NewZed

Still no picture. I'm going to guess speedometer cable.

johnc also had a good point about mechanically adjusting the rears. They're supposed to self-adjust with parking brake usage but the mechanism tends to get gummed up and stop working. On my car I can tell when I get another notch, because the brake pedal gets a little higher. If the rears are out of adjustment you'll have wasted pedal travel.

The booster has a big effect on effort. When they go bad, the engine idle speed will change when the brake pedal is pressed. The stock brakes actually work well when everything is adjusted right. In other words, it's not normal for a Z to have crap brakes. The brake light isn't tied to fluid level on the Z's (ZX's maybe), it's used to indicate an imbalance between front and rear systems. The light went out because you fixed enough of the imbalance when you bled the fronts to keep the switch centered. Check that the PO didn't put the calipers on the wrong sides also. Bleed valve should be up.

Check your tension/compression (TC) rods. When they break, the wheel can move forward easily, and backward too if the rod comes out of the socket. I broke one and the tire left a nice wear mark on the front inside of the fender well.

Did you remember to remove the chain wedge?

I've seen several small block chevy engines do this after wiping a cam lobe. Might check the mechanicals since the electrical and fuel look right. I've seen it described also, on this forum that the press-fit distributor shaft can spin. Timing verification is a good idea. Checking for a tooth jump on the cam chain is easy enough, using the notch and groove, and the zero timing mark.

Could be the BCDD 10 mph switch.

Sounds like your rotating the crankshaft, sprocket and chain as one, after pulling the sprocket off of the camshaft Take the chain off of the sprocket, rotate the sprocket to the desired hole position independently of anything else moving, put the chain back on the sprocket, carefully turn the camshaft the 4 degrees or so necessary to get the sprocket to line up on the dowel and put it back on. Start the whole operation with the timing mark at zero (#1 piston at TDC) and don't rotate the crankshaft at all. Don't forget to make sure that you're turning the engine the proper way also, when you check for chain stretch. If you turn it backward your marks won't line up right.

It's in there but it just says "Bleed air as follows; Rear wheels --> Front wheels" .

I've wondered about the insulators (retainers) also. I have the open type on my engine now, the kind with the stand-offs that leave the injector body exposed (might be why the fan works for me). It sounds like you might have the enclosed type that look like they would retain heat. One exposes the injector body to radiant heat, the other shields the body from convective cooling. Which is worse? On the manifolds - I wonder if people with headers have less problem since the mass of the header pipes is less than the mass of the factory cast manifold. I am pretty sure it was cgsheen that suggested side-feed injectors would help avoid the problem since they run fuel around or through the body instead of passing it over a supply hose. With our injectors the fuel passes ~2 inches away from the injector body, only convection mixes cool fuel with hot during a prime.

Sounds interesting but you've basically moved on to basic engine parts cooling. My main interest was in the pros and cons of the 72 degree thermostat versus the 82 degree. Basically, is there a trade-off in running one thermostat versus another. I have a fix for injector heat soak, I'm just trying to learn more other stuff, in general. Sorry I can't help but it bothers me just to see pictures of Z's with the hood cracked, let alone drive around that way (no offense to those who do). Plus putting up with all of the people trying to signal me that my hood is open as I drive around.

Might not matter, but that would be 8 mm and 10 mm, most likely.

If you read through the MSD site you'll see that the 6AL is essentially the same as the 6A except for the addition of some rev limiters and internal upgrades. That's why the 6A is NLA. But the external wiring is exactly the same (Page 4 of the instructions for both the 6201 and 6425 is identical). The instructions for the 8910 and the 8921 show that the ignition control used doesn't really matter, it's the tach type that determines which to use. And, for anyone that wanted to dig deeper, it really looks like the 8910 is just a condenser/capacitor in a fancy package, and the 8921 is just a small amplifier. Probably why some people get their early tachs to work by adding a few more loops to the circuit in the tach. You get a stronger magnetic field with more current or more windings. http://www.msdignition.com/instructiondownload.aspx

Start at the link below. You can print the EFEC pages for your Datsun specialist or get a multimeter and do the testing yourself. Good luck. http://www.nicoclub.com/FSM/

Do the TPS test at the ECU. Take the plug off, identify the TPS pins and do the test. See what the ECU sees. Then you'll know for sure. New parts may not be communicating properly. Actually, at this point, sitting by the ECU plug with the FSM and a multimeter could find you a solution. At least you can be more confident it's not electrical and spend your time looking at the mechanical things like the various vacuum valves. One off-the-beaten-path possibility is a corroded EGR passage or stuck EGR valve. Full time EGR might cause your symptoms. Doing the ECU tests at the ECU first makes sense though. It's tedious but you'll probably find some things that aren't quite right.

Did the new distributor fix the original, cold start (warm up) problem, or do you have a new problem in addition? Two problems now, or one new one? Have you tested the TVS (throttle valve switch, aka TPS, page EFEC-56) ? The ECU uses it to know if the throttle is at idle, mid, or full throttle. Your two problems seem to fit a TPS issue.

