Zed Head

The numbers look like those of the common 2.8 liter engine used in the 280Z. My 1976 L28 block, with N42 head, has number 071155 stamped on it so your block is newer than 1976. In the states, they started using the N47 head in late 1977, but maybe the N42 was used outside the states. Where do you think the engine came from, Japan, US or Europe?

The GM 4 pin module has to be electrically grounded through one of the mounting holes to function. I have read that they can be damaged if they lose ground, so yours may be damaged if you tried it without. Some people (me for one) run a dedicated ground wire from the mounting hole to make sure they have a good connection. The heat sink and the ground serve two different functions.

I've not heard of "light-duty" KYB shocks. How are they described? I do know that the GR-2s are now called Excel-Gs. It's on the KYB web site. They say that they are the same except for color and name. http://www.kyb.com/technical/faq/faq06.php

Dig in to the FSM a little deeper. There is a section on testing at the ECU plug and a section on testing the dropping resistor and injection circuit at the plug.

Regarding injector wiring and injector testing - don't forget that the Zs are batch fired. All of the injectors fire at the same time so you can move your injector plugs to any injector you'd like (if the harness will stretch that far). So if you know that 3 is firing, you could move it over to 4 or 5 to see what happens, or vice versa. If your plugs are fouled it might not tell much about the 4, 5 and 6 cylinders, but if you put 5 on 3 and it runs the same (when removing 3 causes stumbling), you could be confident that the #5 wire was putting out an injection pulse. Just another angle (if you don't have the Christmas tree lights, although I do like the idea).

You should check your fuel pressure before you do too much more work. Hook up the gauge, start the car and pull the vacuum hose off of the fuel pressure regulator. Pressure should sit at 36 psi. Reconnect the vacuum hose and pressure should drop to ~26 - 30 psi depending on intake vacuum. Without knowing that you have good fuel pressure, you risk spending a lot of time and money on the wrong things. Testing will tell you if the pump and FPR are working correctly, whether your lines or tank inlet are clogged, whether or not pressure is changing over time, etc. A few less things to guess at...

I had a similar problem where the air flow would not hold the AFM flap open far enough to get it off of the cutoff switch, so the engine would not idle at low RPM. It ran fine, just wouldn't idle. If the fuel pump keeps running when you hold the AFM flap open as you described, you should be able to keep the engine running by holding the throttle slightly open after it starts (which should open the AFM flap), or turning up the idle speed with the idle screw (same effect). If this works, then you might have a vacuum leak, which is letting too much air past the AFM flap. Find that or the adjust the fuel pump cutoff switch mechanism. My problem started when I advanced my timing. The engine needed less air to maintain idle speed so the AFM fuel cutoff switch started killing the pump at idle. I ended up bending the switch mechanism so that it would stay closed at lower air flow. You can see the cutoff switch and how it works underneath the black cover on the side of the AFM.

Your results show that the parts you tested work correctly. The fuel pump runs when cranking. When the engine starts, you let the key go, but the AFM flap is open now from air flow and the fuel pump keeps running. If the engine dies, air flow stops, the AFM flap closes and the fuel pump stops running. So no problems with your fuel supply to the fuel rail, at least from the fuel pump outlet. Is there another problem?

If you post pictures of the mechanism cover that you have and the seats you're trying to fit, you'll probably get many more responses from those of us who can walk out and look at what we have.

5th gear tells the story. Look at Post #2. Use white out to make a couple of marks and turn the input shaft one turn.

palladin over on zcar.com figured out a rebuild procedure and wrote it up. It seems pretty popular, especially for those on low budgets. http://www.zcar.com/70-83_tech_discussion_forum/heater_valve_repair_895221.0.html

You might be able to take a thin fairly stiff sheet of something like Mylar (transparency sheet), make a tube of it, wrap it around the speedometer body and get the speedometer to slip back out. Lubricate with soapy water or Armorall. Or take some packing tape (again smooth material, with lubrication) and tape up the lip that it catches on when trying to push it back out. You could even build a small ramp of tape up to the lip on the dash cap. Anything to turn the lip in to a smooth transition. The cap is probably flexible enough to expand out if you can get the body of the speedo over the lip. Or wrap tape around the front of the speedo face to take the edge off and give something to wedge it in and pull it through the hole. Again, with some sort of lubrication. Get the idea? Just some options.

Doesn't the brake line enter in the middle of the piston cylinder? Is it possible to swap bleed valve for brake line?

Bleeder screws at top of all four calipers? Easily overlooked, it just happened to a guy over on Hybridz and he wrote a whole page about it. I have also read that the Toyota calipers sometimes need a little extra work to get the bleed screws oriented correctly, but I can't remember if it was Toyota on the front or back. Worth double-checking. If they're not at the very top of the internal cavity, there will be an air pocket.

