Zed Head

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.

Is it the urethane that won't squeeze in or the center metal tube? I've found that slipping a couple of greased gasket material scrapers, wood putty appliers, or drywall mud tools (basically any thin piece of stiff metal) between both sides of the bushing and the sides of the mount will help them slide in, at least for the front transverse link bushings.

Looks like texasz is taking the engine and transmission out so he's going to lose some fluid anyway. It might be easier to apply torque to loosen the fill plug while the transmission and engine are in the car. If not, try to loosen it while it's still bolted to the engine. You could easily drag the transmission all over the garage floor trying to loosen the plug. Use a torch to heat the aluminum around the fill plug, it helps a lot. The FSM says 3 1/8 pints.

You should read the Engine Fuel section of the Factory Service Manual (FSM), specifically the part about fuel enrichment. You will see the many ways that extra fuel could be getting in to the engine, and the many components that need to work together to get the engine to run properly. Cold starting should not produce that much extra gas, unless the car did not start and many attempts were made to get it going. You might have a water temperature sensor problem. In general, a working PCV system will evacuate any gas or water vapor that is in the crankcase. The crankcase is under vacuum during running and the gas should vaporize and clear out.

The points have to be grounded to flow current through the coil. I think that they ground through the mounting screws, or a wire off the points bracket (haven't even seen a set of points for many years). Maybe you had a poor ground for the points. Might be worth testing with an ohm-meter to make sure you're not on the edge. Also, as I recall, the condenser used with a points distributor does more than noise reduction. It keeps the points from arcing and pitting by absorbing the first surge of voltage when they close again.

Sticking a screwdriver through the u-joint yoke is an easy way to rotate the driveshaft, to break the nuts loose. Get the wrench on the nut, then get the other end of the wrench pegged against a body part (the car's not yours) stick the screwdriver though the yoke and break the nuts loose by turning the driveshaft with the screw driver. Pretty sure I read the method here or on another forum and I've used it several times. It's easier and more convenient than trying to lock the brakes or put the car in gear.

Just wandering by. I notice that you've measured 12 volts on the + side of the coil, but didn't say what you measured on the - side.

Good news. Hope you didn't have to fight with them too hard to get the exchange. Replace "wasted" with "spent" and "Don't always" with "Don't ever"...

Yes, that's how they generally work. One of them is always hot, so that your brakes always work, key on or off. If you don't have power at either wire then you probably have a blown fuse. If you have power at one but not the other when you press the pedal then the switch is messed up. If the switch works correctly but the lights don't go on, then you probably have bad bulbs or sockets. I have had one socket build up some corrosion, which caused heat,which then melted the socket enough for the spring at the connection to push itself away from the bulb. The switch is in the middle so it's a good place to start to narrow things down. When the Down Under guys wake up they'll probably tell you where the fuse box is on a Skyline.