Zed Head

I would put the idle problems firstly. A big vacuum leak might have that effect. When you say it won't idle correctly do you mean when cold or at any temperature? What happens if you just open up the idle speed screw on the throttle body to increase idle speed? Does the AAR work correctly? Anyway, there are pictures out there of rotor position but I can't find them. The other way is to check the drive spindle tang.

That's the rest of the story. Apparently, he smelled smoke, then, later, he measured cylinder pressure and one was low. But he didn't spend much time talking about what the actual damage found was. " I just measured healthy compression a week ago, why would shortly after my drive a piston burn up? Issues within the distributor? Maybe this piston was on it's way out already?" It's a bummer but it might be that the cause is completely unrelated and he's jumped the gun. Too soon to assign blame.

Isn't it more likely that the engine started running poorly because of the broken cap, the driver got angry and started "beating" on the car to take out some frustration, and the over-revving holed a piston or broke some piston rings? That's the sub-text, I think. The broken cap caused the frustration which caused the engine abuse which caused the engine damage. So there is a path back to 123 but it's a stretch.

Seems like you had a confusing problem, blamed the wrong thing for the cause, tried to force 123 to accept blame for something that any reasonably knowledgeable mechanic would not accept as the cause, then they eventually tried to help you out by refunding your money with no restocking charge. At the worst, they sold another broken distributor cap. That's the only real fault here, that I see. You spent more time complaining about 123 than analyzing the problem. You even said that you can't be sure it was the fault of 123's product. Stuff happens, especially with these old cars. " Did it lose vacuum? I just measured healthy compression a week ago, why would shortly after my drive a piston burn up? Issues within the distributor? Maybe this piston was on it's way out already? Both possible and I agreed that there were too many variables to prove."

Your ignition timing, as shown by the flashing light and the timing mark on the damper pulley, and your drive gear and rotor are really two separate things. And the fact that it won't stay running at low RPM is probably not a timing issue. No offense, but you're getting things blended together. What you're doing probably won't fix your problem, unless the mark on your damper is incorrect and what you see by the timing light is wrong.

The head gasket usually tells a story. Check it carefully.

Spreading the bent part out slightly with a chisel or drift should be enough. Oil them up before removing so that they can re-expand more easily. Think of it as a machining operation. Sometimes, apparently, the threads next to the flats get damaged during nut removal. But, because there are flats next to them I don't think that they supply any real holding power. It looks bad but it doesn't matter as far as function.

Those last two are good ones. I had a 78 parts car that would catch, then let loose (catch-grind-whiiiiirrrr), many times before starting. The pin in the switch was loose. Years later after the car was long gone but I still had the switch, I figured out what was happening and restaked the pin with a drift. It had just loosened up over time. The pins that you see in the video that Dave WM supplied. You could wiggle the loose one with your fingers. You can just see the staked ends also in the first image, above.

This part of their ad copy suggests that you'll get more road noise. They must have tried it on one of their own cars. Disappointing. It's a solution to a problem that people just don't have. Pretty expensive too. "Note:This kit will increase feedback felt through the suspension, and may increase road noise and vibration a bit (almost all suspension upgrades do to a degree). Based on overall design and quality of the pieces, we do not think it will be all that significant for most Z-Car owners. "

A dead tach could be a problem also. If it is shorted out it might be hindering the "break" part of the make-it-break-it spark generation cycle, since it's connected to the coil negative terminal. Has it always been that way? Yes, the module is up in front of the fuse panel. The parts on the 280Z EFI cars are interconnected. Problems with one system can cause problems with another. You might have some troubleshooting ahead of you.

That's a brand new thing. Looks like somebody at MSA came up with it. You raise a good point about the rubber. It looks like the part you have will dramatically increase travel before bottoming out. Not sure it's meant for just a one or two inch lowering. Too bad they didn't add adjustability. You're kind of on your own. No offense but I'm not seeing a big benefit to that part. I've not seen many people at all complaining about bottoming out after using lowering springs. To be blunt, I'd return them if you can. I think that they're meant for the "slammed" cars, not Eibach lowering springs. I'm surprised that MSA advertises them the way they do. Kind of worrisome. People don't really have that problem.

