Zed Head

I agree, I mentioned it mainly for his own future reference so that when he goes to the parts store for an alternator he can ask for the right one. I was also going to mention that the external regulator can put out up to 15.6 volts, adjusted correctly, depending on the temperature according to the FSM. They are kind of an odd mechanical device. I was already over my word limit though. After looking at FW's diagram in her referenced rely thread, I also realized that he might have just blown the fuse, since the headlights are split and fused left and right. The first thing I would do is check the fuse for that headlight, then check the circuit and headlight. A new headlight shouldn't blow from high amps, before the fuse does.

The 1977 came stock with the external regulator. You could look at the spot where the external regulator should be to see if it's still there and plugged in, if you want to be sure of what charging system you have. The voltmeter in the car is probably not correct. Mine was off by a couple of volts, read 16 instead of 14, until I adjusted it via the screws on the back of the meter. Are you sure that the headlight actually burned out? Maybe you have a poor connection somewhere in the circuit (common problem). You can check the headlight with an ohm-meter to see if the filament is intact, or check the headlight circuit at the plug with a volt-meter (probably easier considering how hard it is to get the headlights out).

You can run the pump on 12 volts from your battery with some spare wire to see if the motor turns freely. Some people run water through them to see if they pump. They will run backward so make sure you get the connections right. Watch out for sparks and gasoline. Does gas pour out of the inlet hose to the fuel pump, the one from the tank? I assume that you have it clamped but that would give an indication of whether or not you have a plugged inlet screen. The screen is inside the tank. Take your clamp off and see how much gas comes out. It should flow freely. If not, the problem might be inside the tank. I have used the pump to drain a gas tank, it doesn't gush out but you should get a steady flow. If gas comes out of the tank, and the pump pumps, then you can move up to the fuel filter in the engine bay to see if it flows. The fuel filter is that really big can in the engine bay that has a fuel line running in to the bottom and one out the top to the fuel rail. Break the problem in to pieces and something will pop out, before you pay for parts. Most pumps for fuel-injection are over $100, although there are some junkyard pumps that work, but would be of unknown quality of course.

The relay just directs electrical power to the pump so if you have power at the pump then the relay appears to be working correctly. Are you sure that the engine dies because the fuel pump has stopped turning? You might have a plugged fuel line or filter or inlet screen. You might also have a problem that is not fuel-related. If you could measure the fuel pressure while it was running, that would tell you if you actually had a fuel problem.

This is what I did when my cutoff switch was "on the edge" with the same thought in mind. It worked until I went to get emissions checked. Then I failed, the idle mixture was too rich. I turned the screw back out and passed, and the idle was okay then because I had done some other tuning and it was more stable. The problem started when I advanced my timing. The engine needed less air to maintain RPM at idle. The first thing I did was to adjust the stop for the contact switch in the AFM. It's a very simple mechanism and you can bend the wire with a pair of pliers or a crescent wrench. I could have just set the timing back but I wanted bend the motor to my will...:mad:

So the dieing problem seems to be related to the poor idle. Fix the idle, you'll probably fix the dieing. Your picture shows the side of your throttle body. If you mean the small hose connected to the port in the center of the picture, that would be a ported vacuum source, maybe to your charcoal canister, or the distributor vacuum advance. What is the open end sitting close to? There is another bigger hose that goes to the charcoal canister. If that is open, you might have a vacuum leak. The fuel relay is clicking because the fuel pump contact switch is opening when the vane in the AFM closes as the rpm drop. Mine has done that in the past before I got things tuned up (1976 model with the same AFM switch). That will go away too if you get the engine to idle right. I think the RPM goes up to 1200 when the fuel pump turns off because the mixture leans out, then the RPM surge, the AFM opens, the switch is made and the pump turns on again. Is it running rich or lean at idle? The thermotime switch only comes in to play during starting. Sorry esmit, maybe you're thinking of the water temperature sensor. I would double-check all of your vacuum hoses kjp.

Can't really see a disconnected vacuum hose in your picture. A description of how the engine stalls might give some clues. Does it chug along then die, does it die as soon as you hit the brakes, does it die as soon as press the clutch in, etc.

Points or electronic ignition? Sounds like the car has a different engine in it than stock (electric fuel pump, etc).

Here is one - http://www.zspecialties.com/

Just saw this in the FSM by coincidence.

What happened to the ball? I think that is your pressure relief valve, it comes in to play if your filter gets plugged up and won't flow enough oil. I got curious and looked in the FSM. It says to pry it out with a screwdriver and install the new one by tapping it in. If you had the new one in hand, things might make sense. Page EL-4.

If you had enough backfire pressure in to the intake to blow the hose off of the AFM you might have bent the AFM vane. Datsun put a backfire relief valve in the vane to prevent damage but I would imagine that a big enough backfire might still bend something. See if the vane moves freely, closes all the way, and/or is warped/bent. If you find that the AFM is the problem, doublecheck your firing order and timing before you start it to try to avoid another backfire.

Check your auxiliary air regulator (AAR) for power and operation. It's described in the Engine Fuel section of the FSM. Search the terms on this site and you'll find some recent discussions.