For your future reference - JMortensen (aka "Someone") posts on classiczcars quite often also - http://forums.hybridz.org/index.php/topic/99447-trans-diff-identification/page__pid__932664#entry932664 The internet seems huge but it's really pretty small.

Thanks Zedrally but I kind of over-reacted. Zcars.com doesn't allow soft porn so this kind of video is not all over their site, but there is a bunch of other nonsense that goes on. I had hoped that the guys from zcars wouldn't bring it over here when they defected. bgm, can't you just keep this stuff over at zcars? It doesn't really fit this site.

Mods, please don't let classiczcars.com go down the same path as zcar.com. This crap (the French Maid video) is all over zcar.com and is a big part of why it sucks.

I have some KYB GR-2s coming tomorrow so took the front struts off tonight and found that I still have the original piston/cylinder setup from the factory. The oil in the struts smells like the old California oil wells that were still active in the 60s. Are these worth anything to anybody? It's a 1976 so not quite a classic but someone might appreciate original. If so I'll hang on to them.

If your car has a newer 4 speed it might also have a different differential. You might check your rear gear ratio before you go, just so you know what you're working with. Plus, if you are still stock, that 3.36 ratio will be in an R180. The ZXz will probably be R200s if they are manual, which will be more work to swap in. And the 78 Z 5 speed most likely has the same first four gear ratios as your Type B 4 speed. Using it would give you the same ratios you have now, plus one more. There's a variety of combinations to choose from.

I'm more curious about his uncle did the turbo modification, way back then, without the internet and the various Z car forums that we have available today. I haven't seen a D&M marine intake referred to before. The connection with Air Research sounds interesting too. Sounds like a unique setup.

What do you now about the turbo-charging modifications? I've read several accounts of bolting a turbo on to an engine that was originally NA, but they usually end up a with a non-optimum setup (compared to the later turbo motors) unless they go to aftermarket engine management (which would not have been available back when your uncle worked on the car).

It was a garage-floor setup. Feeding right back to the negative post. The voltage is high but the amps are low. Plus, in the car, that is actually what happens anyway. Even though the electrons have to travel through a mass of engine block and some wires to get there. No problems, no worries, except that you should make sure the area around the battery top is open and ventilated. Out in the open on the garage should be fine, the spark will be no bigger than when connecting a battery cable with something on. Batteries produce a small amount of hydrogen gas as a byproduct of use (never use a lighter for light to check your electrolyte level).

Thanks LeonV, that's about where my thinking was ending up as far as how the tandem system worked. Except that for my 1976, the primary would be the first piston (the one contacted by the rod from the brake pedal), which would be the front brakes (the first, big, reservoir) and vice versa. So, essentially, if one system has air in it, the piston will run out of travel in its half of the bore before it can build up pressure to actuate the brakes, if the other system fails. That makes sense, and would explain the partial brake power - some pressure buildup but not enough. One good reason to shoot for a perfectly bled brake system, that I had not considered before. It's easy to live with a little extra travel in the brake pedal, but I didn't realize it would defeat the safety factor.

Sorry about the confusion, I was thinking of the wrong valve, the NP valve versus the warning light switch. And I'm still not clear on how exactly the NP valve works. Can't tell for sure how the tandem MC isolates front from back either, I will have to dig in to it. It sounds like you can have good brakes, but still not good enough for if one end fails. In 5th's case, the front brakes do most of the work anyway, so he should have had plenty of stopping power if the front and back are truly isolated. So it's not clear to me why he had essentially no stopping power when a rear wheel cylinder went out. Do the brakes have to be perfectly bled to be safe, rather than just feel like they work fine? Edit - just to add another thought. Both the brake warning switch and the NP valve have seals in them to isolate the fluids but to allow the transfer of some pressure, front to back and vice versa. Enough to move the switch for the brake check and to transfer some pressure for the NP valve. If the seals went bad, is it possible for the fluids to leak through? If so, you could have functioning brakes that are not isolated front to back. Bringing it up mainly for discussion, but also for safety.

After I read your story I thought the same thing that LeonV did and almost responded the same way. But, coincidentally, I had just bled my rear brakes so it was fresh in my mind that the pedal (in my car) will go all the way down if the back bleeder valve is open (similar to a blown wheel cylinder). I also checked the FSM and came to the same conclusion about how the master cylinder works. I wonder if the pressure differential valve is working correctly, on your car and mine? As mentioned, I too thought that it would isolate front from back if the pressure differential was too great, but my experience with bleeding the backs on my car, and your wild ride don't support that. Maybe our valves are not working right. I've searched the FSM but have not found where it says explicitly that it does more than make the Brake Check light go on. I'm curious, if anyone knows for sure. It would be worth tearing things down to fix that valve if it is supposed to be a fail-safe device. Edit - LeonV, I believe your story, just looking for more examples and insight. You might have had a slow leak that still allowed some pressure buildup(maybe?).