Zed Head

One advantage to doing them cold first is that many, maybe even all of them, will be in spec. when you check them hot. If they are in spec. you don't need to loosen the locknut, just move on to the next one. You will end up only actually adjusting a few of them hot.

Make sure that your voltage regulator is working. Your 260 should have an external regulator unless someone has switched it to an internally regulated alternator. You can probably have it checked at an auto parts store (take the new alternator in with it to confirm it's not damaged) or measure voltage at the battery while the engine is running.

Good work. An L24. Is that the engine in the car or the extra? That's one, what does the other engine show? Back to your original question - it depends. I would use the one that is in the best condition, if i was trying to save some money. Or the L26 if I was looking for more power. What are you trying to do? Good luck with the project.

mike260z, it says on the page that you linked, that the P30 was used for both the 240Z and 260Z. Arne's suggestion gets right to the best way to find out. It is stamped on the block. Right above the starter, a flat spot. You might have to scrape some grime off to read it.

I am not an expert in this. But these two web pages suggest that the motor in your car might already be an L26. Apparently the E88 head was used for the 260Z also. http://datsunzgarage.com/heads/ http://forums.hybridz.org/index.php?showtopic=62691 Here's one more, with block data - http://datsunzgarage.com/engine/index.htm

This thread jumps around but has some good info about deleting the amp gauge and 240Z wiring in general, late in the thread. http://forums.hybridz.org/index.php/topic/96568-alternator-question/page__pid__910910__st__20#entry910910 The wiring diagram for a 78 should help you get the voltmeter in, since it used the internally regulated alternator and a voltmeter. The diagram should show you connections all the way to the alternator.

Copied this from the FSM. Multilingual...

It's looking more and more like timing, either the distributor is off time or the plug wires are off. Sledge, I have found that, in general, if you can line up the two lines on your distributor housing, that your timing will be close. The marks are right next to the adjustment screw/bolt. You'll know what I mean if you look down there. It is also possible to put your distributor in 180 degrees off, although it does not seat very well. If you could get the engine to Top Dead Center and the timing mark at zero, and pull the distributor cap, the rotor should be pointing almost straight ahead. If not, you have timing issues.

Sounds like either fuel or timing, or both. Did you mess with anything else while you were trying to get spark? FastWoman offers a simple, effective test to see if timing and spark are correct. Buy or borrow a can of Starting Fluid, spray some in the manifold and crank it over. You could spray it through a vacuum line if you don't want to pull the big hoses in front of the AFM. Or pour a little raw gasoline in there. If timing and spark are close, it will rev up for a second or two, before dying again.

What was the problem? Details please...

If that is the case, then they probably just deleted one of the BW wires along the way, getting closer to the 1978 version. But back to the reason for failure - did you determine why the first one failed? If your alternator is spiking out high voltage occasionally, it will toast a module immediately. If you had a cause for the first failure and did not find it/fix it, you might have just wasted another. A bad ground at the module can waste one also. You weren't really clear on when the 20 minutes, then no start happened. Was that with the first one that failed, now you have a new one that has not worked at all? Or did one fail, then the new one ran for 20 minutes, now no spark. It sounds like you were diligent with getting the right part and connecting it the same way. You should probably go back to the original problem when the first one died and see if you missed something. Time for Christmas lights...

Edit - I'm still slow. Edit 2 - Wilson, if you get the MSA plug, it's just unplug the external reg., plug the adapter in and follow the directions for connecting the other wires. You don't even need to remove the old external reg. unless you want to. FastWoman, I think by "e" he means the E which is hidden under the spark plug wire (?) in his picture. Earth, i.e Ground. It is there to ground the alt. housing. It is not a good connection point for all of your other grounds, ground to the block or frame or a junction block connected to your negative terminal. Wilson, I would buy that plug from MSA first and use it to do your internal reg, alt. swap. It just takes the place of your external voltage regulator AND it already contains the diode. It would be the simplest way to go. You'll have to get some Chevy hardware though for your new alternator, that mounting bracket in your picture is elegant (I like it) but looks like it fits Datsun. The ammeter and junction point for future loads can be handled individually and separately. You have a lot of stuff going on.