For anyone interested, here's the Grape Ape Technical Articles site. The Cooling link has good descriptions of the basics. http://mysite.verizon.net/vzezeqah/id1.html Odd that it doesn't have Grape Ape in the link, but I think someone moved the files over. It seems to be the real deal. Nigel, on the use of a fan, mine is a ZX fuel system cooling fan (described in 1981 FSM EF-46) with a GM heat riser tube attached to the fan's outlet and laid down under the fuel rail on the L6. The end of the tube is plugged and 6 holes, ~1/2 diameter are used to direct air directly on to each injector. The rest of the engine just stews in its own heat, no fan, no hood vents. Only the injectors get air, drawn from the right above the oil filter. The fan is run off of a bathroom fan timer, mounted by the steering column, the factory thermal switch is not used. Your problem is really interesting since your engine is quite a bit different from a typical NA L6. Here's a link to the type of heat riser tube, it's the typical accordion-fold metal/fabric material hose that GM used to bring warm air up to the intake manifold. I got mine from wrecking yard S10's. http://www.amazon.com/Standard-Motor-Products-Pre-Heater-Hose/dp/B000C7UPQU/ref=wl_it_dp_o_pd_S_nC?ie=UTF8&colid=30R38L6H5WA0Q&coliid=I2PEPLP3OQMVN8 Coincidentally, I forgot to turn the fan on twice today (subconscious maybe...) and got typical heat soak/hot start problems. As it clears up it seems like one injector takes longer to clear up than others. Runs on 5 cylinders for a while. The second time the temperature gauge was still reading normal. Who knows, a 160 thermostat might help. I'm running Bosch 028150116 injectors, not the stock Nissan green ones. Just filling out the picture.

I've taken a few items for general response. The last two out of order. These first two things are just odd, and disingenuous, and might be self-reflective. None of it applies to me, I've never been accused of anything similar by anyone, ever, and I've never felt an inkling that I should examine what I was doing because some of these things might apply. It is sad. If there was anyone out there that I thought could dig in to this issue and come up with some rational reasons for why it happens and how to stop it, it would be you (and several others who have may have seen this thread but knew better than to get involved). Maybe though, this is your "white whale" and you're having trouble dealing with the fact that it can't be caught. You don't understand it so you just keep throwing the same old harpoon. Or you could just be a bully, in general, and can't stand to lose a bullying session. That actually fits with some of the other threads you've been a part of. Now you've given up and taken the path of full-on verbal personal abuse and bluster, in public. That is truly sad. As you're trolling the internet in the future looking for some newbie to abuse, or a thread to interject your FACTS! in to, put a little more thought in to where it could lead. Think about leaving sooner. This is a pretty ugly end to what was an informative thread. You can do better Tony D. Still lots of time left.

Measure fuel pressure. Leave the gauge on while you drive. Knowing that you have proper fuel pressure at the rail takes fuel supply off the list of potential problem sources. Filter, pump, relays, crud in the gas tank...you can stop worrying about all of those if your pressure is correct but the problem is still there.

I wrote up a whole thing here but realized I was just churning up dust. We're still left with two potential fixes for the hot start problem. A cooler than recommended thermostat (deviation from the FSM instructions based on Tony D's advice) or a cooling fan (modified from the factory ZX fan scheme, to blow air directly on to the injectors). Both deviations from factory, and apparently both work. A choice. The reasons that Nissan used three different thermostats are still unclear, as many things are since we don't have the notes or minutes from the decision-making meetings. But Tony D has listed many of the effects of using coolant temperature control. Removal of the heat soak being one potential benefit. I still disagree that using the fan to solve the problem, while keeping the hotter thermostat is incorrect, in any way. It's just another way to get a job done, completely within the parameters of correct and careful engine operation and maintenance. Using the 160 thermostat is just the Tony D way, and incorrect, by the instructions of the Nissan engineers. It's just the way it is. There's nothing wrong with deviating from instructions, but you do lose the right to say other people are doing it "wrong". Better to say "here's how I do it and here's why I think it's a better way". Somewhere in the last page or two I think there is some of that along with a lot of extra stuff. Even better, in addition, explain what the Nissan engineers were thinking, if you know, for context. I'll still be searching around for information on the effects of combustion chamber temperature on performance and how that can be affected by coolant temperature, in addition to effects on lubrication and clearances. Ideally, one could summarize things down to pros and cons of hot versus cold, for use in decision-making. Maybe it's all hidden in this thread somewhere.

You've missed a lot of discussion about why flipping the cages doesn't always work, in your searches. If CV axles are crucial, this thread is probably where you want to go - http://forums.hybridz.org/topic/112204-order-for-shorter-z31-turbo-axles-from-the-driveshaft-shop/page-2 Search "chequered flag joe" for the other parts. Here's one - http://forums.hybridz.org/topic/103581-billet-z31-cvcompanion-flange-adaptors/ Use "site:hybridz.org" with your search terms, on Google instead of the Hybridz search engine. You'll find more stuff.

Seems like all you really need is two new yokes. All of your damage pictures are yoke only. The yokes fit the u-joints so two new (stronger) yokes should get you back in business. I assume the twisty portion wasn't there in the beginning. Looks like the CV axles with no heat treatment. JTR may have got a batch of yokes with poor heat treatment.

How hot everything is when you shut the engine off determines how hot the things around it will get once the coolant flow stops. So the thermostat used will affect the heat soak/hot start issue, since it allows more heat energy to reside in the engine while the engine is running. If the engine is hotter when it's shut off, the things attached to it will be hotter after it sits for a bit.

The very simplest way is to pop the stub axles out of the R200 that's in your 78 now and pop them to the 87-89 CLSD that you want to install. The CLSD will then bolt in just like the open diff that you're replacing, and you can use your u-joint half-shafts. Your scenarios 1-3 are all about getting CV half-shafts to work, which you probably don't need unless you're making lots of extra torque and have big tires, and want to use both to the extreme. bZ writes faster than me...and I forgot the part about the pinion flange...

Crack or cut a fuel line and see how fresh the gas is. That will give you an idea on potential for the EFI parts, like injectors, FPR and fuel rail. The 78 engine in my 76 now sat for ten years (I bought the whole car and the tags were ten years old) before it was re-energized. It's in great shape, no oil-burning, no blow-by, no problems.