Zed Head

It does look pretty cool. I assume that the other end of the cable is attached to the heater control lever in the AC control panel. How does the throw at the panel match the throw at the valve? And have you tried it yet? Do you have a cooler cabin now?

Monroe's "How To Rebuild..." book says to put a bolt in the threaded hole in the cap, lay a 2x4 on the block, then put a pry bar under the bolt head and pry it up and out. It's a good book to get, if you don't already have it.

I run a flat bastard file very lightly over any flat surfaces once most of the gasket is removed. If it leaves marks on the metal around a remaining patch of gasket material I leave the gasket material as surfacing filler. Flat and smooth is the key for good sealing, not shiny. There are some good stories on other forums about heads and other parts being ruined or close to it through efforts to removed all traces of gasket material. Aluminum is soft metal.

Here's a good link - http://www.datsunstore.com/index.php/page/2/sort/2a/cName/engine-z-cooling-and-heating Might be easiest just to call and talk to Oliver.

Good luck with the manual boost controller and the RRFPR. I've still not seen anyone report that this method gave a civilized upgrade. Boost can be increased without blowing up the engine, but there always seems to be other problems that crop up. Interested in how it turns out. When you say "OE ECU", do you mean OE NA 1977, or OE turbo 83?

More on the oil behind the seal - I am fairly sure (not certain though) that there is a drain hole or slot at the bottom of the main bearing cap between the seal and the bearing. There's a gap between the seal and the bearing for sure, so no reason for oil pressure buildup. I also have faint memories of shining a flashlight in there while changing a seal and realizing that I could see in to the crankcase. I don't see any reason for oil pressure to have anything to do with the leaking seal. The oil should be fed in to the bearing, run out the sides and down in to the crankcase. Of course, I could be way off. Edit - there might be a way for pressure to build up if the drain hole (if it exists) was clogged. Maybe that's the issue.

Seems to me that that seal area is not supposed to get pressurized. Your oil pressure is good, the oil just doesn't have the proper return path to the crankcase. Looking at various pictures of the bearing cap and bearing, for whatever reason the gap between the bearing and the seal must be filling with oil faster than it can drain out. I would focus on that aspect of the situation, rather than oil pressure. But I've not had an engine apart so I'm just going off what would make sense if I designed an engine. Maybe Nissan did something different.

I think that he's looking for the multifunctional relay that has the alternator circuit and the oil pump switch circuit running through it to control the fuel pump power. The one that they used from 1978 on. Probably still work-aroundable, just not a simple circuit.

If the oil is clear, not milky, then light brown is normal. Water in the oil gets frothed up and creates an opaque milky emulsion. Looks like your problem might have nothing to do with cylinder, pistons, rings or valves. Your pressure numbers look very good. Maybe you just bent your throttle linkage in your haste to get the RPM back down. Have you tried adjusting the idle to see if things get back to normal? In retro, reading back, you've only described a low idle RPM as the problem. How does it run otherwise?

Rotating the engine backwards. Not a big deal. Rotate it forward and it will probably tighten up.

Thanks for the details, sorry that I misinterpreted your comment. Shouldn't it be called a differential "pressure" test though, since there's no compression involved? Pressure from an air compressor (air compressor compression doesn't count does it?) instead of piston movement. Just sayin'... But cylinder pressure testers are pretty common and inexpensive and the easiest if you don't have an air compressor. Based on the signs, he'll probably get some zeroes or teens and have to pull the head anyway.

He might just mean comparing the cylinder pressure readings between cylinders. It's more important than the actual pressures. All cylinders should create the same pressure, within ~20-25% lowest compared to highest according to the FSM and the Monroe rebuild book (although most people recommend a tighter number). For example, I've had two engines that tested within 2 psi, high to low, at about 175 psi for one and 180 psi for the other. The gauge used will affect the pressure measured though so the comparison is what's important. If you do find a pressure imbalance, a leak-down test would then give you more information about whether it's the head gasket, the rings or the valves.

Over here on the other side of the internet we have to make assumptions about how all of the other parts on your engine are working, so it's easy to miss a critical clue. That's why the methodical approach, with the FSM and a meter, works best, starting from scratch. I still see something that doesn't sound right. You said that you can hear the pump when you turn the key to start. "Start" is when the engine is cranking, so unless you disconnected the small wire at the starter, you wouldn't be able to hear the pump because of the noise from the starter turning the engine. Maybe you mean "Run" or "On" which is the position the key is in right before Start. The pump should not run unless the starter is cranking, or the the engine is running. Maybe you have a relay that's shorted, causing the fuel pump to run even with the key off? Or did you leave the key On when you went in to the store? You never said if the CSV that you took off had constant power causing it to stay open or if it was stuck physically. That would be an important clue. Something weird happened to cause several problems at the same time. CSV stuck, pump running, injectors open... I would break out a multimeter and take some measurements. How much time do you have left?