Post a link to the parts page. Never seen those parts before. Also, not clear what car you're working with.

The fact that it starts easily by push starting kind of suggests weak spark. Could be poor current flow through the coil and ignition module. You need high current to generate a good spark when the module cuts it. The low voltage during starting won't help. There's a color wiring diagram in the Downloads area. You could trace the path and check the likely spots for resistance/crud. Clean up the path for power to the coil and on to the module where it's grounded. 78 has the plug-in module, maybe remove it and clean it with some contact cleaner like Deoxit. Might also be that your coil and ignition module are just getting old.

I think that the process is described Honsowetz's or Monroe's book, or both. I've thought that torque plate would be best for machining. It would take some ingenuity, maybe counterboring or even threading the bolt holes. But then you could flatten it via bolt torque to the top surface and skim just the odd high spots on the mating surface. When it's bolted on to the block it will be the same as on the torque plate.

I got curious about the need to shave or skim the head if it was out of spec. for flatness. My head was at the limit, bowed up in the middle, so I put it back on with no head gasket and tightened it back down to see how much it would take to make it flat again. It didn't take much to close the gap. I'm pretty sure that the How to Rebuild book uses a wider range also, I seem to recall .007", not the .004" that Nissan uses. The resurfacing has always bothered me because it leaves the valve train spec'ed to a different surface than the bottom of the head after skimming. The valve train is still warped. But if you tighten it back to flat using bolts then the valve train should straighten out also. Just a thought.

You can make your own tool from a piece of wood. Not much to them. Head gasket seems most likely. I haven't seen much about cracked heads, especially the later years. But, it's usually overheating that causes the HG to leak, which also causes the head to warp. But, also, I found that it really doesn't take much force to bend the head. You can "reflatten" it with a single head bolt and a short wrench.

He's using the same picture for both pumps, which he borrowed from Rockauto or some other site, or Airtex themselves. So you don't really know which pump you're getting. He might be selling the $30 pump for $67.50. I'd call and ask for the brand and where he gets them before buying. https://www.rockauto.com/en/moreinfo.php?pk=60014&cc=1209260&jsn=364 https://www.rockauto.com/en/moreinfo.php?pk=60014&cc=1209260&jsn=364

I think that they reduce the odds of leaks. Maybe also strengthen the seal for when you bump the bottom of the pan on something.

If stopped working means it just quivers and jumps or it doesn't read right, that sounds like the ignition module. They go bad often these days after 40+ years.

I was going to mention that you don't have to be exact on the rotations. For example, in first gear you'll have 3.592, 3.321, or 3.062, for example. 3.592 is between 3 1/2 and 3 3/4, 3.321 is between 3 1/4 and 3 1/2, 3.062 is almost right on 3.0, for one complete turn of the output shaft. Set your tail shaft indicator straight up, estimate the turns to get a full rotation and see what you get. The 1/4 turns are easy to eyeball. Once you look at the possibilities and try a few counts you'll say "it has to be ____".

Aren't you missing the reinforcing plates on the edges? Maybe they got rid of them with the F54 block. http://www.carpartsmanual.com/datsun/Z-1969-1978/engine-280z/cylinder-block

Forgot to say, you could put a little indicator on the tailshaft that's easy to see. Turn the input shaft 3.6 turns and you should see one rev on the back.

Looks like the 620 has the 240Z ratios, doesn't it? Better measure the length. It might be shorter. Leader...that's a good one. Just 'cause you're in the driver's seat doesn't mean you know where you're going. Especially with a whole car full of backseat drivers.

I've had good luck looking through the fill and drain plugs at the synchro and coupler sleeve teeth. I think it's third gear. They should be sharp and symmetrical. Rounded teeth is a sign of abuse.

It's your money and time. Cheaper than the wrecking yard. Good luck.