You said a 77 ICM, but what year is your car? 1978 only had five wires to the ICM, the five colors you listed. Maybe they went to 78 wiring in late 77? If you really only have five wires from the harness, then the 78 ICM would most likely work. Green and Red to distributor, BW is power to ICM and coil, B is ground and L (blue) is coil negative. I might be wrong about using other ICMs in your car. 78 works in a 76 (if you leave out a pickup coil) and 76 would work in a 78 (with extra terminals left on the 76 ICM). But 77 has an extra power wire (BW) to the ICM (as you have found). It would take some study to figure out if it can be worked around. But your five colors match 1978. If you have a 77 ICM and left one of the BW terminals unconnected, that could be your problem. By the way, if you are looking at your Build Date to determine the year of your car, a late 77 Build would be an early 78 model. Edit - I'm a slow writer. Reiteration - you might have 1978 wiring! If you have a module with a spot for BW (power) and it's not powered, it probably won't work. You need a module that will work with five wires. Probably 1978...

That other thread was so long that I forgot that Wilson started it! Oops. I guess he's looking for a new perspective, I thought Mr. Hines gave some good advice. Wilson, is that 240Z alternator rigged on to your small block chevy? Then you do have the external regulator to deal with, unless someone has already swapped a modern alt. in. Or you might need that plug or you can try the Atlanticz rewiring. You mentioned headlights though, so you'll probably need a relay to take those off the factory harness.

I was going to paste a link to a thread at Hybridz that would help you out but see that you are already there. Did you read Post #17? The amps only matter if you add new loads to the harness. http://forums.hybridz.org/index.php/topic/96568-alternator-question/ I hope that you're using one of these. If that's the stock 73 alternator (I can't tell) then you'll have an external voltage regulator to deal with. Do that, then just add a wire to a junction point for the charge wire to connect to and wire all of your new loads to that. Edit #2 - this is listed for the 60 amp upgrade but it will probably handle your 105 amp alt. Zsondabrain would know for sure. Either way, the 105 amp alt. is not a drop-in swap. http://www.thezstore.com/page/TZS/PROD/12-4068 The ammeter vs. voltmeter issues discussed in the Hybridz thread are a whole different problem. edit - Dang, FW and cozye are fast. FW, the above was written as you posted...

It means that your coil is probably good, and if the engine turns over, it should supply a spark, if the module lets it. The ignition module is looking more suspect. The pickup coil is easy to check though, I would do that next. ~720 ohms across the red and green wires to the distributor, disconnected at the junction. If the pickup coil checks out, and it worked before and you're sure that all of the wires are connected the same as before, then signs are pointing to a bad module as jm suggested. The modules are kind of sensitive and can just die, especially after 33 years. No offense, but the Chrysler or GM HEI module swap might be difficult for you, they are easy to destroy if you make a mistake in wiring. There are several tests that you can do at the ignition module, on the wiring harness, to check your wiring and components at the same time. It's all described in the Engine Electrical section of the FSM. 75, 76 and 77 modules are similar and you could probably wire one of those in without too much trouble, just match wire colors (you'll have extra terminals on the 76). A 78 would work but you'll need to splice in to the plug, they went from screws to plug-in. Match wire colors again. Ignition problems are tough...

Put the positive probe of the multimeter on the + terminal of the coil,and the negative probe of the multimeter to ground (the engine block or manifold). If you get about 12 volts that means you have power to the coil and a charged battery. Then put the positive probe on the - terminal of the coil and the negative probe to ground. You should get ~ 12 volts. This means that your coil is probably okay. Then you'll know that you have power to the coil and through the coil. If so, you can move on to figuring out why it doesn't fire. jmortensen has a good observation about the module. Personally, I have only had two go bad, one just died completely while driving down the road (1972 Dodge Dart Sport - after a bad voltage regulator did damage) and the other started cutting out at high rpm (1976 280Z after a bad internally regulated alternator voltage regulator did damage). Have you had voltage regulator problems lately, or has your voltmeter been sitting at the high end of the gauge?

Maybe he was doing the SNL "Reaaalllyy" thing... Could have waited at least an hour though. If you have 12 at both sides of the coil, you need to make sure that you have 12 to the module and that you have a good connection from the coil negative to the module (runs all the way back through the harness to the passenger side of the cabin), and that the module ground is good, and that the pickup coil works correctly. The module just sits there waiting for the pickup coil to send a voltage pulse (simplified) then it breaks the circuit. In the meantime, it is supplying the ground that lets current flow through the coil. You might have to take a look at the wiring diagram to get the colors for the wires at the module, so you can test power, ground, coil negative and distributor. Those wires run out to the distributor and coil. When you say new module, you mean new 77 module, not new MSD module, right?