Somehow Wade must have cursed you when he mentioned that any injector could be open. Amazing. The more symptoms you describe though, the more it becomes apparent that reading the Engine Fuel section of the FSM would really help you out. There are a few things wrong with what just happened. First, the fuel pump should not have power when the key is on unless the engine is running. You couldn't fill your crankcase with gas unless the fuel pump was running. So that's not right. Kind of missed that in Post 1. And, unless the injector is physically jammed open, the only way to get constant fuel flow is if it's constantly grounded since the injectors always have power when the key is on. So your problem might just be a shorted wire on the ground side of the injector circuit. Or it could be a shorted ECU, which happens sometimes. You should get that FSM chapter and a multimeter and do some testing before you install the injectors, you might be wasting time and money. Or, at least, turn the key on with all of the injectors attached to see if they're all stuck or just one, before you install all new injectors. In the beginning, it looked a like a simple problem with a simple solution but now it's looking more complicated. It might be time to get methodical. The FSMs are in ZIP form on the xenons30 site, maybe that's why you couldn't open them. You have to download then unzip them.

Now it's looking like you might have a vacuum leak, a big one. All air must pass through the Air Flow Meter (AFM) otherwise the mixture will be lean and the engine will die or run funny. The crankcase is connected to the intake manifold through the PCV system also, so any leaks there will also be a vacuum leak. The oil filler cap, the dip stick, all vacuum hoses connected to the intake manifold, all must be intact and leak-free. If you've disconnected anything, thinking that you would re-connect it after you got the engine running, reassemble and try again. And check any hoses that you've reefed around while working on the engine to see if they split or cracked. The engine should start right up without messing with the idle screw. Counterclockwise gives a faster idle if you get close and need to keep it running.

On the headlights, if they're like a 280Z, the power is supplied at the combo switch, then runs through it, through the wiring and to the fuse box, on to the headlights, then back to the dimmer switch, where ground is used to choose low or high beam. So if you have continuity through the switch, but no power at the fuse box, then you either don't have power at the switch, or the circuit from the switch to the fuse box is broken. On the 280Zs the main power line to the combo switch runs through a fusible link. I looked at a 240Z wiring diagram but couldn't figure out where the power comes in. On the 280, it's a white with red wire and the fusible link mount is labeled as HL.

Sounds like your cold start valve (CSV) is stuck open. It's either getting voltage all of the time, instead of just at start, or it's physically stuck. Try unplugging the connector and see if it stops. If it stops, the problem is electrical and you can just leave it unplugged. Make sure you insulate the end of the connector though so you don't get a short. If not, you can remove it, block the intake port, and plug the hose,if you're in a hurry. It's only real value is for cold weather starting. It's more of a convenience than a necessity. The CSV is the valve/injector on its own separate fuel line up close to the throttle body. Follow the fuel lines if you're not sure where it is.

Did you see this Tech Article - http://www.classiczcars.com/forums/content.php?r=156-S30-Door-Window-Problems-and-Troubleshooting-Procedures It's very good, might help you out.

The fuel pumps are fairly noisy when running, especially if you're under the car in a quiet garage. I think that you might be looking at a new fuel pump, if you know that you have 12 volts at the wires, but you don't hear it and it doesn't move fuel. They don't like to sit for long, they're at the low point of the tank where the water ends up if it condenses in the tank. The fuel pump was the first part that I had to replace on my car. EFI pumps are expensive. The Ford F150 pump will work, with some modification to the fittings, and is a Bosch pump (late 80s/early 90s are the years to look for I believe), if you have access to a wrecking yard and want to try a cheap one. They're external and located on the driver's side frame rail. The auto stores all want $100+ for an aftermarket replacement. I've read stories of people getting them turning again by removing and cleaning. Might be worth a shot.

I have them on the back wheel cylinders on my 76 (with 78 struts and cylinders) and they work great, especially if you want to flush a lot of fluid through the lines (like, for example, if the car has been sitting for years before you got it). The final bleed seemed fine, the pedal is high and firm.

carpartsmanual suggests that they changed in 76 then stayed the same. At least the date of change is there. There do appear to be some possible errors on the site though, for example, the S30 front hubs are shown as all the same but some 240Zs seem to have a different type. http://www.carpartsmanual.com/datsunS30/DatsunZIndex/Body260Z280Z/2Seater/RadiatorGrilleBumper/tabid/1772/Default.aspx Good luck. I don't think that many people mess with their bumper shocks so finding someone with actual experience with both might be difficult.

Pretty sure that the fuel injection relay is by the hood release handle inside the cabin on the driver's side. It's combined with the fuel pump relay, two plugs in to one relay body. The only relay I see that would be by the battery, close to the voltage regulator (for 1977) is the seat belt relay or the AC compressor relay. If it is a 78 harness though, you'll be missing the voltage regulator (VR) wiring. Maybe the VR is what you're thinking is the fuel injection relay, it's in a similar looking housing.

You could compare drawings from the factory service manuals.

For what it's worth, I've removed mine and haven't noticed any unusual or irritating noises or vibrations. I have an RT-style diff mount also, so with the weight removed and no bottom diff mount, the cross bar with the suspension mounting points is much cleaner plus I have more ground clearance. Extra benefits.

30 Ounce, you're right, apparently, that it's a vibration or noise damper. Maybe it helps with the clunk. But the four plates on the front are stock. They all look like that, like someone learned how to weld while making them. I have a couple sitting n my garage. Many people take them off, and don't notice any difference. Clearance is clearance though. Do you need more than 2 mm?