have the other two, by part number, but not the Tropical. I don't like the aftermarket alternatives and that would be mixing variables anyway, so I'm stuck until I find an OEM Tropical thermostat. Hopefully I'll find a decent source, and can take a look at any performance effects (tiny of course, from a HybridZ perspective) of running 72 versus 82. It will still be anecdotal, based on how things feel and sound, but worth a look. Where's the OP? He should have something to say by now... Edit - apparently the Nissan L6 Tropical thermostat part number has been superceded to 21200-F3160, for any future readers. Shows up as a 1984.5 Pulsar NX part on the interweb, but the dimensions must be right. Has 160 in the part number so the odds are decent.

Seems like we're just looking at two different ways to keep whatever fuel system component it is that matters from getting too hot. One is to run a cold engine (160 thermostat) so that residual heat doesn't transfer in to that component. The other is to remove the heat from the component (via the fan) as it is transferred in, before the component reaches the critical temperature that cause the "heat soak" problem. In choosing between the two you have to decide if running your engine at a cooler than design temperature all of the time is what you want to do to avoid 20 seconds of extreme aggravation. Or if having a two pound electrical/mechanical band-aid is the way to go so that you can run your engine at design temperature (assuming that 180 is design, and 160 is not. If 160 is design, then going to a 160 thermostat is obvious). Aside from proving points with data (if I had the cash flow I would have a scanner and simple data-acquisition setup in my garage and it would have been used already for this and other issues - but thanks for sharing, I wish I had something similar to offer), the question at this point is what temperature to run your engine at. I've never really understood the cool, normal and tropical thermostat options from Nissan. The tropical and cold options seem like band-aids for a limited cooling system design. In principle, the radiator, fan, water pump, coolant channels, etc. work together to keep the engine temperature stable at a set point, regardless of the climate. The thermostat determines what that internal engine temperature will be. You should change thermostats because you want the engine temperature to change, not because the external climate is changing. So, the evidence from the cooling fan and the thermostat experiments both support the idea that residual heat from the engine is the problem. Now, what is the optimum temperature at which to run your engine? If it's 180, then you need a fan or some other method to avoid the heat soak problem. If it's 160, then put the 160 thermostat in and avoid the complexity of the fan. Kind of how I see things. I don't know what the best temperature is to run my engine. Seems like Nissan would have made the 160 thermostat the standard if 160 was optimum design temperature and it removed the need for the cooling fan, for the ZX's. But, maybe it's just a simple emissions or mileage issue and they had to stay with 180 as the standard. Maybe 160 is better for power and longevity? An "Optimum Engine Temperature" thread could get pretty long, I assume, but it would be interesting.

Not specific to the original topic, but the Victor Reinz gasket is not cardboard, it's a thicker multilayer gasket. Another option. Plastic-y outer layer with a thin metal core. Quality isn't great, some trimming around the ports is necessary but it's different from the Fel-pro cardboard. I think it's the same gasket MSA sells. Harder to install because of the thickness and weight, definitely a different design. I've used the MSA gasket for about 20,000 miles with no issues, then used Fel-Pro's paper and had to retighten several bolts/nuts after the back of the exhaust manifold started leaking. I have a RockAuto Victor Reinz gasket waiting.

As for why different people see different effects, location could be a factor, as described below. We're not all using the same fuel. http://www.google.com/url?sa=t&rct=j&q=gasoline%20blends&source=web&cd=9&cad=rja&ved=0CGoQFjAI&url=http%3A%2F%2Fwww.gao.gov%2Fassets%2F250%2F246752.pdf&ei=SuPiUdrCHqr-iwLbmYCYAg&usg=AFQjCNEtVR2slSlQyHx6vqE68Uou0MnJag&bvm=bv.48705608,d.cGE Note the date - 2005. Who knows how many blends are out there now with ethanol addition. Here's another, newer, more general article - http://www.weeklystandard.com/articles/bureaucratic-gas_634424.html

Lots of interesting factoids listed there. But on my essentially stock EFI system, with N42/N42/N47 (intake/head/block) engine, and all the factory heat shields, new Nissan 180 degree thermostat (opened at 185 on the stove), new radiator, temperature needle rock-steady at a hair over center; the fuel rail priming and purging (new cool fuel run through it while waiting for fuel tank bubbles to stop) does not have any effect. It just doesn't do anything. The fan bandaid (fandaid?) has immediate and consistent effect. If I turn the fan on when I leave the car, it doesn't matter when I get back, 5, 10, 15, 20 minutes, doesn't matter. Get in, no priming, start engine, drive away. Just like a modern car. The only way it could get better, for my situation, is if I could find a decent automatic timer for a reasonable price. The hundreds of Asia-made turbo timer options look interesting but seem way overpriced for what they are. That's my anecdote and I'm sticking to it. Priming doesn't work, fan on injectors does.

I recall a difference in gland nuts between KYB and Nissan. My 76 had the Nissan originals on the front and I spent some time comparing the two gland nuts trying to decide which was best, when I installed KYB's. The Nissan nut just looked better, but it wasn't right for the shock. The gland nut is a precision fit on the top of the shock, centering it and giving proper pressure on the shock when tightened (sometimes with a washer needed). The OEM nut was looser. You could probably build a collar to make it work, but it's not going to be right without some extra work.