The EFI fusible link is a green wire with a connector on each end, that is in-line from a tap off of the positive terminal of the battery, in the engine bay. Check it for power on the output side, it's hard to tell if they're bad. It looks like the coil and ignition module are on a separate circuit so maybe the car will run on starter fluid with the EFI fusible link blown. Back to what cozye suggested. Page EF-4 in the FSM shows that the injectors, the fuel pump and the air regulator all get power from the EFI/Fuel pump combo relay. I would turn the key to On and see if I had power to the injectors, then open the flap, key still On, and see if I had power to the air regulator plug (the air regulator has a heater inside that turns on when the engine is running), I think that pump might be on the same circuit (according to the big wiring diagram). If you don't have power on the output side of the relay (injectors, air regulator and pump wire), but do have power in, then maybe the relay is bad. If you stare at the diagram long enough you can figure out how to jump it to get power to the fuel pump wire, just for a test (I did it to install a cutoff and priming switch for my pump). Page EF-54 has the procedure for checking the combo relay. Not too difficult if you can reverse things in your head to figure out what pins you're looking at. You can at least check all of the pins on the connector for power to see if you have input power to the relay. If you browse through the Engine Fuel section of the FSM you might get some more ideas.

Thanks cozye, I was writing while you were posting so didn't see yours. And 19-20 mpg is about exactly what I get in my 76. Seems to go up a little in warm weather and down in the cold. By the way, the 75 and 76 (maybe 77) have a combined fuel pump and fuel injection relay. Both relays in one long housing, up above the hood release handle in the cabin. The fuel pump relay takes its signal from the AFM to turn the pump power on. They are expensive.

I'm not sure what you know but the fuel pump only runs when the starter is engaged and when the AFM pump contact switch is made, for 1975. It doesn't run when the key is at On, unless air is flowing through the AFM. So one way to check the power lines to your pump is to disconnect the small wire from the starter and turn the key to Start. The engine won't crank but the fuel pump wire will get power if it is connected and working correctly. If you do that and find that the pump runs, then you can move on to why the injectors aren't opening. Maybe you've already done this. Some people expect the pump to run when they turn the key to On. Another way to check is to take the air intake hose off of the AFM or take the side cover off and rotate the vane while the key is at On. This will get the relay to feed power to the line also. Fuel pump power runs through the fuel injection relay. I don't see a fuse on the diagrams but there might be one.

If you don't have a test light or a voltmeter, then how do you know the pump is not getting power? When you say "no power" do you mean "no noise" from the pump? Or have you checked with a voltmeter? Most auto parts or hardware stores will have a test light for sale. Do you get spark? Will the engine start on starting fluid? If no spark, check your EFI harness fusible links.

There's a chart on this page that gives examples of CR for various block/piston/head combos. http://www.zcarz.us/TechnicalInformationPage.htm I can't vouch for accuracy on the non-stock combinations. Small chart right below the first big block of data. It shows that just the flat tops get you up to ~10.4. The smaller Maxima N47 chamber would be even higher. Here's a link to a calculator. I don't know if it works. - http://www.classiczcars.com/forums/showthread.php?s=&threadid=1292&highlight=L+engine+calculator With carbs, you'll just be back to normal carb and timing tuning, and get what you get. You could try the Maxima N47 but you'll probably have to run low advance on your timing to avoid detonation. I imagine that engine response and fuel economy will suffer but you could do a head swap later if so. An interesting dilemma. I've pondered carbs with some performance mods, since it seems like the cheapest way to get there once you have to leave the stock AFM and ECU behind.

Did the sound just appear out of nowhere? Or did you just do some work on the brakes? If you pried the drums off you might have bent your backing plate. If so, you'll see a white mark on the plate where the drum is rubbing. Also, I believe that Z brakes self-adjust when you use the parking brake.

Looks interesting, at least for an on-the-road spare, especially if you have AC. When is your spring service scheduled? How is it for noise? And price?

What do you mean by weak? The car won't stop quickly? Have you looked at the pads and shoes? Pumping should only help if you have air in the lines. When you pump, you're just pushing more fluid in to compress the air bubbles. If pumping helps, then more bleeding is in order.

That pipe goes in to your engine's crankcase and would normally have a hose connecting it to the PCV valve on the bottom of the intake manifold. The positive pressure is "blowby" (combustion pressure leaking past the rings). At wide open throttle it probably has a lot of positive pressure blowing oil vapor in to your engine bay.

Regarding your firing order: I found this page - http://i26.photobucket.com/albums/c140/mwh5150/Firing-order.jpg in this thread on another forum - http://www.zdriver.com/forum/showthread.php?t=17728 It's the same for all L6's. In your case, I would pick one plug and go around from there, rather than removing them all and restarting. Just to be sure that you don't get them in the right order but off by one spot. If it runs now, you might find two wires switched.

It might be rewired power for your antenna. When I got my car I didn't know what "that noise" from behind me was either. I think my toggle switch was factory though.

Have you looked at yours on the transmission to see if it has worked its way out of the mounting hole? I don't think that the switch is adjustable but you can remove it easily without any gear oil leaking out.