Zed Head

A shorted condenser seems to fit the symptoms. The OP could check continuity from the condenser body to the wire end. Or just disconnect the condenser at the other end of the wire (it should have a bullet connector) and see if it still drops voltage when connected.

Curious - what, exactly, would the "clog" be composed of? Will anything really get all of it out?

Looks like oil-covered rust to me. Did the car sit for a long time before you got it? Might be worth the time to remove the rocker arms and clean them up with Scotchbrite along with the cam and lash pads to see how pitted they are. Keep them all in order, they need to go back together just like they came off. It might be fine and I'm sure the rust, as a high spot, is screwing up your lash adjustment. The most expensive part of a cam swap is the rocker arms, I believe. Might do the math before you decide on that route.

Re disepyon's suggestion about plug order - the engine will run with the plugs installed in the right order but wrong rotation direction. Maybe your mechanic assumed clockwise instead of counterclockwise. I've done it. Very confusing, especially since the engine will start and run.

Just stopping by... Thanks for all the pictures. I haven't disassembled a good running engine so haven't really examined those parts up close. The wipe pattern on the rocker arms (where the cam rubs) looks centered and smooth, which is good. The lash pads with the close-up looks kind of worn, is that spot depressed or just looks worse than it is? As I understand it, you can put new or resurfaced, rocker arms on an old cam, because the wear surface is perfectly smooth with no high spots to cause rapid wear. So a new arm and lash pad should work. Looking at your pictures, I see the spray bars and wonder if it's possible that one got bent and is touching a valve retainer or rocker arm during operation. They're easy to bend. Worth double-checking. Good luck with it, someone with more experience will probably be able to tell you more about the pictures.

Actually sounds even odder. He's (You're) saying that the "loose" one is too tight at the cam lobe. Therefore all of the others should be even looser. Something's off. If you want to be sure the retainer spring isn't too tight, press down on the rocker end like you did in your last video, while you slide the feeler gauge in. That will take the retainer spring out of the situation. It will be crowded with a screwdriver in the way, but worth a try. Edit - Added a You're...

You should use the numbers you've shown between the cam lobe and the rocker arm. My point was that maybe you're not getting a true measurement between the actual rubbing surfaces of the cam lobe and rocker arm. The gauge might be rubbing on a high point, or the retainer spring might make it feel like a tight fit when it's not. If one is loose they should all be loose, unless your lash measurement was incorrect. The procedure is in the Nissan FSM. The .012 and .010 measurements are between cam lobe and rocker arm when warm. Recheck after you tighten the locking nut since the tightening will decrease the lash a small amount. For what it's worth, from a materials science standpoint, assuming that the components all expand at the same rate (they will since they are made of the same metal) and the running temperatures of the components are essentially the same (why would they not be), there's no reason not to do it cold, using the .008 and .010 numbers from the 1976 FSM. It's easier, less painful, and you can take more time to get it right.

Feeler gauges too wide and you're measuring the wrong clearance? Measuring lash on a rocker arm or cam ridge? Maybe the rocker arm retainer spring is tight enough to give you a false reading on your lash. Looks like you're pressing pretty hard to get the rocker arm down. You're pressing against the retainer spring pressure from the other side, I assume. Is it out of its groove or bent?

Just a possibility - could you describe the relay that you replaced or post a picture? Are you sure that your car is a 77, and not a 78? 78 has a separate fuel pump relay and a separate "fuel pump control" relay. Early 78 cars were made in late 77, so if you're basing the year off of the door pillar tag, you might be a year off. If it's a 78, there might still be a relay to look at.

That's a more likely possibility. Over on hybridz, disepyon posted pictures of the exhaust leak and surprise that the leak was on the side with the intact stud, and the broken stud side was sealed. That would be a pretty good sign of a warped sealing surface. If the manifold sealing surface wasn't ground flat, there might still be an leak despite the new studs and gasket. Exhaust leaks can be hard to fix.

Might be time to put the time in on the wiring diagram. Here's one from "Mike" the Admin - http://www.classiczcars.com/forums/downloads.php?do=file&id=2 I'm not sure who put it together (maybe Saridout) but the color coding makes it easy to use. You can see that the green wire to the pump is green all the way to the connector by the passenger seat at least. It shows as green to the pump relay, but so do all of the other wires so that part might be incomplete. But you can test continuity from the pump to the connector, then from the connector to the relay (check wire color from the connector forward). If you have that then you need to test for power from that pin on the relay. Another thing to do would be to check for power at the AAR connector. It gets its power from the same source, at the same time, as the fuel pump, in parallel. No power at the AAR means that power is not coming through the EFI/Pump relay. Same test, disconnect the starter solenoid and turn the key to Start, check for voltage at the two pins in the connector at the AAR. One gets power the the other goes to the ECU.

You've shown that you have spark, or ignition, to #1. An ignition problem wouldn't be the source of the noise. It would also be pretty interesting if you could have something bouncing around in the cylinder for as many cycles as you've described without the piece exiting through or destroying a valve. It seems unlikely that something is in there and it only makes noise when combustion occurs. Copied this from your first post - "The sound actually gets louder when the car is warmed up." Valve lash grows when the engine gets warm. Kind of sounds like you left one of the rockers with a loose adjustment. Not sure why removing spark would remove the noise though.