Weren't you the one that proposed that it was fuel vaporizing on its way out overheated injectors that was the source of the problem? Can't remember who said that. I didn't have luck with priming the rail either. But I did build my own injector cooling setup using a ZX blower and some GM heat riser tube. Air blown directly on the injectors, with a timer to keep the blower on from shutoff for about 20 minutes (the critical time period for most people). It was just an experiment but it worked so well that it's still on there and I always use it. I forgot to turn it on twice, in the winter time, and the problem came back really bad. Here in Oregon, I'm convinced that they use winter blend gas from early fall to late spring, and that's when it's worse. Fuel quality as the other half of the problem could be why the automakers all went up in fuel pressure from mid-30s to mid 40s and higher. I tried to find a low flow injector so that I could run higher pressure but didn't get anywhere.

I've had the hot start issue and noticed that my gauge was always up at the three quarter mark after sitting. But my radiator was fine. It's just heat soak in to the thermostat housing once the coolant stops flowing. There is also heat flow in to the injectors and rail from the block and manifolds. Changing your radiator based on what happens when the engine isn't running wouldn't make sense. The radiator isn't really in use unless coolant is flowing.

You're describing three things that might not be related. Oil burning, cylinder pressure and throttle response. Quarts per mile is a common indicator of wear. How much are you burning? In general, these engines seem to run well while burning lots of oil though, so your lack of throttle response is probably due to something besides worn rings. Oil-burning would come from bad bottom (oil scraper) rings, poor compression and blowby would come from bad top rings. The wet test will affect the top rings, not the bottom. Cylinder pressure numbers vary a lot due to all of the different gauges out there. One person's 125 is another's 160.

A few of us - http://forums.hybridz.org/topic/113836-warnings/?do=findComment&comment=1066123 SuperDan initially commented that Google was screwing things up but removed his comment. Maybe he found something. Seems to come and go, I got two notices, but no more since.

I wrote a whole funny thing about your excellent use of grammar to convey your lack of knowledge about your car and its engine but chose not to post it. Seriously, you write unusually well. Therefore: Find and open the FSM for your car from the link below and read the Engine Fuel chapter to understand the engine, and the Emissions chapter to understand the thing under the throttle body. Good luck. http://www.nicoclub.com/FSM/

Batteries take time to recharge. It's not instantaneous. Measure voltage while revving without the headlights on. Should be mid-13 to mid-14 volts. Or just watch the dash voltmeter before you start the engine and after. If it goes higher than it was at start, when revving, your alternator is working. If it just sits there, or slowly drops, you have a problem.

EF-7 has a diagram. You might find that relay and check it for power.

You only have 5 posts and none of them describe the engine or car that you're working with. "280 with a fuel pump hooked up to a switch" isn't enough information.

Combine the best, part out the rest. Many parts will swap between the two.

There are two circuits to the ignition system from from the key. One bypasses the ballast resistor to balance the current draw from the starter, the other uses the resistor once the engine starts. You might only have one circuit. Look at EE-26 here and check the wires around your ballast resistor - http://www.nicoclub.com/FSM/240z/1973/

You could just try both, with a timing light. Don't forget the HEI module also, as a cheap alternative. Just use the wires from the magnetic pickup and take the E12 off completely.

Here's a picture of a typical factory stock 280Z head pipe. I have several and they all look like this.

If you've removed any heat shields around the engine you should put them back. Also, winter blend gasoline seems to make the problem worse, for me anyway. So if you're still on a tank of winter gas, go get a fill of new gasoline. My engine had terrible hot start issues in the winter.

There's a problem with the L6 and EFI commonly called the "hot start" problem. Nissan installed a cooling fan for the fuel rail and injectors on the S130's to try and avoid it. Search "hot start" or "vapor lock" to get some ideas. Did the engine not start at all or did it start but run so bad that you shut it off and waited?

So the car is still sitting where it wouldn't start or you had it towed somewhere? It has not started since then? It's probably cooled down so a plugged radiator wouldn't be a factor.

Drawings of the brake system are in the FSM - http://www.nicoclub.com/FSM/ Could be rust in the actuating mechanism or rust in the drums. You can see the parking brake lever and end of the brake cable if you stick your head under the car. Have someone move the brake lever and see what moves. If you have to take a wheel off and beat on things, be careful with the brake drum. They break. There's also an adjusting wheel inside that you can turn to loosen up the shoes. Might help if the drums are rusty. It shouldn't hurt anything if you use the engine to try and break the shoes free if you don't get crazy with the clutch.

Shows up here and here. Part #18. Who knows about real availability. On the Z and ZX R200's it installs in the internal groove in the diff. before you insert the axles. Later axles (the VLSD's for example) had it installed on the axle itself (may be why there is none in yours). Check groove sizes, chamfers, etc. to make sure you don't get an axle stuck. Someone who knows Quaife's could advise better for your situation. http://www.carpartsmanual.com/datsunS30/DatsunZIndex/PowerTrain/DifferentialGear/R200/tabid/1727/Default.aspx http://www.courtesyparts.com/clip-side-p-351272.html

Here's another, even more recent. 73 seems to be the year of change. Early hubs have a "scalloped" shape to them, apparently. Later are just round. http://www.classiczcars.com/forums/getting-help-your-z/49855-new-centric-rotors-dont-fit-%5Bshorter-hat%5D.html