Zed Head

Yes, you can get both shift rods locking up a gear, two separate gears, before installing the case. That's actually very likely, looking back through the posts. But I think that the gear shift lever would be locked up, since it has to move the rods. But, if the shifter bushings are bad it might not feel like it. Mr. Ape threw me with his comment about the shady mechanic. Didn't realize it was him. What happens, what Patcon is suggesting, is that when you're installing the rear case both shift rods get moved at the same time, resulting in the trans engaging two gears at the same time. You could probably figure which ones by looking at the diagram. What people do to avoid that is to put the trans in to one gear before installing the rear case. Sounding like you installed the rear case with the trans in neutral and have that problem. It's a fairly common problem, apparently, I've done it myself even after reading about it, but noticed it before I torqued everything. And....you still have to remove the transmission to fix it. Edit realized that it's actually the front case that is put on last. AKA "bellhousing". That's when the shift rods get pushed backward. I first saw it described in the "71C" swap pages, then did the exact thing when I put mine together. It's on page 3 - http://zhome.com/ZCMnL/tech/240SX5spd/transmission.htm "When assembling the transmission, I found that having it in 3rd or 4th gear keeps all the shift rods locked so you won't bump the rods out of position and end up with 2 gears engaged and a locked up transmission. If you are in neutral, any of the rods can move. If in 1st or 2nd, the reverse-5th can move and if in 5th or reverse, the 1st-2nd can move."

I spent a lot of time trying to find little things like the chrome piece around the door handle ends, and the little cup at the door latch on the bottom of the door. There are many parts out there but most don't fit right anymore. If the guy has all of the parts saved in boxes you might be fine. People often take their cars apart though, because they look like they're falling apart already. A vicious cycle... Just realized that I never knew how to spell vicious. Thank you spell-check redline.

Are they 240's or 280's? Not the same. Match your parts cars if you're going to use them. You were looking at a 240 a 260 and 280 in your first post. Your parts cars can't match all three.,

A lot of missing parts. Those little parts are hard to find, even if some are in a bag that comes with the car you might end up missing some.

You could measure a valve's projection on that head you have assembled. Then you'll have all of the numbers.

You are the perfect customer . They put a few new parts in, but keep any old ones that pass a test. You can have old parts that pass but are hours away from dying.

Have I been working on your car...? Wait, I use zip-ties.... I guess not.

That's just a reman. Premier Gear and Hitachi are not the same company. Your Oreilly alt should have a lifetime warranty. Should be in the system under your name if you bought it.

You'd have to consider the angle of the valve to get its extension toward the piston but it seems close.

Alternator failure is common. You might be using the wrong FSM. You're looking for ignition ballast and external regulators on a 78. Both not there.

Probably here somewhere - http://www.carpartsmanual.com/datsuns30/Datsun-Z-Index/Body-260Z-280Z/2-Seater

The battery terminals are connected to what the alternator is putting out. It's the right place. Make sure to rev the engine while measuring. Slowly bring up the RPM until voltage stops rising. If it just keeps rising, over 15, you have a regulator problem.

1978 280Z's don't use the ballast. The 15 volts is concerning since the 1978 cars have an internally regulated alternator. Should only go up to about 14.3 or so at most. High voltage can mess up your other electronic parts. The tach jumping is a sign of a failing ignition module or a failing tach. Sending out extra sparks, that the tach can see but don't affect the engine. Probably want to check the alternator first, getting the voltage right might make the other stuff right. Like Patcon says use a voltmeter at the battery, don't trust the dash gauge.

I think that other types of problems might be getting blended together in the comments. With the clutch pedal pushed in the engine is disconnected from the input shaft. So the clutch seems to be right, it disconnects the engine from the trans, like it should. With the transmission in neutral the input shaft is disconnected from the output shaft. since the car moves with the lever in the neutral position, apparently, then there's a problem with the transmission. Here's another possibility - neutral isn't really neutral. I assume that you are assuming that the transmission is in neutral because the lever is in the middle and/or not in one of the gear slots. Maybe the transmission controls aren't doing what they should. Are the shifter bushings tight? Can you get the lever in to any position that frees things up? Maybe the detent pins/balls aren't detenting. Here's another - a broken or loose shifting fork. It might not be releasing the coupling sleeve. If this was the case you might find that certain gear positions actually lock everything up since you'd be in two gears at once. Overall though it looks like you'll have to get in to the transmission to see.

If he's getting actual movement of the weight of the car he has some serious binding inside. Sounds like the shady mechanic. You can turn the input and output shafts by hand, easily, in neutral, with the transmission out and on the ground. There's no way it should move the car at all, unless there's a serious bind-up.

Just a guess but maybe it's a sign that the ZX module is gong bad. Shorting to ground lightly, causing constant current through the tach circuit. If you have a spare module a swap might show something. Or the higher current flow from the ZX module and the coil is damaging the tach.

The LSD isn't doing much unless you're turning. No clutches slipping. Might be a clue. Check the simple stuff like lug nuts. They'll make those kinds of noises as the wheel wobbles back and forth. Pretty sure also, that somebody just had a simlar noise and it was the half-shaft flange nuts/bolts at the wheel. Check all of your nuts.

The head gasket/block/head combinations discussion can get convoluted. Especially if you get in to what the high power guys do to their heads to balance the cooling, drilling holes and attaching extra coolant lines. Sometimes people assume that all of the passages available need to be open and flowing as much as possible but if you follow the Nissan design path it looks like they modified the head gasket to control flow, by blocking or reducing the size of certain passages. There was a picture recently that showed it clearly with rust spots on the head gasket where the ports were blocked. So if you're mixing head and block you have some thinking to do. I've always thought that the head gasket should match the head. The head is what warps if cooling is bad, the block is essentially just a reservoir of coolant. And it's not a block gasket, it's a head gasket.

Exactly. I was just adding to the lack of clarity. For amusement.

Correct.

That color is hot.

The fragments would get splattered up to the valve cover and around up top but once they get to the pan they have to go back through the filter before reaching a bearing. Might be interesting to split the filter open.

People usually catch it sooner but, yes, that's the typical pattern. The pressure is on the lobe. A picture of the base circle might show a nice untouched surface. Here's an old thread -

It looks like just wear. Once you break through the surface the lobe can wear quickly. The base circle looks intact, it's on the rocker pad in the picture, which indicates proper valve lash. Fairly common, especially during break-in of a new camshaft. Some of the members here have burned through some cam lobes. @madkaw I think, for one, if I remember right.

The sporadic nature of your problem suggests those two electronic parts. There's not much to the HEI module wiring, on a 280Z. You can connect it temporarily in the engine bay with some jumper wires and a screw or two.