Thanks for the feedback. I realized that I now have three spare rods in the garage, plus the two on the car, so went out and used the edge of a small adjustable carpenter's square on them. Two are perfectly straight and one is bent. One on the car is very slightly bent, the other perfect. Seems like the bend's only real effect is to pull the end of the transverse link (control arm) back slightly due to a decrease in effective length. Changing the wheel base on side. Something that happens anyway due to the elastic bushings on the end of the TC rod and the elastic in the inner bushing. The factory front suspensions on these cars seem to be pretty flexible. The only time the wheels are properly aligned would be when cruising straight down a level smooth road.

I'm talking about curvature that is designed in to the rod by the Nissan engineers. The rods seem pretty stout and it doesn't seem that they would bend in use. Placing a jack under it or bumping a rock or log might do it, but the loads in use are lengthwise.

Just curious, and I've mentioned this before in another thread, but does anyone know if the TC rod was designed to be straight? I think that it's a cast piece with forged ends, or the whole thing might be forged. Designing some bend in to the rod for safety during an accident or shock absorbing ability would be reasonable. There's really no reason for it to be perfectly straight.

www.xenons130.com/reference has an FSM to download that will have the instructions and specs for re-assembly. Engine Mechanical chapter. Hopefully you already have it and used it for dis-assembly and will give some good instructions to the shop that rebuilds the head. There are some simple, easy to make mistakes that can cost you a lot of money if the shop makes them. Hit the caps button for "I" and the start of a new sentence, if you can. It makes the world a better place and builds character.

POR-15 will often clog the inlet screen when it's used to seal the inside of a gas tank. If you get poor flow from the mechanical pump, you might confirm good flow from the tank outlet before doing any pump work. www.xenons30.com/reference By the way, it's a simple courtesy to put some effort in to your posts and capitalize. Shouldn't be too much to ask for all of the assistance you're getting.

You can buy pre-fitted and flared lines of the desired length, with the proper thread, from most auto parts stores. With a piece of wood and some wood screws you can build a jig for making the bends. Or if you're in a hurry, you could just screw one end in and make it work, and re-do it later. Take a length of string or wire to the piece you have to get the length dimension you need. You could have it done in a few hours.

High RPM ignition breakup could be the ZX ignition module. Module problems quite often go away when the module cools down. If you take it out again and the problem is gone but comes back after things get hot, that would be one thing to think about. It's been suggested to take some sort of cooling spray in a can and spray the module when it happens to get a better diagnosis. Not a cheap fix though. Verify timing and fuel before getting carried away. By the way, the 260Z already had electronic ignition. Did you install the ZX distributor or did a PO?

We've been focusing on power but haven't talked about grounds. Have you checked the ground circuit at the pump? I would check for ground at the pump black wire with an ohmmeter, then test for power at the green wire with a voltmeter or test light while someone turns the key to Start or fingers the AFM vane with the key at On like rcb suggested (77 still has the AFM fuel pump switch,according to the FSM). Then you'll know for sure that you don't have the circuit you need.

You could also remove the two bolts that hold the inner part of the transverse link to the body and remove the strut and spring with the transverse link as a unit. May or may not require removing the brake lines, depending on how careful you think that you can be. You might have to remove the brake lines anyway to get enough distance to drop the strut down. Considering that you didn't know about the spindle pins before, the odds of you getting the pins out without damaging them are not in your favor. They rarely come out easily, usually they're destroyed in the process. If you really need the car before the weekend, don't even start on the spindle pins.

The Start circuit bypasses the alternator and oil pressure safety circuit and sends power to the pump. As I understand things. So disconnecting the starter wire and turning to Start should be testing the pump and wiring, without the alternator or oil pressure interfering. When you pulled the hose and looked for fuel, are you sure the pump wasn't running? Maybe the pump was running but no fuel was pumping for a different reason. The green wire with a white connector on each end, from the positive terminal is the EFI fusible link. I don't know if that would kill power to your pump or not. The wiring diagram shows power to the pump through one of the four under the covers, if I read it right.

Alrighty. Just trying to understand. The fuel pump relay is one half of the 1x1x2" silver relay by the hood latch release lever. The other half is the EFI relay. Power is supplied through one of the four fusible links under the hood. Maybe you blew a link. Edit- that's three for checking the link. You might check the bundle of connectors right next to the passenger seat, between the door and the seat, under the carpet, also. One of those connections is for power to the pump.

Are you confirming what I said, or adding detail to the question? Not clear. There's no priming on the 77. Have you tried the common method for testing the pump - disconnect the small wire from your starter and turn the key to Start? The pump should run without the starter cranking. I think that the main relay by the hood latch release lever is the combined EFI and fuel pump relays. Edit - changed "ignition" to EFI

You do know that the pump only gets power when the engine is running or when the key is at Start? It does not have power when the key is at On.