The coil needs 12 volts at each terminal when the key is on. When the pick up coil triggers the ignition module,the module breaks the circuit, releasing the spark. So you must be missing one of those key items - 12 volts through the coil, distributor pick up coil sending trigger voltage to module, or module breaking the circuit. Edit - the coil needs 12 volts at Start also, There typically is a bypass circuit that avoids accessories when Starting. Hook up your test light or volt-meter to the coil terminals and turn the key to On and Start. If you get 12 volts you can move on to the circuit-breaking step. You list the cars below in your profile. Is it one of those? There are a variety of triggering mechanisms for a variety of ignition modules out there. Some can be tested. 1990 Nissan 300zx 1984 Olds Cutlass Supreme 307 V8 Vin Y Looking for another 300ZX Looking for Datsun Z Looking for 350Z Wrecked

You might have a short on the negative side of the coil. Current runs through the primary windings of the coil to charge up the secondary windings. The MSD breaks the circuit to the primary to fire the secondary, creating spark. Not technically rigorous but essentially what happens. If your coil is getting hot it's because there is too much current flowing through the primary windings, all the time. It could be shorting through the MSD unit or a crusty wire or a dirty terminal or through anything else you have connected to the negative terminal (aftermarket tach? or whatever). This would make your coil hot but not give spark since the MSD can't break the circuit. Forgot to say if you're measuring 10 volts this could also be signs of a short. Full disclosure - This not an area of expertise for me...

You know, it's possible that your motor runs perfectly by 1978 standards. We might all just be spoiled by today's numbingly smooth modern machines. Or fuel quality has changed and your motor really is running lean. They say that today's E10 and E15 is not "noticed" by today's engines but they all have O2 and knock sensors feeding smart computers to keep the ratios correct. The E85 guys all run a whole extra set of injectors or really big ones to make their engines work, so it's just a question of how much leaner is E10 or E15, and the effect on your idle. Maybe it's not capacitor drift but fuel composition drift. The topic has been well-worn re gas mileage but I haven't seen much on little things like idle quality, etc. Nothing wrong with some new technology to get things back in sync.

You said you get a firm pedal but this might still be worth checking. It happens occasionally and is easy to do. Is the bleed screw on the top of the caliper? On some (many) model years, 76 for sure, the calipers will bolt up perfectly on the wrong sides, putting the bleed screw at the bottom. This leaves an air pocket above the bleed screw which is impossible to remove completely. Brakleen is a strong solvent and will swell rubber, I believe. Maybe you gummed up the caliper seals or the master, if they were exposed to it? Hopefully you had everything disconnected when you were flushing the lines.

Actually, it's two replays in one housing. The fuel pump relay and the fuel injection relay. You should have power from the ignition switch to that relay when you turn the key to On. Then the relay will allow power to go to the fuel pump when the AFM contact is closed. It might be worth your time to take the hose off of the front of the AFM, turn the key to On and open the AFM flap. If you have power to the relay, the fuel pump will turn on. If it does, then you'll know you have at least one correct fuel pump circuit.

The unconnected dangling white wires by the ECU (computer) are common. They don't need to connect to anything,they are probably for diagnostics or quality assurance at the factory. I don't know for sure, I have not seen a solid explanation. But I have them and so do others. Don't worry about them. In the FSM, most or all of the wiring diagrams have the wires labeled with a letter. The colors that go with the letters are generally shown down at the lower right hand corner of the diagram. G = green, L = blue, WR = white with red stripe, etc. The connectors are also shown and they are color-coded also. So you can follow the wire color to the proper color connector shown in the diagram and you'll know where that wire should go. There are too many wires and connections to try and figure out your problem here. The circuit from your ignition switch to the fuel pump relay is not too complicated. I would start there and at the steering column and the combination switch and ignition switch wiring. The relay is right above the handle to open the hood. It has two connectors attached to it.

KAL7467, I don't want to put a downer on your project but there appears to be some truth to all of the internet chatter about the poor quality of the typical auto store reman'ed alternator. I just replaced a bad O'Reilly alternator with a Datsun OEM alternator from a car that had sat for 10 years. It looked like it had some good usage on it before it sat also, but I had it so I put it on. The O'Reilly Autolite (one of their old brands before they got bought) had always put out low voltage since I bought it, at idle if I had the lights and fan on. The wipers would barely work at idle, I usually turned them off at the stop lights. The ten year old Datsun alternator now runs everything at charging voltage, 14.8, at idle. The wipers scream across the windshield now. They're both 60 amp alternators but the Datsun OEM puts out more amps at idle. I had upgraded from an old worn out alternator so had never actually seen a good one in my car. I'm actually glad that my O'Reilly Autolite died, even though it took out my ignition module in the process. To O'Reilly's credit, they did give me another reman, Ultima brand this time. It's sitting in the garage so I have no idea how it compares. Just something to be aware of.